Search Results

Search found 19441 results on 778 pages for 'static libraries'.

Page 130/778 | < Previous Page | 126 127 128 129 130 131 132 133 134 135 136 137  | Next Page >

• To GAC, or not to GAC?

  - by Jagd

  I have a data access layer (DAL) that is written in ASP.NET 3.5 and uses the Microsoft patterns & practices libraries (hereafter referred to as P&P) in order to accomplish its data access. I installed P&P and it resides in my GAC, so, logically, my DAL references it in the GAC. Therefore, the P&P libraries are never pulled down to the bin folder of my DAL. I use this DAL project in at least five (more than that even, but I'm too lazy to try to count them all) different websites. And this has all worked just fine for me because I'm the only developer who works on these websites. But, now I have other developers who are going to work on some of these websites. The problem: if a developer pulls the DAL project down from our code repository, it won't build for them if they don't have the P&P libraries installed. My question: should I expect the developers to install the P&P libraries, or should I just dump them in the bin folder and be done with it? I realize that dumping them into the bin folder is probably the easiest way to deal with the problem, but I've never been a big fan of the bin folder if I can reference them in the GAC instead.

  Read the article

• How to convert many thousands of lines of VBScript to C#?

  - by Ross Patterson

  I have a collection of about 10,000 small VBScript programs (50-100 lines each) and a small collection of larger ones, and I'm looking for a way to convert them to C# without resorting to by-hand transliteration. The programs are automated test cases for a web application, written for HP/Mercury's QuickTest Pro, and I'm trying to turn them into test cases for Selenium. Luckily, the tests appear to be well-written, using a library of building blocks and idioms (the larger programs), so the test cases actually resemble a domain-specific language more than they do VBScript, and the QTP-ness is well-buried inside the libraries. Ideally, what I'm searching for is a tool that can do the syntactic transformation from VBScript to C# for both the dsl-ish test cases and also the more complicated building-block libraries. That would leave me with a manual cleanup of the libraries, and probably very little work on the test cases. If I could find a VBScript-to-VB.NET translator, I'd take that also, as I suspect I could compile the VB.NET and then de-compile to C# using .NET Relector or something similar. Plan B is to write a translator of my own for the test cases, since they're in a very straight-line style, but it wouldn't help with the libraries. Any suyggestions? I haven't written a compiler in at least 15 years, and while I haven't forgotten how, I'm not looking forward to it - least of all for VBScript!

  Read the article

• Problem with linking in gcc

  - by chitra

  I am compiling a program in which a header file is defined in multiple places. Contents of each of the header file is different, though the variable names are the same internal members within the structures are different . Now at the linking time it is picking up from a library file which belongs to a different header not the one which is used during compilation. Due to this I get an error at link time. Since there are so many libraries with the same name I don't know which library is being picked up. I have lot of oems and other customized libraries which are part of this build. I checked out the options in gcc which talks about selecting different library files to be included. But no where I am able to see an option which talks about which libraries are being picked up the linker. If the linker is able to find more than one library file name, then which does the linker pick up is something which I am not able to understand. I don't want to specify any path, rather I want to understand how the linker is resolving the multiple libraries that it is able to locate. I tried putting -v option, but that doesn't list out the path from which the gcc picks up the library. I am using gcc on linux. Any help in this regard is highly appreciated. Regards, Chitra

  Read the article

• Using maven to distribute a swing application that can have each dependency individually tracked

  - by tms

  I'm moving my project to Maven and eventually OSGi. I currently distribute the project is a large Zip file with all the dependencies. Although my projects code is only 20% of the total package I have to redistribute all the dependency. With smaller independent modules this may be even less. Looking here on stack overflow it seems that to keep my current plan the maven-assembly-plugin should do the trick. I was considering having a base installer that would look at a XML manifest, then collect all the libraries that needed to be updated. This would mean that libraries that change occasionally would be downloaded less often. This also makes since for something like OSGi plugins (which could have independent release schedules). In essence I want my software to look and manage individual libraries, and download on demand (based on the manifest). I was wondering if there is a "maven way" of generating this Manifest and publishing all the libraries to a website? I believe the deploy life-cycle would do the second step. As an alternative, is there a OpenSource Java library that does this type of deployment? I don't want to embed Maven or something larger with the distributed code. The application is not for coders, the simpler the better, and the smaller the installer the better.

  Read the article

• Windows loader problem - turn on verbose mode

  - by doobop

  Hi, I'm in the process of reorganizing some of the legacy libraries in our application which has unmanaged code calling into libraries of managed code. While I have the code reorganized, it produces the following loader error: ... 'app.exe': Loaded 'C:\WINDOWS\system32\CsDisp.dll' 'app.exe': Loaded 'C:\WINDOWS\system32\psapi.dll' 'app.exe': Loaded 'C:\WINDOWS\system32\shell32.dll' 'app.exe': Loaded 'C:\appCode\Debug\daq206_32.dll', Binary was not built with debug information. 'app.exe': Loaded 'C:\appCode\Debug\SiUSBXp.dll', Binary was not built with debug information. 'app.exe': Loaded 'C:\appCode\Debug\AdlinkDAQ.dll', Symbols loaded. 'app.exe': Loaded 'C:\WINDOWS\system32\P9842.dll', Binary was not built with debug information. LDR: LdrRelocateImageWithBias() failed 0xc0000018 LDR: OldBase : 10000000 LDR: NewBase : 00A80000 LDR: Diff : 0x7c90d6fa0012f6cc LDR: NextOffset : 00000000 LDR: *NextOffset : 0x0 LDR: SizeOfBlock : 0xa80000 Debugger:: An unhandled non-continuable exception was thrown during process load I believe 0xc0000018 error is an overlapping address range. So, I have two questions. First, what linker options may cause this error? I'm currently linking with /DYNAMICBASE:NO and /FIXED:No as this was how some of the previous libraries were set up. Second, is there a way to turn on verbose mode for the loader so I can see what exactly it's trying to load? P9842 is a third party library so I imagine it is getting to one of my libraries after P9842 and failing on that one. Can I narrow it down? Thanks.

  Read the article

• Boost::Thread linking error on OSX?

  - by gct

  So I'm going nuts trying to figure this one out. Here's my basic setup: I'm compiling a shared library with a bunch of core functionality that uses a lot of boost stuff. We'll call this library libpf_core.so. It's linked with the boost static libraries, specifically the python, system, filesystem, thread, and program_options libraries. This all goes swimmingly. Now, I have a little test program called test_socketio which is compiled into a shared library (it's loaded as a plugin at runtime). It uses some boost stuff like boost::bind and boost::thread, and it's linked again libpf_core.so (which has the boost libraries included remember). When I go to compile test_socketio though, out of all my plugins it gives me a linking error: [ Building test_socketio ] g++ -c -pg -g -O0 -I/usr/local/include -I../include test_socketio.cc -o test_socketio.o g++ -shared test_socketio.o -lpy_core -o test_socketio.so Undefined symbols: "boost::lock_error::lock_error()", referenced from: boost::unique_lock<boost::mutex>::lock() in test_socketio.o ld: symbol(s) not found collect2: ld returned 1 exit status And I'm going crazy trying to figure out why this is. I've tried explicitly linking boost::thread into the plugin to no avail, tried ensuring that I'm using the boost headers associated with the libraries linked into libpf_core.so in case there was a conflict there. Is there something OSX specific regarding boost that I'm missing? In my searching on google I've seen a number of other people get this error but no one seems to have come up with a satisfactory solution.

  Read the article

• What is the best approach to embed mp4 for the iPhone without using JavaScript?

  - by usingtechnology

  I am trying to troubleshoot this code and am running into a dead-end, so I thought I would ask my first question here. I have three questions: 1) What is the best approach to embed an mp4 for an iPhone specific view, preferably without using Javascript? 2) Are there any preferred practices to debug code on an iPhone? 3) Can anyone tell me what is wrong with my specific code below? I should mention upfront that the variable $fileName does indeed contain the correct info, I've just omitted that portion of the code. Also, the poster image does flicker for a brief moment before I receive the greyed out, broken QuickTime image so that is an indication that this is partially working. Code: <object width="448" height="335" classid="clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B" codebase="http://www.apple.com/qtactivex/qtplugin.cab"> <param name="src" value="/libraries/images/$fileName.jpg" /> <param name="href" value="/libraries/media/$fileName.mp4" /> <param name="target" value="myself" /> <param name="controller" value="true" /> <param name="autoplay" value="false" /> <param name="scale" value="aspect" /> <embed src="/libraries/images/$fileName.jpg" href="/libraries/media/$fileName.mp4" type="video/mp4" target="myself" width="448" height="335" scale="aspect" controller="false" autoplay="false"> </embed> </object>

  Read the article

• javafx tableview get selected data from ObservableList

  - by user3717821

  i am working on a javafx project and i need your help . while i am trying to get selected data from table i can get selected data from normal cell but can't get data from ObservableList inside tableview. code for my database: -- phpMyAdmin SQL Dump -- version 4.0.4 -- http://www.phpmyadmin.net -- -- Host: localhost -- Generation Time: Jun 10, 2014 at 06:20 AM -- Server version: 5.1.33-community -- PHP Version: 5.4.12 SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO"; SET time_zone = "+00:00"; /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */; /*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */; /*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */; /*!40101 SET NAMES utf8 */; -- -- Database: `test` -- -- -------------------------------------------------------- -- -- Table structure for table `customer` -- CREATE TABLE IF NOT EXISTS `customer` ( `col0` int(11) NOT NULL, `col1` varchar(255) DEFAULT NULL, `col2` int(11) DEFAULT NULL, PRIMARY KEY (`col0`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; -- -- Dumping data for table `customer` -- INSERT INTO `customer` (`col0`, `col1`, `col2`) VALUES (12, 'adasdasd', 231), (22, 'adasdasd', 231), (212, 'adasdasd', 231); /*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */; /*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */; /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */; my javafx codes: import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Map; import javafx.application.Application; import javafx.beans.property.SimpleStringProperty; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.TableCell; import javafx.scene.control.TableColumn; import javafx.scene.control.TableColumn.CellDataFeatures; import javafx.scene.control.TablePosition; import javafx.scene.control.TableView; import javafx.scene.control.TableView.TableViewSelectionModel; import javafx.scene.control.cell.ChoiceBoxTableCell; import javafx.scene.control.cell.TextFieldTableCell; import javafx.scene.layout.BorderPane; import javafx.stage.Stage; import javafx.util.Callback; import javafx.util.StringConverter; class DBConnector { private static Connection conn; private static String url = "jdbc:mysql://localhost/test"; private static String user = "root"; private static String pass = "root"; public static Connection connect() throws SQLException{ try{ Class.forName("com.mysql.jdbc.Driver").newInstance(); }catch(ClassNotFoundException cnfe){ System.err.println("Error: "+cnfe.getMessage()); }catch(InstantiationException ie){ System.err.println("Error: "+ie.getMessage()); }catch(IllegalAccessException iae){ System.err.println("Error: "+iae.getMessage()); } conn = DriverManager.getConnection(url,user,pass); return conn; } public static Connection getConnection() throws SQLException, ClassNotFoundException{ if(conn !=null && !conn.isClosed()) return conn; connect(); return conn; } } public class DynamicTable extends Application{ Object newValue; //TABLE VIEW AND DATA private ObservableList<ObservableList> data; private TableView<ObservableList> tableview; //MAIN EXECUTOR public static void main(String[] args) { launch(args); } //CONNECTION DATABASE public void buildData(){ tableview.setEditable(true); Callback<TableColumn<Map, String>, TableCell<Map, String>> cellFactoryForMap = new Callback<TableColumn<Map, String>, TableCell<Map, String>>() { @Override public TableCell call(TableColumn p) { return new TextFieldTableCell(new StringConverter() { @Override public String toString(Object t) { return t.toString(); } @Override public Object fromString(String string) { return string; } }); } }; Connection c ; data = FXCollections.observableArrayList(); try{ c = DBConnector.connect(); //SQL FOR SELECTING ALL OF CUSTOMER String SQL = "SELECT * from CUSTOMer"; //ResultSet ResultSet rs = c.createStatement().executeQuery(SQL); /********************************** * TABLE COLUMN ADDED DYNAMICALLY * **********************************/ for(int i=0 ; i<rs.getMetaData().getColumnCount(); i++){ //We are using non property style for making dynamic table final int j = i; TableColumn col = new TableColumn(rs.getMetaData().getColumnName(i+1)); if(j==1){ final ObservableList<String> logLevelList = FXCollections.observableArrayList("FATAL", "ERROR", "WARN", "INFO", "INOUT", "DEBUG"); col.setCellFactory(ChoiceBoxTableCell.forTableColumn(logLevelList)); tableview.getColumns().addAll(col); } else{ col.setCellValueFactory(new Callback<CellDataFeatures<ObservableList,String>,ObservableValue<String>>(){ public ObservableValue<String> call(CellDataFeatures<ObservableList, String> param) { return new SimpleStringProperty(param.getValue().get(j).toString()); } }); tableview.getColumns().addAll(col); } if(j!=1) col.setCellFactory(cellFactoryForMap); System.out.println("Column ["+i+"] "); } /******************************** * Data added to ObservableList * ********************************/ while(rs.next()){ //Iterate Row ObservableList<String> row = FXCollections.observableArrayList(); for(int i=1 ; i<=rs.getMetaData().getColumnCount(); i++){ //Iterate Column row.add(rs.getString(i)); } System.out.println("Row [1] added "+row ); data.add(row); } //FINALLY ADDED TO TableView tableview.setItems(data); }catch(Exception e){ e.printStackTrace(); System.out.println("Error on Building Data"); } } @Override public void start(Stage stage) throws Exception { //TableView Button showDataButton = new Button("Add"); showDataButton.setOnAction(new EventHandler<ActionEvent>() { public void handle(ActionEvent event) { ObservableList<String> row = FXCollections.observableArrayList(); for(int i=1 ; i<=3; i++){ //Iterate Column row.add("asdasd"); } data.add(row); //FINALLY ADDED TO TableView tableview.setItems(data); } }); tableview = new TableView(); buildData(); //Main Scene BorderPane root = new BorderPane(); root.setCenter(tableview); root.setBottom(showDataButton); Scene scene = new Scene(root,500,500); stage.setScene(scene); stage.show(); tableview.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() { @Override public void changed(ObservableValue observableValue, Object oldValue, Object newValue) { //Check whether item is selected and set value of selected item to Label if (tableview.getSelectionModel().getSelectedItem() != null) { TableViewSelectionModel selectionModel = tableview.getSelectionModel(); ObservableList selectedCells = selectionModel.getSelectedCells(); TablePosition tablePosition = (TablePosition) selectedCells.get(0); Object val = tablePosition.getTableColumn().getCellData(newValue); System.out.println("Selected Value " + val); System.out.println("Selected row " + newValue); } } }); } } please help me..

  Read the article

• Interesting articles and blogs on SPARC T4

  - by mv

  Interesting articles and blogs on SPARC T4 processor   I have consolidated all the interesting information I could get on SPARC T4 processor and its hardware cryptographic capabilities.  Hope its useful. 1. Advantages of SPARC T4 processor  Most important points in this T4 announcement are : "The SPARC T4 processor was designed from the ground up for high speed security and has a cryptographic stream processing unit (SPU) integrated directly into each processor core. These accelerators support 16 industry standard security ciphers and enable high speed encryption at rates 3 to 5 times that of competing processors. By integrating encryption capabilities directly inside the instruction pipeline, the SPARC T4 processor eliminates the performance and cost barriers typically associated with secure computing and makes it possible to deliver high security levels without impacting the user experience." Data Sheet has more details on these  : "New on-chip Encryption Instruction Accelerators with direct non-privileged support for 16 industry-standard cryptographic algorithms plus random number generation in each of the eight cores: AES, Camellia, CRC32c, DES, 3DES, DH, DSA, ECC, Kasumi, MD5, RSA, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512" I ran "isainfo -v" command on Solaris 11 Sparc T4-1 system. It shows the new instructions as expected  : $ isainfo -v 64-bit sparcv9 applications crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5 camellia kasumi des aes ima hpc vis3 fmaf asi_blk_init vis2 vis popc 32-bit sparc applications crc32c cbcond pause mont mpmul sha512 sha256 sha1 md5 camellia kasumi des aes ima hpc vis3 fmaf asi_blk_init vis2 vis popc v8plus div32 mul32  2.  Dan Anderson's Blog have some interesting points about how these can be used : "New T4 crypto instructions include: aes_kexpand0, aes_kexpand1, aes_kexpand2,         aes_eround01, aes_eround23, aes_eround01_l, aes_eround_23_l, aes_dround01, aes_dround23, aes_dround01_l, aes_dround_23_l.       Having SPARC T4 hardware crypto instructions is all well and good, but how do we access it ?      The software is available with Solaris 11 and is used automatically if you are running Solaris a SPARC T4.  It is used internally in the kernel through kernel crypto modules.  It is available in user space through the PKCS#11 library." 3.   Dans' Blog on Where's the Crypto Libraries? Although this was written in 2009 but still is very useful  "Here's a brief tour of the major crypto libraries shown in the digraph:   The libpkcs11 library contains the PKCS#11 API (C_\*() functions, such as C_Initialize()). That in turn calls library pkcs11_softtoken or pkcs11_kernel, for userland or kernel crypto providers. The latter is used mostly for hardware-assisted cryptography (such as n2cp for Niagara2 SPARC processors), as that is performed more efficiently in kernel space with the "kCF" module (Kernel Crypto Framework). Additionally, for Solaris 10, strong crypto algorithms were split off in separate libraries, pkcs11_softtoken_extra libcryptoutil contains low-level utility functions to help implement cryptography. libsoftcrypto (OpenSolaris and Solaris Nevada only) implements several symmetric-key crypto algorithms in software, such as AES, RC4, and DES3, and the bignum library (used for RSA). libmd implements MD5, SHA, and SHA2 message digest algorithms" 4. Difference in T3 and T4 Diagram in this blog is good and self explanatory. Jeff's blog also highlights the differences  "The T4 servers have improved crypto acceleration, described at https://blogs.oracle.com/DanX/entry/sparc_t4_openssl_engine. It is "just built in" so administrators no longer have to assign crypto accelerator units to domains - it "just happens". Every physical or virtual CPU on a SPARC-T4 has full access to hardware based crypto acceleration at all times. .... For completeness sake, it's worth noting that the T4 adds more crypto algorithms, and accelerates Camelia, CRC32c, and more SHA-x." 5. About performance counters In this blog, performance counters are explained : "Note that unlike T3 and before, T4 crypto doesn't require kernel modules like ncp or n2cp, there is no visibility of crypto hardware with kstats or cryptoadm. T4 does provide hardware counters for crypto operations.  You can see these using cpustat: cpustat -c pic0=Instr_FGU_crypto 5 You can check the general crypto support of the hardware and OS with the command "isainfo -v". Since T4 crypto's implementation now allows direct userland access, there are no "crypto units" visible to cryptoadm.  " For more details refer Martin's blog as well. 6. How to turn off  SPARC T4 or Intel AES-NI crypto acceleration  I found this interesting blog from Darren about how to turn off  SPARC T4 or Intel AES-NI crypto acceleration. "One of the new Solaris 11 features of the linker/loader is the ability to have a single ELF object that has multiple different implementations of the same functions that are selected at runtime based on the capabilities of the machine.   The alternate to this is having the application coded to call getisax(2) system call and make the choice itself.  We use this functionality of the linker/loader when we build the userland libraries for the Solaris Cryptographic Framework (specifically libmd.so and libsoftcrypto.so) The Solaris linker/loader allows control of a lot of its functionality via environment variables, we can use that to control the version of the cryptographic functions we run.  To do this we simply export the LD_HWCAP environment variable with values that tell ld.so.1 to not select the HWCAP section matching certain features even if isainfo says they are present.  This will work for consumers of the Solaris Cryptographic Framework that use the Solaris PKCS#11 libraries or use libmd.so interfaces directly.  For SPARC T4 : export LD_HWCAP="-aes -des -md5 -sha256 -sha512 -mont -mpul" .. For Intel systems with AES-NI support: export LD_HWCAP="-aes"" Note that LD_HWCAP is explained in  http://docs.oracle.com/cd/E23823_01/html/816-5165/ld.so.1-1.html "LD_HWCAP, LD_HWCAP_32, and LD_HWCAP_64 -  Identifies an alternative hardware capabilities value... A “-” prefix results in the capabilities that follow being removed from the alternative capabilities." 7. Whitepaper on SPARC T4 Servers—Optimized for End-to-End Data Center Computing This Whitepaper on SPARC T4 Servers—Optimized for End-to-End Data Center Computing explains more details.  It has DTrace scripts which may come in handy : "To ensure the hardware-assisted cryptographic acceleration is configured to use and working with the security scenarios, it is recommended to use the following Solaris DTrace script. #!/usr/sbin/dtrace -s pid$1:libsoftcrypto:yf*:entry, pid$target:libsoftcrypto:rsa*:entry, pid$1:libmd:yf*:entry { @[probefunc] = count(); } tick-1sec { printa(@ops); trunc(@ops); }" Note that I have slightly modified the D Script to have RSA "libsoftcrypto:rsa*:entry" as well as per recommendations from Chi-Chang Lin. 8. References http://www.oracle.com/us/corporate/features/sparc-t4-announcement-494846.html http://www.oracle.com/us/products/servers-storage/servers/sparc-enterprise/t-series/sparc-t4-1-ds-487858.pdf https://blogs.oracle.com/DanX/entry/sparc_t4_openssl_engine https://blogs.oracle.com/DanX/entry/where_s_the_crypto_libraries https://blogs.oracle.com/darren/entry/howto_turn_off_sparc_t4 http://docs.oracle.com/cd/E23823_01/html/816-5165/ld.so.1-1.html   https://blogs.oracle.com/hardware/entry/unleash_the_power_of_cryptography https://blogs.oracle.com/cmt/entry/t4_crypto_cheat_sheet https://blogs.oracle.com/martinm/entry/t4_performance_counters_explained  https://blogs.oracle.com/jsavit/entry/no_mau_required_on_a http://www.oracle.com/us/products/servers-storage/servers/sparc-enterprise/t-series/sparc-t4-business-wp-524472.pdf

  Read the article

• Code Contracts: Hiding ContractException

  - by DigiMortal

  It’s time to move on and improve my randomizer I wrote for an example of static checking of code contracts. In this posting I will modify contracts and give some explanations about pre-conditions and post-conditions. Also I will show you how to avoid ContractExceptions and how to replace them with your own exceptions. As a first thing let’s take a look at my randomizer. public class Randomizer {     public static int GetRandomFromRange(int min, int max)     {         var rnd = new Random();         return rnd.Next(min, max);     }       public static int GetRandomFromRangeContracted(int min, int max)     {         Contract.Requires(min < max, "Min must be less than max");           var rnd = new Random();         return rnd.Next(min, max);     } } We have some problems here. We need contract for method output and we also need some better exception handling mechanism. As ContractException as type is hidden from us we have to switch from ContractException to some other Exception type that we can catch. Adding post-condition Pre-conditions are contracts for method’s input interface. Read it as follows: pre-conditions make sure that all conditions for method’s successful run are met. Post-conditions are contracts for output interface of method. So, post-conditions are for output arguments and return value. My code misses the post-condition that checks return value. Return value in this case must be greater or equal to minimum value and less or equal to maximum value. To make sure that method can run only the correct value I added call to Contract.Ensures() method. public static int GetRandomFromRangeContracted(int min, int max) {     Contract.Requires(min < max, "Min must be less than max");       Contract.Ensures(         Contract.Result<int>() >= min &&         Contract.Result<int>() <= max,         "Return value is out of range"     );       var rnd = new Random();     return rnd.Next(min, max); } I think that the line I added does not need any further comments. Avoiding ContractException for input interface ContractException lives in hidden namespace and we cannot see it at design time. But it is common exception type for all contract exceptions that we do not switch over to some other type. The case of Contract.Requires() method is simple: we can tell it what kind of exception we need if something goes wrong with contract it ensures. public static int GetRandomFromRangeContracted(int min, int max) {     Contract.Requires<ArgumentOutOfRangeException>(         min < max,         "Min must be less than max"     );       Contract.Ensures(         Contract.Result<int>() >= min &&         Contract.Result<int>() <= max,         "Return value is out of range"     );       var rnd = new Random();     return rnd.Next(min, max); } Now, if we violate the input interface contract giving min value that is not less than max value we get ArgumentOutOfRangeException. Avoiding ContractException for output interface Output interface is more complex to control. We cannot give exception type there and hope that this type of exception will be thrown if something goes wrong. Instead we have to use delegate that gathers information about problem and throws the exception we expect to be thrown. From documentation you can find the following example about the delegate I mentioned. Contract.ContractFailed += (sender, e) => {     e.SetHandled();     e.SetUnwind(); // cause code to abort after event     Assert.Fail(e.FailureKind.ToString() + ":" + e.DebugMessage); }; We can use this delegate to throw the Exception. Let’s move the code to separate method too. Here is our method that uses now ContractException hiding. public static int GetRandomFromRangeContracted(int min, int max) {     Contract.Requires(min < max, "Min must be less than max");       Contract.Ensures(         Contract.Result<int>() >= min &&         Contract.Result<int>() <= max,         "Return value is out of range"     );     Contract.ContractFailed += Contract_ContractFailed;       var rnd = new Random();     return rnd.Next(min, max)+1000; } And here is the delegate that creates exception. public static void Contract_ContractFailed(object sender,     ContractFailedEventArgs e) {     e.SetHandled();     e.SetUnwind();       throw new Exception(e.FailureKind.ToString() + ":" + e.Message); } Basically we can do in this delegate whatever we like to do with output interface errors. We can even introduce our own contract exception type. As you can see later then ContractFailed event is very useful at unit testing.

  Read the article

• Generate Strongly Typed Observable Events for the Reactive Extensions for .NET (Rx)

  - by Bobby Diaz

  I must have tried reading through the various explanations and introductions to the new Reactive Extensions for .NET before the concepts finally started sinking in.  The article that gave me the ah-ha moment was over on SilverlightShow.net and titled Using Reactive Extensions in Silverlight.  The author did a good job comparing the "normal" way of handling events vs. the new "reactive" methods. Admittedly, I still have more to learn about the Rx Framework, but I wanted to put together a sample project so I could start playing with the new Observable and IObservable<T> constructs.  I decided to throw together a whiteboard application in Silverlight based on the Drawing with Rx example on the aforementioned article.  At the very least, I figured I would learn a thing or two about a new technology, but my real goal is to create a fun application that I can share with the kids since they love drawing and coloring so much! Here is the code sample that I borrowed from the article: var mouseMoveEvent = Observable.FromEvent<MouseEventArgs>(this, "MouseMove"); var mouseLeftButtonDown = Observable.FromEvent<MouseButtonEventArgs>(this, "MouseLeftButtonDown"); var mouseLeftButtonUp = Observable.FromEvent<MouseButtonEventArgs>(this, "MouseLeftButtonUp");       var draggingEvents = from pos in mouseMoveEvent                              .SkipUntil(mouseLeftButtonDown)                              .TakeUntil(mouseLeftButtonUp)                              .Let(mm => mm.Zip(mm.Skip(1), (prev, cur) =>                                  new                                  {                                      X2 = cur.EventArgs.GetPosition(this).X,                                      X1 = prev.EventArgs.GetPosition(this).X,                                      Y2 = cur.EventArgs.GetPosition(this).Y,                                      Y1 = prev.EventArgs.GetPosition(this).Y                                  })).Repeat()                          select pos;       draggingEvents.Subscribe(p =>     {         Line line = new Line();         line.Stroke = new SolidColorBrush(Colors.Black);         line.StrokeEndLineCap = PenLineCap.Round;         line.StrokeLineJoin = PenLineJoin.Round;         line.StrokeThickness = 5;         line.X1 = p.X1;         line.Y1 = p.Y1;         line.X2 = p.X2;         line.Y2 = p.Y2;         this.LayoutRoot.Children.Add(line);     }); One thing that was nagging at the back of my mind was having to deal with the event names as strings, as well as the verbose syntax for the Observable.FromEvent<TEventArgs>() method.  I came up with a couple of static/helper classes to resolve both issues and also created a T4 template to auto-generate these helpers for any .NET type.  Take the following code from the above example: var mouseMoveEvent = Observable.FromEvent<MouseEventArgs>(this, "MouseMove"); var mouseLeftButtonDown = Observable.FromEvent<MouseButtonEventArgs>(this, "MouseLeftButtonDown"); var mouseLeftButtonUp = Observable.FromEvent<MouseButtonEventArgs>(this, "MouseLeftButtonUp"); Turns into this with the new static Events class: var mouseMoveEvent = Events.Mouse.Move.On(this); var mouseLeftButtonDown = Events.Mouse.LeftButtonDown.On(this); var mouseLeftButtonUp = Events.Mouse.LeftButtonUp.On(this); Or better yet, just remove the variable declarations altogether:     var draggingEvents = from pos in Events.Mouse.Move.On(this)                              .SkipUntil(Events.Mouse.LeftButtonDown.On(this))                              .TakeUntil(Events.Mouse.LeftButtonUp.On(this))                              .Let(mm => mm.Zip(mm.Skip(1), (prev, cur) =>                                  new                                  {                                      X2 = cur.EventArgs.GetPosition(this).X,                                      X1 = prev.EventArgs.GetPosition(this).X,                                      Y2 = cur.EventArgs.GetPosition(this).Y,                                      Y1 = prev.EventArgs.GetPosition(this).Y                                  })).Repeat()                          select pos; The Move, LeftButtonDown and LeftButtonUp members of the Events.Mouse class are readonly instances of the ObservableEvent<TTarget, TEventArgs> class that provide type-safe access to the events via the On() method.  Here is the code for the class: using System; using System.Collections.Generic; using System.Linq;   namespace System.Linq {     /// <summary>     /// Represents an event that can be managed via the <see cref="Observable"/> API.     /// </summary>     /// <typeparam name="TTarget">The type of the target.</typeparam>     /// <typeparam name="TEventArgs">The type of the event args.</typeparam>     public class ObservableEvent<TTarget, TEventArgs> where TEventArgs : EventArgs     {         /// <summary>         /// Initializes a new instance of the <see cref="ObservableEvent"/> class.         /// </summary>         /// <param name="eventName">Name of the event.</param>         protected ObservableEvent(String eventName)         {             EventName = eventName;         }           /// <summary>         /// Registers the specified event name.         /// </summary>         /// <param name="eventName">Name of the event.</param>         /// <returns></returns>         public static ObservableEvent<TTarget, TEventArgs> Register(String eventName)         {             return new ObservableEvent<TTarget, TEventArgs>(eventName);         }           /// <summary>         /// Creates an enumerable sequence of event values for the specified target.         /// </summary>         /// <param name="target">The target.</param>         /// <returns></returns>         public IObservable<IEvent<TEventArgs>> On(TTarget target)         {             return Observable.FromEvent<TEventArgs>(target, EventName);         }           /// <summary>         /// Gets or sets the name of the event.         /// </summary>         /// <value>The name of the event.</value>         public string EventName { get; private set; }     } } And this is how it's used:     /// <summary>     /// Categorizes <see cref="ObservableEvents"/> by class and/or functionality.     /// </summary>     public static partial class Events     {         /// <summary>         /// Implements a set of predefined <see cref="ObservableEvent"/>s         /// for the <see cref="System.Windows.System.Windows.UIElement"/> class         /// that represent mouse related events.         /// </summary>         public static partial class Mouse         {             /// <summary>Represents the MouseMove event.</summary>             public static readonly ObservableEvent<UIElement, MouseEventArgs> Move =                 ObservableEvent<UIElement, MouseEventArgs>.Register("MouseMove");               // additional members omitted...         }     } The source code contains a static Events class with prefedined members for various categories (Key, Mouse, etc.).  There is also an Events.tt template that you can customize to generate additional event categories for any .NET type.  All you should have to do is add the name of your class to the types collection near the top of the template:     types = new Dictionary<String, Type>()     {         //{ "Microsoft.Maps.MapControl.Map, Microsoft.Maps.MapControl", null }         { "System.Windows.FrameworkElement, System.Windows", null },         { "Whiteboard.MainPage, Whiteboard", null }     }; The template is also a bit rough at this point, but at least it generates code that *should* compile.  Please let me know if you run into any issues with it.  Some people have reported errors when trying to use T4 templates within a Silverlight project, but I was able to get it to work with a little black magic...  You can download the source code for this project or play around with the live demo.  Just be warned that it is at a very early stage so don't expect to find much today.  I plan on adding alot more options like pen colors and sizes, saving, printing, etc. as time permits.  HINT: hold down the ESC key to erase! Enjoy! Additional Resources Using Reactive Extensions in Silverlight DevLabs: Reactive Extensions for .NET (Rx) Rx Framework Part III - LINQ to Events - Generating GetEventName() Wrapper Methods using T4

  Read the article

• jBullet Collision/Physics not working correctly

  - by Kenneth Bray

  Below is the code for one of my objects in the game I am creating (yes although this is a cube, I am not making anything remotely like MineCraft), and my issue is I while the cube will display and is does follow the physics if the cube falls, it does not interact with any other objects in the game. If I was to have multiple cubes in screen at once they all just sit there, or shoot off in all directions never stopping. Anyway, I am new to jBullet, and any help would be appreciated. package Object; import static org.lwjgl.opengl.GL11.GL_QUADS; import static org.lwjgl.opengl.GL11.glBegin; import static org.lwjgl.opengl.GL11.glColor3f; import static org.lwjgl.opengl.GL11.glEnd; import static org.lwjgl.opengl.GL11.glPopMatrix; import static org.lwjgl.opengl.GL11.glPushMatrix; import static org.lwjgl.opengl.GL11.glVertex3f; import javax.vecmath.Matrix4f; import javax.vecmath.Quat4f; import javax.vecmath.Vector3f; import com.bulletphysics.collision.shapes.BoxShape; import com.bulletphysics.collision.shapes.CollisionShape; import com.bulletphysics.dynamics.RigidBody; import com.bulletphysics.dynamics.RigidBodyConstructionInfo; import com.bulletphysics.linearmath.DefaultMotionState; import com.bulletphysics.linearmath.Transform; public class Cube { // Cube size/shape variables private float size; boolean cubeCollidable; boolean cubeDestroyable; // Position variables - currently this defines the center of the cube private float posX; private float posY; private float posZ; // Rotation variables - should be between 0 and 359, might consider letting rotation go higher though I can't think of a purpose currently private float rotX; private float rotY; private float rotZ; //collision shape is a box shape CollisionShape fallShape; // setup the motion state for the ball DefaultMotionState fallMotionState; Vector3f fallInertia = new Vector3f(0, 1, 0); RigidBodyConstructionInfo fallRigidBodyCI; public RigidBody fallRigidBody; int mass = 1; // Constructor public Cube(float pX, float pY, float pZ, float pSize) { posX = pX; posY = pY; posZ = pZ; size = pSize; rotX = 0; rotY = 0; rotZ = 0; // define the physics based on the values passed in fallShape = new BoxShape(new Vector3f(size, size, size)); fallMotionState = new DefaultMotionState(new Transform(new Matrix4f(new Quat4f(0, 0, 0, 1), new Vector3f(0, 50, 0), 1f))); fallRigidBodyCI = new RigidBodyConstructionInfo(mass, fallMotionState, fallShape, fallInertia); fallRigidBody = new RigidBody(fallRigidBodyCI); } public void Update() { Transform trans = new Transform(); fallRigidBody.getMotionState().getWorldTransform(trans); posY = trans.origin.x; posX = trans.origin.y; posZ = trans.origin.z; } public void Draw() { fallShape.calculateLocalInertia(mass, fallInertia); // center point posX, posY, posZ float radius = size / 2; //top glPushMatrix(); glBegin(GL_QUADS); { glColor3f(1.0f,0.0f,0.0f); // red glVertex3f(posX + radius, posY + radius, posZ - radius); glVertex3f(posX - radius, posY + radius, posZ - radius); glVertex3f(posX - radius, posY + radius, posZ + radius); glVertex3f(posX + radius, posY + radius, posZ + radius); } glEnd(); glPopMatrix(); //bottom glPushMatrix(); glBegin(GL_QUADS); { glColor3f(1.0f,1.0f,0.0f); // ?? color glVertex3f(posX + radius, posY - radius, posZ + radius); glVertex3f(posX - radius, posY - radius, posZ + radius); glVertex3f(posX - radius, posY - radius, posZ - radius); glVertex3f(posX + radius, posY - radius, posZ - radius); } glEnd(); glPopMatrix(); //right side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(1.0f,0.0f,1.0f); // ?? color glVertex3f(posX + radius, posY + radius, posZ + radius); glVertex3f(posX + radius, posY - radius, posZ + radius); glVertex3f(posX + radius, posY - radius, posZ - radius); glVertex3f(posX + radius, posY + radius, posZ - radius); } glEnd(); glPopMatrix(); //left side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(0.0f,1.0f,1.0f); // ?? color glVertex3f(posX - radius, posY + radius, posZ - radius); glVertex3f(posX - radius, posY - radius, posZ - radius); glVertex3f(posX - radius, posY - radius, posZ + radius); glVertex3f(posX - radius, posY + radius, posZ + radius); } glEnd(); glPopMatrix(); //front side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(0.0f,0.0f,1.0f); //blue glVertex3f(posX + radius, posY + radius, posZ + radius); glVertex3f(posX - radius, posY + radius, posZ + radius); glVertex3f(posX - radius, posY - radius, posZ + radius); glVertex3f(posX + radius, posY - radius, posZ + radius); } glEnd(); glPopMatrix(); //back side glPushMatrix(); glBegin(GL_QUADS); { glColor3f(0.0f,1.0f,0.0f); // green glVertex3f(posX + radius, posY - radius, posZ - radius); glVertex3f(posX - radius, posY - radius, posZ - radius); glVertex3f(posX - radius, posY + radius, posZ - radius); glVertex3f(posX + radius, posY + radius, posZ - radius); } glEnd(); glPopMatrix(); } }

  Read the article

• Microsoft and the open source community

  - by Charles Young

  For the last decade, I have repeatedly, in my imitable Microsoft fan boy style, offered an alternative view to commonly held beliefs about Microsoft's stance on open source licensing.  In earlier times, leading figures in Microsoft were very vocal in resisting the idea that commercial licensing is outmoded or morally reprehensible.  Many people interpreted this as all-out corporate opposition to open source licensing.  I never read it that way. It is true that I've met individual employees of Microsoft who are antagonistic towards FOSS (free and open source software), but I've met more who are supportive or at least neutral on the subject.  In any case, individual attitudes of employees don't necessarily reflect a corporate stance.  The strongest opposition I've encountered has actually come from outside the company.  It's not a charitable thought, but I sometimes wonder if there are people in the .NET community who are opposed to FOSS simply because they believe, erroneously, that Microsoft is opposed. Here, for what it is worth, are the points I've repeated endlessly over the years and which have often been received with quizzical scepticism. a)  A decade ago, Microsoft's big problem was not FOSS per se, or even with copyleft.  The thing which really kept them awake at night was the fear that one day, someone might find, deep in the heart of the Windows code base, some code that should not be there and which was published under GPL.  The likelihood of this ever happening has long since faded away, but there was a time when MS was running scared.  I suspect this is why they held out for a while from making Windows source code open to inspection.  Nowadays, as an MVP, I am positively encouraged to ask to see Windows source. b)  Microsoft has never opposed the open source community.  They have had problems with specific people and organisations in the FOSS community.  Back in the 1990s, Richard Stallman gave time and energy to a successful campaign to launch antitrust proceedings against Microsoft.  In more recent times, the negative attitude of certain people to Microsoft's submission of two FOSS licences to the OSI (both of which have long since been accepted), and the mad scramble to try to find any argument, however tenuous, to block their submission was not, let us say, edifying. c) Microsoft has never, to my knowledge, written off the FOSS model.  They certainly don't agree that more traditional forms of licensing are inappropriate or immoral, and they've always been prepared to say so.  One reason why it was so hard to convince people that Microsoft is not rabidly antagonistic towards FOSS licensing is that so many people think they have no involvement in open source.  A decade ago, there was virtually no evidence of any such involvement.  However, that was a long time ago.  Quietly over the years, Microsoft has got on with the job of working out how to make use of FOSS licensing and how to support the FOSS community.  For example, as well as making increasingly extensive use of Github, they run an important FOSS forge (CodePlex) on which they, themselves, host many hundreds of distinct projects.  The total count may even be in the thousands now.  I suspect there is a limit of about 500 records on CodePlex searches because, for the past few years, whenever I search for Microsoft-specific projects on CodePlex, I always get approx. 500 hits.  Admittedly, a large volume of the stuff they publish under FOSS licences amounts to code samples, but many of those 'samples' have grown into useful and fully featured frameworks, libraries and tools. All this is leading up to the observation that yesterday's announcement by Scott Guthrie marks a significant milestone and should not go unnoticed.  If you missed it, let me summarise.   From the first release of .NET, Microsoft has offered a web development framework called ASP.NET.  The core libraries are included in the .NET framework which is released free of charge, but which is not open source.   However, in recent years, the number of libraries that constitute ASP.NET have grown considerably.  Today, most professional ASP.NET web development exploits the ASP.NET MVC framework.  This, together with several other important parts of the ASP.NET technology stack, is released on CodePlex under the Apache 2.0 licence.   Hence, today, a huge swathe of web development on the .NET/Azure platform relies four-square on the use of FOSS frameworks and libraries. Yesterday, Scott Guthrie announced the next stage of ASP.NET's journey towards FOSS nirvana.  This involves extending ASP.NET's FOSS stack to include Web API and the MVC Razor view engine which is rapidly becoming the de facto 'standard' for building web pages in ASP.NET.  However, perhaps the more important announcement is that the ASP.NET team will now accept and review contributions from the community.  Scott points out that this model is already in place elsewhere in Microsoft, and specifically draws attention to development of the Windows Azure SDKs.  These SDKs are central to Azure development.   The .NET and Java SDKs are published under Apache 2.0 on Github and Microsoft is open to community contributions.  Accepting contributions is a more profound move than simply releasing code under FOSS licensing.  It means that Microsoft is wholeheartedly moving towards a full-blooded open source approach for future evolution of some of their central and most widely used .NET and Azure frameworks and libraries.  In conjunction with Scott's announcement, Microsoft has also released Git support for CodePlex (at long last!) and, perhaps more importantly, announced significant new investment in their own FOSS forge. Here at Solidsoft we have several reasons to be very interested in Scott's announcement. I'll draw attention to one of them.  Earlier this year we wrote the initial version of a new UK Government web application called CloudStore.  CloudStore provides a way for local and central government to discover and purchase applications and services. We wrote the web site using ASP.NET MVC which is FOSS.  However, this point has been lost on the ladies and gentlemen of the press and, I suspect, on some of the decision makers on the government side.  They announced a few weeks ago that future versions of CloudStore will move to a FOSS framework, clearly oblivious of the fact that it is already built on a FOSS framework.  We are, it is fair to say, mildly irked by the uninformed and badly out-of-date assumption that “if it is Microsoft, it can't be FOSS”.  Old prejudices live on.

  Read the article

• More Fun with C# Iterators and Generators

  - by James Michael Hare

  In my last post, I talked quite a bit about iterators and how they can be really powerful tools for filtering a list of items down to a subset of items.  This had both pros and cons over returning a full collection, which, in summary, were:   Pros: If traversal is only partial, does not have to visit rest of collection. If evaluation method is costly, only incurs that cost on elements visited. Adds little to no garbage collection pressure.    Cons: Very slight performance impact if you know caller will always consume all items in collection. And as we saw in the last post, that con for the cost was very, very small and only really became evident on very tight loops consuming very large lists completely.    One of the key items to note, though, is the garbage!  In the traditional (return a new collection) method, if you have a 1,000,000 element collection, and wish to transform or filter it in some way, you have to allocate space for that copy of the collection.  That is, say you have a collection of 1,000,000 items and you want to double every item in the collection.  Well, that means you have to allocate a collection to hold those 1,000,000 items to return, which is a lot especially if you are just going to use it once and toss it.   Iterators, though, don't have this problem.  Each time you visit the node, it would return the doubled value of the node (in this example) and not allocate a second collection of 1,000,000 doubled items.  Do you see the distinction?  In both cases, we're consuming 1,000,000 items.  But in one case we pass back each doubled item which is just an int (for example's sake) on the stack and in the other case, we allocate a list containing 1,000,000 items which then must be garbage collected.   So iterators in C# are pretty cool, eh?  Well, here's one more thing a C# iterator can do that a traditional "return a new collection" transformation can't!   It can return **unbounded** collections!   I know, I know, that smells a lot like an infinite loop, eh?  Yes and no.  Basically, you're relying on the caller to put the bounds on the list, and as long as the caller doesn't you keep going.  Consider this example:   public static class Fibonacci {     // returns the infinite fibonacci sequence     public static IEnumerable<int> Sequence()     {         int iteration = 0;         int first = 1;         int second = 1;         int current = 0;         while (true)         {             if (iteration++ < 2)             {                 current = 1;             }             else             {                 current = first + second;                 second = first;                 first = current;             }             yield return current;         }     } }   Whoa, you say!  Yes, that's an infinite loop!  What the heck is going on there?  Yes, that was intentional.  Would it be better to have a fibonacci sequence that returns only a specific number of items?  Perhaps, but that wouldn't give you the power to defer the execution to the caller.   The beauty of this function is it is as infinite as the sequence itself!  The fibonacci sequence is unbounded, and so is this method.  It will continue to return fibonacci numbers for as long as you ask for them.  Now that's not something you can do with a traditional method that would return a collection of ints representing each number.  In that case you would eventually run out of memory as you got to higher and higher numbers.  This method, though, never runs out of memory.   Now, that said, you do have to know when you use it that it is an infinite collection and bound it appropriately.  Fortunately, Linq provides a lot of these extension methods for you!   Let's say you only want the first 10 fibonacci numbers:       foreach(var fib in Fibonacci.Sequence().Take(10))     {         Console.WriteLine(fib);     }   Or let's say you only want the fibonacci numbers that are less than 100:       foreach(var fib in Fibonacci.Sequence().TakeWhile(f => f < 100))     {         Console.WriteLine(fib);     }   So, you see, one of the nice things about iterators is their power to work with virtually any size (even infinite) collections without adding the garbage collection overhead of making new collections.    You can also do fun things like this to make a more "fluent" interface for for loops:   // A set of integer generator extension methods public static class IntExtensions {     // Begins counting to inifity, use To() to range this.     public static IEnumerable<int> Every(this int start)     {         // deliberately avoiding condition because keeps going         // to infinity for as long as values are pulled.         for (var i = start; ; ++i)         {             yield return i;         }     }     // Begins counting to infinity by the given step value, use To() to     public static IEnumerable<int> Every(this int start, int byEvery)     {         // deliberately avoiding condition because keeps going         // to infinity for as long as values are pulled.         for (var i = start; ; i += byEvery)         {             yield return i;         }     }     // Begins counting to inifity, use To() to range this.     public static IEnumerable<int> To(this int start, int end)     {         for (var i = start; i <= end; ++i)         {             yield return i;         }     }     // Ranges the count by specifying the upper range of the count.     public static IEnumerable<int> To(this IEnumerable<int> collection, int end)     {         return collection.TakeWhile(item => item <= end);     } }   Note that there are two versions of each method.  One that starts with an int and one that starts with an IEnumerable<int>.  This is to allow more power in chaining from either an existing collection or from an int.  This lets you do things like:   // count from 1 to 30 foreach(var i in 1.To(30)) {     Console.WriteLine(i); }     // count from 1 to 10 by 2s foreach(var i in 0.Every(2).To(10)) {     Console.WriteLine(i); }     // or, if you want an infinite sequence counting by 5s until something inside breaks you out... foreach(var i in 0.Every(5)) {     if (someCondition)     {         break;     }     ... }     Yes, those are kinda play functions and not particularly useful, but they show some of the power of generators and extension methods to form a fluid interface.   So what do you think?  What are some of your favorite generators and iterators?

  Read the article

• Nashorn, the rhino in the room

  - by costlow

  Nashorn is a new runtime within JDK 8 that allows developers to run code written in JavaScript and call back and forth with Java. One advantage to the Nashorn scripting engine is that is allows for quick prototyping of functionality or basic shell scripts that use Java libraries. The previous JavaScript runtime, named Rhino, was introduced in JDK 6 (released 2006, end of public updates Feb 2013). Keeping tradition amongst the global developer community, "Nashorn" is the German word for rhino. The Java platform and runtime is an intentional home to many languages beyond the Java language itself. OpenJDK’s Da Vinci Machine helps coordinate work amongst language developers and tool designers and has helped different languages by introducing the Invoke Dynamic instruction in Java 7 (2011), which resulted in two major benefits: speeding up execution of dynamic code, and providing the groundwork for Java 8’s lambda executions. Many of these improvements are discussed at the JVM Language Summit, where language and tool designers get together to discuss experiences and issues related to building these complex components. There are a number of benefits to running JavaScript applications on JDK 8’s Nashorn technology beyond writing scripts quickly: Interoperability with Java and JavaScript libraries. Scripts do not need to be compiled. Fast execution and multi-threading of JavaScript running in Java’s JRE. The ability to remotely debug applications using an IDE like NetBeans, Eclipse, or IntelliJ (instructions on the Nashorn blog). Automatic integration with Java monitoring tools, such as performance, health, and SIEM. In the remainder of this blog post, I will explain how to use Nashorn and the benefit from those features. Nashorn execution environment The Nashorn scripting engine is included in all versions of Java SE 8, both the JDK and the JRE. Unlike Java code, scripts written in nashorn are interpreted and do not need to be compiled before execution. Developers and users can access it in two ways: Users running JavaScript applications can call the binary directly:jre8/bin/jjs This mechanism can also be used in shell scripts by specifying a shebang like #!/usr/bin/jjs Developers can use the API and obtain a ScriptEngine through:ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn"); When using a ScriptEngine, please understand that they execute code. Avoid running untrusted scripts or passing in untrusted/unvalidated inputs. During compilation, consider isolating access to the ScriptEngine and using Type Annotations to only allow @Untainted String arguments. One noteworthy difference between JavaScript executed in or outside of a web browser is that certain objects will not be available. For example when run outside a browser, there is no access to a document object or DOM tree. Other than that, all syntax, semantics, and capabilities are present. Examples of Java and JavaScript The Nashorn script engine allows developers of all experience levels the ability to write and run code that takes advantage of both languages. The specific dialect is ECMAScript 5.1 as identified by the User Guide and its standards definition through ECMA international. In addition to the example below, Benjamin Winterberg has a very well written Java 8 Nashorn Tutorial that provides a large number of code samples in both languages. Basic Operations A basic Hello World application written to run on Nashorn would look like this: #!/usr/bin/jjs print("Hello World"); The first line is a standard script indication, so that Linux or Unix systems can run the script through Nashorn. On Windows where scripts are not as common, you would run the script like: jjs helloWorld.js. Receiving Arguments In order to receive program arguments your jjs invocation needs to use the -scripting flag and a double-dash to separate which arguments are for jjs and which are for the script itself:jjs -scripting print.js -- "This will print" #!/usr/bin/jjs var whatYouSaid = $ARG.length==0 ? "You did not say anything" : $ARG[0] print(whatYouSaid); Interoperability with Java libraries (including 3rd party dependencies) Another goal of Nashorn was to allow for quick scriptable prototypes, allowing access into Java types and any libraries. Resources operate in the context of the script (either in-line with the script or as separate threads) so if you open network sockets and your script terminates, those sockets will be released and available for your next run. Your code can access Java types the same as regular Java classes. The “import statements” are written somewhat differently to accommodate for language. There is a choice of two styles: For standard classes, just name the class: var ServerSocket = java.net.ServerSocket For arrays or other items, use Java.type: var ByteArray = Java.type("byte[]")You could technically do this for all. The same technique will allow your script to use Java types from any library or 3rd party component and quickly prototype items. Building a user interface One major difference between JavaScript inside and outside of a web browser is the availability of a DOM object for rendering views. When run outside of the browser, JavaScript has full control to construct the entire user interface with pre-fabricated UI controls, charts, or components. The example below is a variation from the Nashorn and JavaFX guide to show how items work together. Nashorn has a -fx flag to make the user interface components available. With the example script below, just specify: jjs -fx -scripting fx.js -- "My title" #!/usr/bin/jjs -fx var Button = javafx.scene.control.Button; var StackPane = javafx.scene.layout.StackPane; var Scene = javafx.scene.Scene; var clickCounter=0; $STAGE.title = $ARG.length>0 ? $ARG[0] : "You didn't provide a title"; var button = new Button(); button.text = "Say 'Hello World'"; button.onAction = myFunctionForButtonClicking; var root = new StackPane(); root.children.add(button); $STAGE.scene = new Scene(root, 300, 250); $STAGE.show(); function myFunctionForButtonClicking(){   var text = "Click Counter: " + clickCounter;   button.setText(text);   clickCounter++;   print(text); } For a more advanced post on using Nashorn to build a high-performing UI, see JavaFX with Nashorn Canvas example. Interoperable with frameworks like Node, Backbone, or Facebook React The major benefit of any language is the interoperability gained by people and systems that can read, write, and use it for interactions. Because Nashorn is built for the ECMAScript specification, developers familiar with JavaScript frameworks can write their code and then have system administrators deploy and monitor the applications the same as any other Java application. A number of projects are also running Node applications on Nashorn through Project Avatar and the supported modules. In addition to the previously mentioned Nashorn tutorial, Benjamin has also written a post about Using Backbone.js with Nashorn. To show the multi-language power of the Java Runtime, there is another interesting example that unites Facebook React and Clojure on JDK 8’s Nashorn. Summary Nashorn provides a simple and fast way of executing JavaScript applications and bridging between the best of each language. By making the full range of Java libraries to JavaScript applications, and the quick prototyping style of JavaScript to Java applications, developers are free to work as they see fit. Software Architects and System Administrators can take advantage of one runtime and leverage any work that they have done to tune, monitor, and certify their systems. Additional information is available within: The Nashorn Users’ Guide Java Magazine’s article "Next Generation JavaScript Engine for the JVM." The Nashorn team’s primary blog or a very helpful collection of Nashorn links.

  Read the article

• Refactoring FizzBuzz

  - by MarkPearl

  A few years ago I blogger about FizzBuzz, at the time the post was prompted by Scott Hanselman who had podcasted about how surprized he was that some programmers could not even solve the FizzBuzz problem within a reasonable period of time during a job interview. At the time I thought I would give the problem a go in F# and sure enough the solution was fairly simple – I then also did a basic solution in C# but never posted it. Since then I have learned that being able to solve a problem and how you solve the problem are two totally different things. Today I decided to give the problem a retry and see if I had learnt anything new in the last year or so. Here is how my solution looked after refactoring… Solution 1 – Cheap and Nasty public class FizzBuzzCalculator { public string NumberFormat(int number) { var numDivisibleBy3 = (number % 3) == 0; var numDivisibleBy5 = (number % 5) == 0; if (numDivisibleBy3 && numDivisibleBy5) return String.Format("{0} FizzBuz", number); else if (numDivisibleBy3) return String.Format("{0} Fizz", number); else if (numDivisibleBy5) return String.Format("{0} Buz", number); return number.ToString(); } } class Program { static void Main(string[] args) { var fizzBuzz = new FizzBuzzCalculator(); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } } } My first attempt I just looked at solving the problem – it works, and could be an acceptable solution but tonight I thought I would see how far  I could refactor it… The section I decided to focus on was the mass of if..else code in the NumberFormat method. Solution 2 – Replacing If…Else with a Dictionary public class FizzBuzzCalculator { private readonly Dictionary<Tuple<bool, bool>, string> _mappings; public FizzBuzzCalculator(Dictionary<Tuple<bool, bool>, string> mappings) { _mappings = mappings; } public string NumberFormat(int number) { var numDivisibleBy3 = (number % 3) == 0; var numDivisibleBy5 = (number % 5) == 0; var mappedKey = new Tuple<bool, bool>(numDivisibleBy3, numDivisibleBy5); return String.Format("{0} {1}", number, _mappings[mappedKey]); } } class Program { static void Main(string[] args) { var mappings = new Dictionary<Tuple<bool, bool>, string> { { new Tuple<bool, bool>(true, true), "- FizzBuzz"}, { new Tuple<bool, bool>(true, false), "- Fizz"}, { new Tuple<bool, bool>(false, true), "- Buzz"}, { new Tuple<bool, bool>(false, false), ""} }; var fizzBuzz = new FizzBuzzCalculator(mappings); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } Console.ReadLine(); } } In my second attempt I looked at removing the if else in the NumberFormat method. A dictionary proved to be useful for this – I added a constructor to the class and injected the dictionary mapping. One could argue that this is totally overkill, but if I was going to use this code in a large system an approach like this makes it easy to put this data in a configuration file, which would up its OC (Open for extensibility, closed for modification principle). I could of course take the OC principle even further – the check for divisibility by 3 and 5 is tightly coupled to this class. If I wanted to make it 4 instead of 3, I would need to adjust this class. This introduces my third refactoring. Solution 3 – Introducing Delegates and Injecting them into the class public delegate bool FizzBuzzComparison(int number); public class FizzBuzzCalculator { private readonly Dictionary<Tuple<bool, bool>, string> _mappings; private readonly FizzBuzzComparison _comparison1; private readonly FizzBuzzComparison _comparison2; public FizzBuzzCalculator(Dictionary<Tuple<bool, bool>, string> mappings, FizzBuzzComparison comparison1, FizzBuzzComparison comparison2) { _mappings = mappings; _comparison1 = comparison1; _comparison2 = comparison2; } public string NumberFormat(int number) { var mappedKey = new Tuple<bool, bool>(_comparison1(number), _comparison2(number)); return String.Format("{0} {1}", number, _mappings[mappedKey]); } } class Program { private static bool DivisibleByNum(int number, int divisor) { return number % divisor == 0; } public static bool Divisibleby3(int number) { return number % 3 == 0; } public static bool Divisibleby5(int number) { return number % 5 == 0; } static void Main(string[] args) { var mappings = new Dictionary<Tuple<bool, bool>, string> { { new Tuple<bool, bool>(true, true), "- FizzBuzz"}, { new Tuple<bool, bool>(true, false), "- Fizz"}, { new Tuple<bool, bool>(false, true), "- Buzz"}, { new Tuple<bool, bool>(false, false), ""} }; var fizzBuzz = new FizzBuzzCalculator(mappings, Divisibleby3, Divisibleby5); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } Console.ReadLine(); } } I have taken this one step further and introduced delegates that are injected into the FizzBuzz Calculator class, from an OC principle perspective it has probably made it more compliant than the previous Solution 2, but there seems to be a lot of noise. Anonymous Delegates increase the readability level, which is what I have done in Solution 4. Solution 4 – Anon Delegates public delegate bool FizzBuzzComparison(int number); public class FizzBuzzCalculator { private readonly Dictionary<Tuple<bool, bool>, string> _mappings; private readonly FizzBuzzComparison _comparison1; private readonly FizzBuzzComparison _comparison2; public FizzBuzzCalculator(Dictionary<Tuple<bool, bool>, string> mappings, FizzBuzzComparison comparison1, FizzBuzzComparison comparison2) { _mappings = mappings; _comparison1 = comparison1; _comparison2 = comparison2; } public string NumberFormat(int number) { var mappedKey = new Tuple<bool, bool>(_comparison1(number), _comparison2(number)); return String.Format("{0} {1}", number, _mappings[mappedKey]); } } class Program { static void Main(string[] args) { var mappings = new Dictionary<Tuple<bool, bool>, string> { { new Tuple<bool, bool>(true, true), "- FizzBuzz"}, { new Tuple<bool, bool>(true, false), "- Fizz"}, { new Tuple<bool, bool>(false, true), "- Buzz"}, { new Tuple<bool, bool>(false, false), ""} }; var fizzBuzz = new FizzBuzzCalculator(mappings, (n) => n % 3 == 0, (n) => n % 5 == 0); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } Console.ReadLine(); } }   Using the anonymous delegates I think the noise level has now been reduced. This is where I am going to end this post, I have gone through 4 iterations of the code from the initial solution using If..Else to delegates and dictionaries. I think each approach would have it’s pro’s and con’s and depending on the intention of where the code would be used would be a large determining factor. If you can think of an alternative way to do FizzBuzz, add a comment!

  Read the article

• Chrome and Firefox not able to find some sites after Ubuntu's recent update?

  - by gkr

  Loading of revision3.com in Chrome stops and status saying "waiting for static.inplay.tubemogul.com" grooveshark.com in Chrome never loads But wikipedia.org, google.com works just normal same behavior in Firefox too. I use wired DSL connection in Ubuntu 12.04. I guess this started happening after I upgraded the Chrome browser or Flash plugin few days ago from Ubuntu updates through update-manager. Thanks EDIT: Everything works normal in my WinXP. Problem is only in Ubuntu 12.04. This is what I get when I use wget gkr@gkr-desktop:~$ wget revision3.com --2012-06-12 08:58:01-- http://revision3.com/ Resolving revision3.com (revision3.com)... 173.192.117.198 Connecting to revision3.com (revision3.com)|173.192.117.198|:80... connected. HTTP request sent, awaiting response... 200 OK Length: unspecified [text/html] Saving to: `index.html' [ ] 81,046 32.0K/s in 2.5s 2012-06-12 08:58:04 (32.0 KB/s) - `index.html' saved [81046] gkr@gkr-desktop:~$ wget static.inplay.tubemogul.com --2012-06-12 08:51:25-- http://static.inplay.tubemogul.com/ Resolving static.inplay.tubemogul.com (static.inplay.tubemogul.com)... 72.21.81.253 Connecting to static.inplay.tubemogul.com (static.inplay.tubemogul.com)|72.21.81.253|:80... connected. HTTP request sent, awaiting response... 404 Not Found 2012-06-12 08:51:25 ERROR 404: Not Found. grooveshark.com nevers responses so I have to Ctrl+C to terminate wget. gkr@gkr-desktop:~$ wget grooveshark.com --2012-06-12 08:51:33-- http://grooveshark.com/ Resolving grooveshark.com (grooveshark.com)... 8.20.213.76 Connecting to grooveshark.com (grooveshark.com)|8.20.213.76|:80... connected. HTTP request sent, awaiting response... ^C gkr@gkr-desktop:~$ This is the apt term.log of updates I mentioned Log started: 2012-06-09 04:51:45 (Reading database ... (Reading database ... 5% (Reading database ... 10% (Reading database ... 15% (Reading database ... 20% (Reading database ... 25% (Reading database ... 30% (Reading database ... 35% (Reading database ... 40% (Reading database ... 45% (Reading database ... 50% (Reading database ... 55% (Reading database ... 60% (Reading database ... 65% (Reading database ... 70% (Reading database ... 75% (Reading database ... 80% (Reading database ... 85% (Reading database ... 90% (Reading database ... 95% (Reading database ... 100% (Reading database ... 161392 files and directories currently installed.) Preparing to replace google-chrome-stable 19.0.1084.52-r138391 (using .../google-chrome-stable_19.0.1084.56-r140965_i386.deb) ... Unpacking replacement google-chrome-stable ... Preparing to replace libpulse0 1:1.1-0ubuntu15 (using .../libpulse0_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement libpulse0 ... Preparing to replace libpulse-mainloop-glib0 1:1.1-0ubuntu15 (using .../libpulse-mainloop-glib0_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement libpulse-mainloop-glib0 ... Preparing to replace libpulsedsp 1:1.1-0ubuntu15 (using .../libpulsedsp_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement libpulsedsp ... Preparing to replace sudo 1.8.3p1-1ubuntu3.2 (using .../sudo_1.8.3p1-1ubuntu3.3_i386.deb) ... Unpacking replacement sudo ... Preparing to replace flashplugin-installer 11.2.202.235ubuntu0.12.04.1 (using .../flashplugin-installer_11.2.202.236ubuntu0.12.04.1_i386.deb) ... Unpacking replacement flashplugin-installer ... Preparing to replace pulseaudio-utils 1:1.1-0ubuntu15 (using .../pulseaudio-utils_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement pulseaudio-utils ... Preparing to replace pulseaudio 1:1.1-0ubuntu15 (using .../pulseaudio_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement pulseaudio ... Preparing to replace pulseaudio-module-gconf 1:1.1-0ubuntu15 (using .../pulseaudio-module-gconf_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement pulseaudio-module-gconf ... Preparing to replace pulseaudio-module-x11 1:1.1-0ubuntu15 (using .../pulseaudio-module-x11_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement pulseaudio-module-x11 ... Preparing to replace shared-mime-info 1.0-0ubuntu4 (using .../shared-mime-info_1.0-0ubuntu4.1_i386.deb) ... Unpacking replacement shared-mime-info ... Preparing to replace pulseaudio-module-bluetooth 1:1.1-0ubuntu15 (using .../pulseaudio-module-bluetooth_1%3a1.1-0ubuntu15.1_i386.deb) ... Unpacking replacement pulseaudio-module-bluetooth ... Processing triggers for menu ... /usr/share/menu/downverter.menu: 1: /usr/share/menu/downverter.menu: Syntax error: word unexpected (expecting ")") Processing triggers for man-db ... locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory Processing triggers for bamfdaemon ... Rebuilding /usr/share/applications/bamf.index... Processing triggers for desktop-file-utils ... Processing triggers for gnome-menus ... Processing triggers for ureadahead ... ureadahead will be reprofiled on next reboot Processing triggers for update-notifier-common ... flashplugin-installer: downloading http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_11.2.202.236.orig.tar.gz Installing from local file /tmp/tmpNrBt4g.gz Flash Plugin installed. Processing triggers for doc-base ... Processing 1 changed doc-base file... Registering documents with scrollkeeper... Setting up google-chrome-stable (19.0.1084.56-r140965) ... Setting up libpulse0 (1:1.1-0ubuntu15.1) ... Setting up libpulse-mainloop-glib0 (1:1.1-0ubuntu15.1) ... Setting up libpulsedsp (1:1.1-0ubuntu15.1) ... Setting up sudo (1.8.3p1-1ubuntu3.3) ... Installing new version of config file /etc/pam.d/sudo ... Setting up flashplugin-installer (11.2.202.236ubuntu0.12.04.1) ... locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_MESSAGES to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory Setting up pulseaudio-utils (1:1.1-0ubuntu15.1) ... Setting up pulseaudio (1:1.1-0ubuntu15.1) ... Setting up pulseaudio-module-gconf (1:1.1-0ubuntu15.1) ... Setting up pulseaudio-module-x11 (1:1.1-0ubuntu15.1) ... Setting up shared-mime-info (1.0-0ubuntu4.1) ... Setting up pulseaudio-module-bluetooth (1:1.1-0ubuntu15.1) ... Processing triggers for menu ... /usr/share/menu/downverter.menu: 1: /usr/share/menu/downverter.menu: Syntax error: word unexpected (expecting ")") Processing triggers for libc-bin ... ldconfig deferred processing now taking place Log ended: 2012-06-09 04:53:32 This is from history.log Start-Date: 2012-06-09 04:51:45 Commandline: aptdaemon role='role-commit-packages' sender=':1.56' Upgrade: shared-mime-info:i386 (1.0-0ubuntu4, 1.0-0ubuntu4.1), pulseaudio:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), libpulse-mainloop-glib0:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), sudo:i386 (1.8.3p1-1ubuntu3.2, 1.8.3p1-1ubuntu3.3), pulseaudio-module-bluetooth:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), pulseaudio-module-x11:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), flashplugin-installer:i386 (11.2.202.235ubuntu0.12.04.1, 11.2.202.236ubuntu0.12.04.1), pulseaudio-utils:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), pulseaudio-module-gconf:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), libpulse0:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), libpulsedsp:i386 (1.1-0ubuntu15, 1.1-0ubuntu15.1), google-chrome-stable:i386 (19.0.1084.52-r138391, 19.0.1084.56-r140965) End-Date: 2012-06-09 04:53:32

  Read the article

• Hosting and consuming WCF services without configuration files

  - by martinsj

  In this post, I'll demonstrate how to configure both the host and the client in code without the need for configuring services i the <system.serviceModel> section of the config-file. In fact, you don't need a  <system.serviceModel> section at all. What you'll do need (and want) sometimes, is the Uri of the service in the configuration file. Configuring the Uri of the the service is actually only needed for the client or when self-hosting, not when hosting in IIS. So, exactly What do we need to configure? The binding type and the binding constraints The metadata behavior Debug behavior You can of course configure even more, and even more if you want to, WCF is after all the king of configuration… As an example I'll be hosting and consuming a service that removes most of the default constraints for WCF-services, using a BasicHttpBinding. Of course, in regards to security, it is probably better to have some constraints on the server, but this is only a demonstration. The ServerConfig class in the code beneath is a static helper class that will be used in the examples. In this post, I’ll be using this helper-class for all configuration, for both the server and the client. In WCF, the  client and the server have both their own WCF-configuration. With this piece of code, they will be sharing the same configuration. 1: public static class ServiceConfig 2: { 3: public static Binding DefaultBinding 4: { 5: get 6: { 7: var binding = new BasicHttpBinding(); 8: Configure(binding); 9: return binding; 10: } 11: } 12:  13: public static void Configure(HttpBindingBase binding) 14: { 15: if (binding == null) 16: { 17: throw new ArgumentException("Argument 'binding' cannot be null. Cannot configure binding."); 18: } 19:  20: binding.SendTimeout = new TimeSpan(0, 0, 30, 0); // 30 minute timeout 21: binding.MaxBufferSize = Int32.MaxValue; 22: binding.MaxBufferPoolSize = 2147483647; 23: binding.MaxReceivedMessageSize = Int32.MaxValue; 24: binding.ReaderQuotas.MaxArrayLength = Int32.MaxValue; 25: binding.ReaderQuotas.MaxBytesPerRead = Int32.MaxValue; 26: binding.ReaderQuotas.MaxDepth = Int32.MaxValue; 27: binding.ReaderQuotas.MaxNameTableCharCount = Int32.MaxValue; 28: binding.ReaderQuotas.MaxStringContentLength = Int32.MaxValue; 29: } 30:  31: public static ServiceMetadataBehavior ServiceMetadataBehavior 32: { 33: get 34: { 35: return new ServiceMetadataBehavior 36: { 37: HttpGetEnabled = true, 38: MetadataExporter = {PolicyVersion = PolicyVersion.Policy15} 39: }; 40: } 41: } 42:  43: public static ServiceDebugBehavior ServiceDebugBehavior 44: { 45: get 46: { 47: var smb = new ServiceDebugBehavior(); 48: Configure(smb); 49: return smb; 50: } 51: } 52:  53:  54: public static void Configure(ServiceDebugBehavior behavior) 55: { 56: if (behavior == null) 57: { 58: throw new ArgumentException("Argument 'behavior' cannot be null. Cannot configure debug behavior."); 59: } 60: 61: behavior.IncludeExceptionDetailInFaults = true; 62: } 63: } Configuring the server There are basically two ways to host a WCF service, in IIS and self-hosting. When hosting a WCF service in a production environment using SOA architecture, you'll be most likely hosting it in IIS. When testing the service in integration tests, it's very handy to be able to self-host services in the unit-tests. In fact, you can share the the WCF configuration for self-hosted services and services hosted in IIS. And that is exactly what you want to do, testing the same configurations for test and production environments.   Configuring when Self-hosting When self-hosting, in order to start the service, you'll have to instantiate the ServiceHost class, configure the  service and open it. 1: // Create the service-host. 2: var host = new ServiceHost(typeof(MyService), endpoint); 3:  4: // Configure the binding 5: host.AddServiceEndpoint(typeof(IMyService), ServiceConfig.DefaultBinding, endpoint); 6:  7: // Configure metadata behavior 8: host.Description.Behaviors.Add(ServiceConfig.ServiceMetadataBehavior); 9:  10: // Configure debgug behavior 11: ServiceConfig.Configure((ServiceDebugBehavior)host.Description.Behaviors[typeof(ServiceDebugBehavior)]); 12: 13: // Start listening to the service 14: host.Open(); 15:  Configuring when hosting in IIS When you create a WCF service application with the wizard in Visual Studio, you'll end up with bits and pieces of code in order to get the service running: Svc-file with codebehind. A interface to the service Web.config In order to get rid of the configuration in the <system.serviceModel> section, which the wizard has generated for us, we must tell the service that we have a factory that will create the service for us. We do this by changing the markup for the svc-file: 1: <%@ ServiceHost Language="C#" Debug="true" Service="Namespace.MyService" Factory="Namespace.ServiceHostFactory" %> The markup tells IIS that we have a factory called ServiceHostFactory for this service. The service factory has a method we can override which will be called when someone asks IIS for the service. There are overloads we can override: 1: System.ServiceModel.ServiceHostBase CreateServiceHost(string constructorString, Uri[] baseAddresses) 2: System.ServiceModel.ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses) 3:  In this example, we'll be using the last one, so our implementation looks like this: 1: public class ServiceHostFactory : System.ServiceModel.Activation.ServiceHostFactory 2: { 3:  4: protected override System.ServiceModel.ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses) 5: { 6: var host = base.CreateServiceHost(serviceType, baseAddresses); 7: host.Description.Behaviors.Add(ServiceConfig.ServiceMetadataBehavior); 8: ServiceConfig.Configure((ServiceDebugBehavior)host.Description.Behaviors[typeof(ServiceDebugBehavior)]); 9: return host; 10: } 11: } 12:  1: public class ServiceHostFactory : System.ServiceModel.Activation.ServiceHostFactory 2: { 3: 4: protected override System.ServiceModel.ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses) 5: { 6: var host = base.CreateServiceHost(serviceType, baseAddresses); 7: host.Description.Behaviors.Add(ServiceConfig.ServiceMetadataBehavior); 8: ServiceConfig.Configure((ServiceDebugBehavior)host.Description.Behaviors[typeof(ServiceDebugBehavior)]); 9: return host; 10: } 11: } 12: As you can see, we are using the same configuration helper we used when self-hosting. Now, when you have a factory, the <system.serviceModel> section of the configuration can be removed, because the section will be ignored when the service has a custom factory. If you want to configure something else in the config-file, one could configure in some other section.   Configuring the client Microsoft has helpfully created a ChannelFactory class in order to create a proxy client. When using this approach, you don't have generate those awfull proxy classes for the client. If you share the contracts with the server in it's own assembly like in the layer diagram under, you can share the same piece of code. The contracts in WCF are the interface to the service and if any, the datacontracts (custom types) the service depends on. Using the ChannelFactory with our configuration helper-class is very simple: 1: var identity = EndpointIdentity.CreateDnsIdentity("localhost"); 2: var endpointAddress = new EndpointAddress(endPoint, identity); 3: var factory = new ChannelFactory<IMyService>(DeployServiceConfig.DefaultBinding, endpointAddress); 4: using (var myService = new factory.CreateChannel()) 5: { 6: myService.Hello(); 7: } 8: factory.Close();   Happy configuration!

  Read the article

• Lambda&rsquo;s for .NET made easy&hellip;

  - by mbcrump

  The purpose of my blog is to explain things for a beginner to intermediate c# programmer. I’ve seen several blog post that use lambda expressions always assuming the audience is familiar with them. The purpose of this post is to make them simple and easily understood. Let’s begin with a definition. A lambda expression is an anonymous function that can contain expressions and statements, and can be used to create delegates or expression tree types. So anonymous function… delegates or expression tree types? I don’t get it??? Confused yet?   Lets break this into a few definitions and jump right into the code. anonymous function – is an "inline" statement or expression that can be used wherever a delegate type is expected. delegate - is a type that references a method. Once a delegate is assigned a method, it behaves exactly like that method. The delegate method can be used like any other method, with parameters and a return value. Expression trees - represent code in a tree-like data structure, where each node is an expression, for example, a method call or a binary operation such as x < y.   Don’t worry if this still sounds confusing, lets jump right into the code with a simple 3 line program. We are going to use a Function Delegate (all you need to remember is that this delegate returns a value.) Lambda expressions are used most commonly with the Func and Action delegates, so you will see an example of both of these. Lambda Expression 3 lines. using System; using System.Collections.Generic; using System.Linq; using System.Text;   namespace ConsoleApplication7 {     class Program     {          static void Main(string[] args)         {             Func<int, int> myfunc = x => x *x;             Console.WriteLine(myfunc(6).ToString());             Console.ReadLine();         }       } } Is equivalent to Old way of doing it. using System; using System.Collections.Generic; using System.Linq; using System.Text;   namespace ConsoleApplication7 {     class Program     {          static void Main(string[] args)         {               Console.WriteLine(myFunc(6).ToString());             Console.ReadLine();         }            static int myFunc(int x)          {              return x * x;            }       } } In the example, there is a single parameter, x, and the expression is x*x. I’m going to stop here to make sure you are still with me. A lambda expression is an unnamed method written in place of a delegate instance. In other words, the compiler converts the lambda expression to either a : A delegate instance An expression tree All lambda have the following form: (parameters) => expression or statement block Now look back to the ones we have created. It should start to sink in. Don’t get stuck on the => form, use it as an identifier of a lambda. A Lamba expression can also be written in the following form: Lambda Expression. using System; using System.Collections.Generic; using System.Linq; using System.Text;   namespace ConsoleApplication7 {     class Program     {          static void Main(string[] args)         {             Func<int, int> myFunc = x =>             {                 return x * x;             };               Console.WriteLine(myFunc(6).ToString());             Console.ReadLine();         }       } } This form may be easier to read but consumes more space. Lets try an Action delegate – this delegate does not return a value. Action Delegate example. using System; using System.Collections.Generic; using System.Linq; using System.Text;   namespace ConsoleApplication7 {     class Program     {          static void Main(string[] args)         {             Action<string> myAction = (string x) => { Console.WriteLine(x); };             myAction("michael has made this so easy");                                   Console.ReadLine();         }       } } Lambdas can also capture outer variables (such as the example below) A lambda expression can reference the local variables and parameters of the method in which it’s defined. Outer variables referenced by a lambda expression are called captured variables. Capturing Outer Variables using System; using System.Collections.Generic; using System.Linq; using System.Text;   namespace ConsoleApplication7 {     class Program     {          static void Main(string[] args)         {             string mike = "Michael";             Action<string> myAction = (string x) => {                 Console.WriteLine("{0}{1}", mike, x);          };             myAction(" has made this so easy");                                   Console.ReadLine();         }       } } Lamba’s can also with a strongly typed list to loop through a collection.   Used w a strongly typed list. using System; using System.Collections.Generic; using System.Linq; using System.Text;   namespace ConsoleApplication7 {     class Program     {          static void Main(string[] args)         {             List<string> list = new List<string>() { "1", "2", "3", "4" };             list.ForEach(s => Console.WriteLine(s));             Console.ReadLine();         }       } } Outputs: 1 2 3 4 I think this will get you started with Lambda’s, as always consult the MSDN documentation for more information. Still confused? Hopefully you are not.

  Read the article

• Bluetooth connection. Problem with sony ericsson.

  - by Hugi

  I have bt client and server. Then i use method Connector.open, client connects to the port, but passed so that my server does not see them. Nokia for all normal, but with sony ericsson i have this problem. On bt adapter open one port (com 5). Listings Client /* * To change this template, choose Tools | Templates * and open the template in the editor. */ import java.util.Vector; import javax.bluetooth.*; import javax.microedition.midlet.*; import javax.microedition.lcdui.*; import javax.microedition.io.*; import java.io.*; /** * @author ????????????? */ public class Client extends MIDlet implements DiscoveryListener, CommandListener { private static Object lock=new Object(); private static Vector vecDevices=new Vector(); private ServiceRecord[] servRec = new ServiceRecord[INQUIRY_COMPLETED]; private Form form = new Form( "Search" ); private List voteList = new List( "Vote list", List.IMPLICIT ); private List vote = new List( "", List.EXCLUSIVE ); private RemoteDevice remoteDevice; private String connectionURL = null; protected int stopToken = 255; private Command select = null; public void startApp() { //view form Display.getDisplay(this).setCurrent(form); try { //device search print("Starting device inquiry..."); getAgent().startInquiry(DiscoveryAgent.GIAC, this); try { synchronized(lock){ lock.wait(); } }catch (InterruptedException e) { e.printStackTrace(); } //device count int deviceCount=vecDevices.size(); if(deviceCount <= 0) { print("No Devices Found ."); } else{ remoteDevice=(RemoteDevice)vecDevices.elementAt(0); print( "Server found" ); //create uuid UUID uuid = new UUID(0x1101); UUID uuids[] = new UUID[] { uuid }; //search service print( "Searching for service..." ); getAgent().searchServices(null,uuids,remoteDevice,this); } } catch( Exception e) { e.printStackTrace(); } } //if deivce discovered add to vecDevices public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) { //add the device to the vector try { if(!vecDevices.contains(btDevice) && btDevice.getFriendlyName(true).equals("serverHugi")){ vecDevices.addElement(btDevice); } } catch( IOException e ) { } } public synchronized void servicesDiscovered(int transID, ServiceRecord[] servRecord) { //for each service create connection if( servRecord!=null && servRecord.length>0 ){ print( "Service found" ); connectionURL = servRecord[0].getConnectionURL(ServiceRecord.NOAUTHENTICATE_NOENCRYPT,false); //connectionURL = servRecord[0].getConnectionURL(ServiceRecord.AUTHENTICATE_NOENCRYPT,false); } if ( connectionURL != null ) { showVoteList(); } } public void serviceSearchCompleted(int transID, int respCode) { //print( "serviceSearchCompleted" ); synchronized(lock){ lock.notify(); } } //This callback method will be called when the device discovery is completed. public void inquiryCompleted(int discType) { synchronized(lock){ lock.notify(); } switch (discType) { case DiscoveryListener.INQUIRY_COMPLETED : print("INQUIRY_COMPLETED"); break; case DiscoveryListener.INQUIRY_TERMINATED : print("INQUIRY_TERMINATED"); break; case DiscoveryListener.INQUIRY_ERROR : print("INQUIRY_ERROR"); break; default : print("Unknown Response Code"); break; } } //add message at form public void print( String msg ) { form.append( msg ); form.append( "\n\n" ); } public void pauseApp() { } public void destroyApp(boolean unconditional) { } //get agent :))) private DiscoveryAgent getAgent() { try { return LocalDevice.getLocalDevice().getDiscoveryAgent(); } catch (BluetoothStateException e) { throw new Error(e.getMessage()); } } private synchronized String getMessage( final String send ) { StreamConnection stream = null; DataInputStream in = null; DataOutputStream out = null; String r = null; try { //open connection stream = (StreamConnection) Connector.open(connectionURL); in = stream.openDataInputStream(); out = stream.openDataOutputStream(); out.writeUTF( send ); out.flush(); r = in.readUTF(); print( r ); in.close(); out.close(); stream.close(); return r; } catch (IOException e) { } finally { if (stream != null) { try { stream.close(); } catch (IOException e) { } } return r; } } private synchronized void showVoteList() { String votes = getMessage( "c_getVotes" ); voteList.append( votes, null ); select = new Command( "Select", Command.OK, 4 ); voteList.addCommand( select ); voteList.setCommandListener( this ); Display.getDisplay(this).setCurrent(voteList); } private synchronized void showVote( int index ) { String title = getMessage( "c_getVote_"+index ); vote.setTitle( title ); vote.append( "Yes", null ); vote.append( "No", null ); vote.setCommandListener( this ); Display.getDisplay(this).setCurrent(vote); } public void commandAction( Command c, Displayable d ) { if ( c == select && d == voteList ) { int index = voteList.getSelectedIndex(); print( ""+index ); showVote( index ); } } } Use BlueCove in this program. Server /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package javaapplication4; import java.io.*; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; import javax.bluetooth.*; import javax.microedition.io.*; import javaapplication4.Connect; /** * * @author ????????????? */ public class SampleSPPServer { protected static int endToken = 255; private static Lock lock=new ReentrantLock(); private static StreamConnection conn = null; private static StreamConnectionNotifier streamConnNotifier = null; private void startServer() throws IOException{ //Create a UUID for SPP UUID uuid = new UUID("1101", true); //Create the service url String connectionString = "btspp://localhost:" + uuid +";name=Sample SPP Server"; //open server url StreamConnectionNotifier streamConnNotifier = (StreamConnectionNotifier)Connector.open( connectionString ); while ( true ) { Connect ct = new Connect( streamConnNotifier.acceptAndOpen() ); ct.getMessage(); } } /** * @param args the command line arguments */ public static void main(String[] args) { //display local device address and name try { LocalDevice localDevice = LocalDevice.getLocalDevice(); localDevice.setDiscoverable(DiscoveryAgent.GIAC); System.out.println("Name: "+localDevice.getFriendlyName()); } catch( Throwable e ) { e.printStackTrace(); } SampleSPPServer sampleSPPServer=new SampleSPPServer(); try { //start server sampleSPPServer.startServer(); } catch( IOException e ) { e.printStackTrace(); } } } Connect /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package javaapplication4; import java.io.*; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; import javax.bluetooth.*; import javax.microedition.io.*; /** * * @author ????????????? */ public class Connect { private static DataInputStream in = null; private static DataOutputStream out = null; private static StreamConnection connection = null; private static Lock lock=new ReentrantLock(); public Connect( StreamConnection conn ) { connection = conn; } public synchronized void getMessage( ) { Thread t = new Thread() { public void run() { try { in = connection.openDataInputStream(); out = connection.openDataOutputStream(); String r = in.readUTF(); System.out.println("read:" + r); if ( r.equals( "c_getVotes" ) ) { out.writeUTF( "vote1" ); out.flush(); } if ( r.equals( "c_getVote_0" ) ) { out.writeUTF( "Vote1" ); out.flush(); } out.close(); in.close(); } catch (Throwable e) { } finally { if (in != null) { try { in.close(); } catch (IOException e) { } } try { connection.close(); } catch( IOException e ) { } } } }; t.start(); } }

  Read the article

• png image store in database and retrieve in android 1.5

  - by hany

  hai, I am new to android. I have problem. This is my code but it will not work, the problem is in view binder. Please correct it. // this is my activity package com.android.Fruits2; import java.util.ArrayList; import java.util.HashMap; import android.app.ListActivity; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Bundle; import android.widget.SimpleAdapter; import android.widget.SimpleCursorAdapter; import android.widget.SimpleAdapter.ViewBinder; public class Fruits2 extends ListActivity { private DBhelper mDB; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // setContentView(R.layout.main); mDB = new DBhelper(this); mDB.Reset(); Bitmap img = BitmapFactory.decodeResource(getResources(), R.drawable.icon); mDB.createPersonEntry(new PersonData(img, "Harsha", 24,"mca")); String[] columns = {mDB.KEY_ID, mDB.KEY_IMG, mDB.KEY_NAME, mDB.KEY_AGE, mDB.KEY_STUDY}; String table = mDB.PERSON_TABLE; Cursor c = mDB.getHandle().query(table, columns, null, null, null, null, null); startManagingCursor(c); SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.data, c, new String[] {mDB.KEY_IMG, mDB.KEY_NAME, mDB.KEY_AGE, mDB.KEY_STUDY}, new int[] {R.id.img, R.id.name, R.id.age,R.id.study}); adapter.setViewBinder( new MyViewBinder()); setListAdapter(adapter); } } //my viewbinder package com.android.Fruits2; import android.database.Cursor; import android.graphics.BitmapFactory; import android.view.View; import android.widget.ImageView; import android.widget.SimpleCursorAdapter; public class MyViewBinder implements SimpleCursorAdapter.ViewBinder { public boolean setViewValue(View view, Cursor cursor, int columnIndex) { if( (view instanceof ImageView) ) { ImageView iv = (ImageView) view; byte[] img = cursor.getBlob(columnIndex); iv.setImageBitmap(BitmapFactory.decodeByteArray(img, 0, img.length)); return true; } return false; } } // data package com.android.Fruits2; import android.graphics.Bitmap; public class PersonData { private Bitmap bmp; private String name; private int age; private String study; public PersonData(Bitmap b, String n, int k, String v) { bmp = b; name = n; age = k; study = v; } public Bitmap getBitmap() { return bmp; } public String getName() { return name; } public int getAge() { return age; } public String getStudy() { return study; } } //dbhelper package com.android.Fruits2; import java.io.ByteArrayOutputStream; import android.content.ContentValues; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.graphics.Bitmap; import android.provider.BaseColumns; public class DBhelper { public static final String KEY_ID = BaseColumns._ID; public static final String KEY_NAME = "name"; public static final String KEY_AGE = "age"; public static final String KEY_STUDY = "study"; public static final String KEY_IMG = "image"; private DatabaseHelper mDbHelper; private SQLiteDatabase mDb; private static final String DATABASE_NAME = "PersonalDB"; private static final int DATABASE_VERSION = 1; public static final String PERSON_TABLE = "Person"; private static final String CREATE_PERSON_TABLE = "create table "+PERSON_TABLE+" (" +KEY_ID+" integer primary key autoincrement, " +KEY_IMG+" blob not null, " +KEY_NAME+" text not null , " +KEY_AGE+" integer not null, " +KEY_STUDY+" text not null);"; private final Context mCtx; private boolean opened = false; private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_PERSON_TABLE); } public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { db.execSQL("DROP TABLE IF EXISTS "+PERSON_TABLE); onCreate(db); } } public void Reset() { openDB(); mDbHelper.onUpgrade(this.mDb, 1, 1); closeDB(); } public DBhelper(Context ctx) { mCtx = ctx; mDbHelper = new DatabaseHelper(mCtx); } private SQLiteDatabase openDB() { if(!opened) mDb = mDbHelper.getWritableDatabase(); opened = true; return mDb; } public SQLiteDatabase getHandle() { return openDB(); } private void closeDB() { if(opened) mDbHelper.close(); opened = false; } public void createPersonEntry(PersonData about) { openDB(); ByteArrayOutputStream out = new ByteArrayOutputStream(); about.getBitmap().compress(Bitmap.CompressFormat.PNG, 100, out); ContentValues cv = new ContentValues(); cv.put(KEY_IMG, out.toByteArray()); cv.put(KEY_NAME, about.getName()); cv.put(KEY_AGE, about.getAge()); cv.put(KEY_STUDY, about.getStudy()); mDb.insert(PERSON_TABLE, null, cv); closeDB(); } } //data.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content"> <ImageView android:id = "@+id/img" android:layout_width = "wrap_content" android:layout_height = "wrap_content" > </ImageView> <TextView android:id = "@+id/name" android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:textSize="15dp" android:textColor="#ff0000" > </TextView> <TextView android:id = "@+id/age" android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:textSize="15dp" android:textColor="#ff0000" /> <TextView android:id = "@+id/study" android:layout_width = "wrap_content" android:layout_height = "wrap_content" android:textSize="15dp" android:textColor="#ff0000" /> </LinearLayout> When I run this in android 1.6 and 2.1, it works. But when I run in android 1.5, not work. My application is android 1.5. Please correct and send code to me. Thank you.

  Read the article

• how to version minder for web application data

  - by dankyy1

  hi all;I'm devoloping a web application which renders data from DB and also updates datas with editor UI Pages.So i want to implement a versioning mechanism for render pages got data over db again if only data on db updated by editor pages.. I decided to use Session objects for the version information that client had taken latestly.And the Application object that the latest DB version of objects ,i used the data objects guid as key for each data item client version holder class like below ItemRunnigVersionInformation class holds currentitem guid and last loadtime from DB public class ClientVersionManager { public static List<ItemRunnigVersionInformation> SessionItemRunnigVersionInformation { get { if (HttpContext.Current.Session["SessionItemRunnigVersionInformation"] == null) HttpContext.Current.Session["SessionItemRunnigVersionInformation"] = new List<ItemRunnigVersionInformation>(); return (List<ItemRunnigVersionInformation>)HttpContext.Current.Session["SessionItemRunnigVersionInformation"]; } set { HttpContext.Current.Session["SessionItemRunnigVersionInformation"] = value; } } /// <summary> /// this will be updated when editor pages /// </summary> /// <param name="itemRunnigVersionInformation"></param> public static void UpdateItemRunnigSessionVersion(string itemGuid) { ItemRunnigVersionInformation itemRunnigVersionAtAppDomain = PlayListVersionManager.GetItemRunnigVersionInformationByID(itemGuid); ItemRunnigVersionInformation itemRunnigVersionInformationAtSession = SessionItemRunnigVersionInformation.FirstOrDefault(t => t.ItemGuid == itemGuid); if ((itemRunnigVersionInformationAtSession == null) && (itemRunnigVersionAtAppDomain != null)) { ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Add(SessionItemRunnigVersionInformation, itemRunnigVersionAtAppDomain); } else if (itemRunnigVersionAtAppDomain != null) { ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Remove(SessionItemRunnigVersionInformation, itemRunnigVersionInformationAtSession); ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Add(SessionItemRunnigVersionInformation, itemRunnigVersionAtAppDomain); } } /// <summary> /// by given parameters check versions over PlayListVersionManager versions and /// adds versions to clientversion manager if any item version on /// playlist not found it will also added to PlaylistManager list /// </summary> /// <param name="playList"></param> /// <param name="userGuid"></param> /// <param name="ownerGuid"></param> public static void UpdateCurrentSessionVersion(PlayList playList, string userGuid, string ownerGuid) { ItemRunnigVersionInformation tmpItemRunnigVersionInformation; List<ItemRunnigVersionInformation> currentItemRunnigVersionInformationList = new List<ItemRunnigVersionInformation>(); if (!string.IsNullOrEmpty(userGuid)) { tmpItemRunnigVersionInformation = PlayListVersionManager.GetItemRunnigVersionInformationByID(userGuid); if (tmpItemRunnigVersionInformation == null) { tmpItemRunnigVersionInformation = new ItemRunnigVersionInformation(userGuid, DateTime.Now.ToUniversalTime()); PlayListVersionManager.UpdateItemRunnigAppDomainVersion(tmpItemRunnigVersionInformation); } ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Add(currentItemRunnigVersionInformationList, tmpItemRunnigVersionInformation); } if (!string.IsNullOrEmpty(ownerGuid)) { tmpItemRunnigVersionInformation = PlayListVersionManager.GetItemRunnigVersionInformationByID(ownerGuid); if (tmpItemRunnigVersionInformation == null) { tmpItemRunnigVersionInformation = new ItemRunnigVersionInformation(ownerGuid, DateTime.Now.ToUniversalTime()); PlayListVersionManager.UpdateItemRunnigAppDomainVersion(tmpItemRunnigVersionInformation); } ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Add(currentItemRunnigVersionInformationList, tmpItemRunnigVersionInformation); } if ((playList != null) && (playList.PlayListItemCollection != null)) { tmpItemRunnigVersionInformation = PlayListVersionManager.GetItemRunnigVersionInformationByID(playList.GUID); if (tmpItemRunnigVersionInformation == null) { tmpItemRunnigVersionInformation = new ItemRunnigVersionInformation(playList.GUID, DateTime.Now.ToUniversalTime()); PlayListVersionManager.UpdateItemRunnigAppDomainVersion(tmpItemRunnigVersionInformation); } currentItemRunnigVersionInformationList.Add(tmpItemRunnigVersionInformation); foreach (PlayListItem playListItem in playList.PlayListItemCollection) { tmpItemRunnigVersionInformation = PlayListVersionManager.GetItemRunnigVersionInformationByID(playListItem.GUID); if (tmpItemRunnigVersionInformation == null) { tmpItemRunnigVersionInformation = new ItemRunnigVersionInformation(playListItem.GUID, DateTime.Now.ToUniversalTime()); PlayListVersionManager.UpdateItemRunnigAppDomainVersion(tmpItemRunnigVersionInformation); } currentItemRunnigVersionInformationList.Add(tmpItemRunnigVersionInformation); foreach (SoftKey softKey in playListItem.PlayListSoftKeys) { tmpItemRunnigVersionInformation = PlayListVersionManager.GetItemRunnigVersionInformationByID(softKey.GUID); if (tmpItemRunnigVersionInformation == null) { tmpItemRunnigVersionInformation = new ItemRunnigVersionInformation(softKey.GUID, DateTime.Now.ToUniversalTime()); PlayListVersionManager.UpdateItemRunnigAppDomainVersion(tmpItemRunnigVersionInformation); } ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Add(currentItemRunnigVersionInformationList, tmpItemRunnigVersionInformation); } foreach (MenuItem menuItem in playListItem.MenuItems) { tmpItemRunnigVersionInformation = PlayListVersionManager.GetItemRunnigVersionInformationByID(menuItem.Guid); if (tmpItemRunnigVersionInformation == null) { tmpItemRunnigVersionInformation = new ItemRunnigVersionInformation(menuItem.Guid, DateTime.Now.ToUniversalTime()); PlayListVersionManager.UpdateItemRunnigAppDomainVersion(tmpItemRunnigVersionInformation); } ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Add(currentItemRunnigVersionInformationList, tmpItemRunnigVersionInformation); } } } SessionItemRunnigVersionInformation = currentItemRunnigVersionInformationList; } public static ItemRunnigVersionInformation GetItemRunnigVersionInformationById(string itemGuid) { return SessionItemRunnigVersionInformation.FirstOrDefault(t => t.ItemGuid == itemGuid); } public static void DeleteItemRunnigAppDomain(string itemGuid) { ExtensionMethodsForClientVersionManager.ExtensionMethodsForClientVersionManager.Remove(SessionItemRunnigVersionInformation, NG.IPTOffice.Paloma.Helper.ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.GetMatchingItemRunnigVersionInformation(SessionItemRunnigVersionInformation, itemGuid)); } } and that was for server one public class PlayListVersionManager { public static List<ItemRunnigVersionInformation> AppDomainItemRunnigVersionInformation { get { if (HttpContext.Current.Application["AppDomainItemRunnigVersionInformation"] == null) HttpContext.Current.Application["AppDomainItemRunnigVersionInformation"] = new List<ItemRunnigVersionInformation>(); return (List<ItemRunnigVersionInformation>)HttpContext.Current.Application["AppDomainItemRunnigVersionInformation"]; } set { HttpContext.Current.Application["AppDomainItemRunnigVersionInformation"] = value; } } public static ItemRunnigVersionInformation GetItemRunnigVersionInformationByID(string itemGuid) { return ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.GetMatchingItemRunnigVersionInformation(AppDomainItemRunnigVersionInformation, itemGuid); } /// <summary> /// this will be updated when editor pages /// if any record at playlistversion is found it will be addedd /// </summary> /// <param name="itemRunnigVersionInformation"></param> public static void UpdateItemRunnigAppDomainVersion(ItemRunnigVersionInformation itemRunnigVersionInformation) { ItemRunnigVersionInformation itemRunnigVersionInformationAtAppDomain = NG.IPTOffice.Paloma.Helper.ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.GetMatchingItemRunnigVersionInformation(AppDomainItemRunnigVersionInformation, itemRunnigVersionInformation.ItemGuid); if (itemRunnigVersionInformationAtAppDomain == null) { ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.Add(AppDomainItemRunnigVersionInformation, itemRunnigVersionInformation); } else { ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.Remove(AppDomainItemRunnigVersionInformation, itemRunnigVersionInformationAtAppDomain); ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.Add(AppDomainItemRunnigVersionInformation, itemRunnigVersionInformation); } } //this will be checked each time if needed to update item over DB public static bool IsRunnigItemLastVersion(ItemRunnigVersionInformation itemRunnigVersionInformation, bool ignoreNullEntry, out bool itemNotExistsAtAppDomain) { itemNotExistsAtAppDomain = false; if (itemRunnigVersionInformation != null) { ItemRunnigVersionInformation itemRunnigVersionInformationAtAppDomain = AppDomainItemRunnigVersionInformation.FirstOrDefault(t => t.ItemGuid == itemRunnigVersionInformation.ItemGuid); itemNotExistsAtAppDomain = (itemRunnigVersionInformationAtAppDomain == null); if (itemNotExistsAtAppDomain && (ignoreNullEntry)) { ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.Add(AppDomainItemRunnigVersionInformation, itemRunnigVersionInformation); return true; } else if (!itemNotExistsAtAppDomain && (itemRunnigVersionInformationAtAppDomain.LastLoadTime <= itemRunnigVersionInformation.LastLoadTime)) return true; else return false; } else return ignoreNullEntry; } public static void DeleteItemRunnigAppDomain(string itemGuid) { ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.Remove(AppDomainItemRunnigVersionInformation, NG.IPTOffice.Paloma.Helper.ExtensionMethodsFoPlayListVersionManager.ExtensionMethodsFoPlayListVersionManager.GetMatchingItemRunnigVersionInformation(AppDomainItemRunnigVersionInformation, itemGuid)); } } when more than one client requests the page i got "Collection was modified; enumeration operation may not execute." like below.. xception: System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.InvalidOperationException: Collection was modified; enumeration operation may not execute. at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource) at System.Collections.Generic.List1.Enumerator.MoveNextRare() at System.Collections.Generic.List1.Enumerator.MoveNext() at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable1 source, Func2 predicate) at NG.IPTOffice.Paloma.Helper.PlayListVersionManager.UpdateItemRunnigAppDomainVersion(ItemRunnigVersionInformation itemRunnigVersionInformation) in at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace --- at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.playlistwebform_aspx.ProcessRequest(HttpContext context) in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\ipservicestest\8921e5c8\5d09c94d\App_Web_n4qdnfcq.2.cs:line 0 at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)----------- how to implement version management like this scnerio? how can i to avoid this exception? thnx

  Read the article

• How to correctly populate records from SQLlite in ListActivity?

  - by Pavel

  Hi. Can someone please tell me how can I easily display every record from sqllite in ListActivity tab? I'm kinda confused with this. Do I have to create db from my helper class in TabActivity or ListActivity or both? My db helper class is as follow: package tabs.app; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; public class DBAdapter { private static String DB_PATH = "/data/data/tabs.app/databases/"; public static final String KEY_ROWID = "_id"; public static final String KEY_LATITUDE = "latitude"; public static final String KEY_LONGITUDE = "longitude"; private static final String TAG = "DBAdapter"; private static final String DATABASE_NAME = "coords"; private static final String DATABASE_TABLE = "coordsStorages"; private static final int DATABASE_VERSION = 2; /* private static final String DATABASE_CREATE = "create table coordsStorage (_id integer primary key autoincrement, latitude integer not null, longitude integer not null)"; */ public Context context; private DatabaseHelper DBHelper; private SQLiteDatabase db; public DBAdapter(Context ctx) { this.context = ctx; DBHelper = new DatabaseHelper(context); } private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("create table coordsStorages (_id integer primary key autoincrement, latitude integer not null, longitude integer not null)"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS titles"); onCreate(db); } } //---opens the database--- public DBAdapter open() throws SQLException { db = DBHelper.getWritableDatabase(); return this; } //---closes the database--- public void close() { DBHelper.close(); } //---insert a title into the database--- public long insertCoords(int latitude, int longitude) { ContentValues initialValues = new ContentValues(); initialValues.put(KEY_LATITUDE, latitude); initialValues.put(KEY_LONGITUDE, longitude); return db.insert(DATABASE_TABLE, null, initialValues); } public void openDataBase() throws SQLException{ //Open the database String myPath = DB_PATH + DATABASE_NAME; db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); } //---deletes a particular title--- public boolean deleteTitle(long rowId) { return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0; } //---retrieves all the titles--- public Cursor getAllTitles() { return db.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_LATITUDE, KEY_LONGITUDE}, null, null, null, null, null); } //---retrieves a particular title--- public Cursor getTitle(long rowId) throws SQLException { Cursor mCursor = db.query(true, DATABASE_TABLE, new String[] { KEY_ROWID, KEY_LATITUDE, KEY_LONGITUDE}, KEY_ROWID + "=" + rowId, null, null, null, null, null); if (mCursor != null) { mCursor.moveToFirst(); } return mCursor; } //---updates a title--- /*public boolean updateTitle(long rowId, int latitude, int longitude) { ContentValues args = new ContentValues(); args.put(KEY_LATITUDE, latitude); args.put(KEY_LONGITUDE, longitude); return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0; }*/ } And Im trying to retrieve the records in TabActivity like this: public class Areas extends ListActivity { DBAdapter db; SimpleCursorAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.areas_layout); db = new DBAdapter(this); db.open(); Cursor c = db.getAllTitles(); startManagingCursor(c); String[] display = new String[] { db.KEY_LATITUDE }; int[] to = new int[] { R.id.row_latitude}; /* String[] display2 = new String[] { db.KEY_LONGITUDE }; int[] to2 = new int[] { R.id.row_longitude};*/ mAdapter = new SimpleCursorAdapter(this, R.layout.areas_layout, c, display, to); setListAdapter(mAdapter); /* mAdapter2 = new SimpleCursorAdapter(this, R.layout.areas_layout, c, display2, to2); setListAdapter(mAdapter2);*/ db.close(); } /* private void fillData() { // Get all of the rows from the database and create the item list Cursor c = db.getAllTitles(); startManagingCursor(c); }*/ } Whenever I'm trying to do that the error log outputs this: 06-07 09:51:56.529: ERROR/AndroidRuntime(2034): Uncaught handler: thread main exiting due to uncaught exception 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): java.lang.RuntimeException: Unable to start activity ComponentInfo{tabs.app/tabs.app.Areas}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2242) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:631) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.widget.TabHost.setCurrentTab(TabHost.java:317) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:127) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:346) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.View.performClick(View.java:2344) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.View.onTouchEvent(View.java:4133) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.View.dispatchTouchEvent(View.java:3672) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:850) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1712) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1202) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.Activity.dispatchTouchEvent(Activity.java:1987) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1696) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.view.ViewRoot.handleMessage(ViewRoot.java:1658) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.os.Handler.dispatchMessage(Handler.java:99) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.os.Looper.loop(Looper.java:123) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.ActivityThread.main(ActivityThread.java:4203) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at java.lang.reflect.Method.invokeNative(Native Method) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at java.lang.reflect.Method.invoke(Method.java:521) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at dalvik.system.NativeStart.main(Native Method) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.ListActivity.onContentChanged(ListActivity.java:236) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:316) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.Activity.setContentView(Activity.java:1620) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at tabs.app.Areas.onCreate(Areas.java:18) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364) 06-07 09:51:56.559: ERROR/AndroidRuntime(2034): ... 30 more 06-07 09:51:56.619: INFO/Process(51): Sending signal. PID: 2034 SIG: 3 06-07 09:51:56.619: INFO/dalvikvm(2034): threadid=7: reacting to signal 3 06-07 09:51:56.619: ERROR/dalvikvm(2034): Unable to open stack trace file '/data/anr/traces.txt': Permission denied Can someone please tell me what I'm doing wrong? Help greatly appreciated!

  Read the article

• Database Tutorial: The method open() is undefined for the type MainActivity.DBAdapter

  - by user2203633

  I am trying to do this database tutorial on SQLite Eclipse: https://www.youtube.com/watch?v=j-IV87qQ00M But I get a few errors at the end.. at db.ppen(); i get error: The method open() is undefined for the type MainActivity.DBAdapter and similar for insert record and close. MainActivity: package com.example.studentdatabase; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import android.app.Activity; import android.app.ListActivity; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.Toast; public class MainActivity extends Activity { /** Called when the activity is first created. */ //DBAdapter db = new DBAdapter(this); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button addBtn = (Button)findViewById(R.id.add); addBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent i = new Intent(MainActivity.this, addassignment.class); startActivity(i); } }); try { String destPath = "/data/data/" + getPackageName() + "/databases/AssignmentDB"; File f = new File(destPath); if (!f.exists()) { CopyDB( getBaseContext().getAssets().open("mydb"), new FileOutputStream(destPath)); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } DBAdapter db = new DBAdapter(); //---add an assignment--- db.open(); long id = db.insertRecord("Hello World", "2/18/2012", "DPR 224", "First Android Project"); id = db.insertRecord("Workbook Exercises", "3/1/2012", "MAT 100", "Do odd numbers"); db.close(); //---get all Records--- /* db.open(); Cursor c = db.getAllRecords(); if (c.moveToFirst()) { do { DisplayRecord(c); } while (c.moveToNext()); } db.close(); */ /* //---get a Record--- db.open(); Cursor c = db.getRecord(2); if (c.moveToFirst()) DisplayRecord(c); else Toast.makeText(this, "No Assignments found", Toast.LENGTH_LONG).show(); db.close(); */ //---update Record--- /* db.open(); if (db.updateRecord(1, "Hello Android", "2/19/2012", "DPR 224", "First Android Project")) Toast.makeText(this, "Update successful.", Toast.LENGTH_LONG).show(); else Toast.makeText(this, "Update failed.", Toast.LENGTH_LONG).show(); db.close(); */ /* //---delete a Record--- db.open(); if (db.deleteRecord(1)) Toast.makeText(this, "Delete successful.", Toast.LENGTH_LONG).show(); else Toast.makeText(this, "Delete failed.", Toast.LENGTH_LONG).show(); db.close(); */ } private class DBAdapter extends BaseAdapter { private LayoutInflater mInflater; //private ArrayList<> @Override public int getCount() { return 0; } @Override public Object getItem(int arg0) { return null; } @Override public long getItemId(int arg0) { return 0; } @Override public View getView(int arg0, View arg1, ViewGroup arg2) { return null; } } public void CopyDB(InputStream inputStream, OutputStream outputStream) throws IOException { //---copy 1K bytes at a time--- byte[] buffer = new byte[1024]; int length; while ((length = inputStream.read(buffer)) > 0) { outputStream.write(buffer, 0, length); } inputStream.close(); outputStream.close(); } public void DisplayRecord(Cursor c) { Toast.makeText(this, "id: " + c.getString(0) + "\n" + "Title: " + c.getString(1) + "\n" + "Due Date: " + c.getString(2), Toast.LENGTH_SHORT).show(); } public void addAssignment(View view) { Intent i = new Intent("com.pinchtapzoom.addassignment"); startActivity(i); Log.d("TAG", "Clicked"); } } DBAdapter code: package com.example.studentdatabase; public class DBAdapter { public static final String KEY_ROWID = "id"; public static final String KEY_TITLE = "title"; public static final String KEY_DUEDATE = "duedate"; public static final String KEY_COURSE = "course"; public static final String KEY_NOTES = "notes"; private static final String TAG = "DBAdapter"; private static final String DATABASE_NAME = "AssignmentsDB"; private static final String DATABASE_TABLE = "assignments"; private static final int DATABASE_VERSION = 2; private static final String DATABASE_CREATE = "create table if not exists assignments (id integer primary key autoincrement, " + "title VARCHAR not null, duedate date, course VARCHAR, notes VARCHAR );"; private final Context context; private DatabaseHelper DBHelper; private SQLiteDatabase db; public DBAdapter(Context ctx) { this.context = ctx; DBHelper = new DatabaseHelper(context); } private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { try { db.execSQL(DATABASE_CREATE); } catch (SQLException e) { e.printStackTrace(); } } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS contacts"); onCreate(db); } } //---opens the database--- public DBAdapter open() throws SQLException { db = DBHelper.getWritableDatabase(); return this; } //---closes the database--- public void close() { DBHelper.close(); } //---insert a record into the database--- public long insertRecord(String title, String duedate, String course, String notes) { ContentValues initialValues = new ContentValues(); initialValues.put(KEY_TITLE, title); initialValues.put(KEY_DUEDATE, duedate); initialValues.put(KEY_COURSE, course); initialValues.put(KEY_NOTES, notes); return db.insert(DATABASE_TABLE, null, initialValues); } //---deletes a particular record--- public boolean deleteContact(long rowId) { return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0; } //---retrieves all the records--- public Cursor getAllRecords() { return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE, KEY_DUEDATE, KEY_COURSE, KEY_NOTES}, null, null, null, null, null); } //---retrieves a particular record--- public Cursor getRecord(long rowId) throws SQLException { Cursor mCursor = db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE, KEY_DUEDATE, KEY_COURSE, KEY_NOTES}, KEY_ROWID + "=" + rowId, null, null, null, null, null); if (mCursor != null) { mCursor.moveToFirst(); } return mCursor; } //---updates a record--- public boolean updateRecord(long rowId, String title, String duedate, String course, String notes) { ContentValues args = new ContentValues(); args.put(KEY_TITLE, title); args.put(KEY_DUEDATE, duedate); args.put(KEY_COURSE, course); args.put(KEY_NOTES, notes); return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0; } } addassignment code: package com.example.studentdatabase; public class addassignment extends Activity { DBAdapter db = new DBAdapter(this); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.add); } public void addAssignment(View v) { Log.d("test", "adding"); //get data from form EditText nameTxt = (EditText)findViewById(R.id.editTitle); EditText dateTxt = (EditText)findViewById(R.id.editDuedate); EditText courseTxt = (EditText)findViewById(R.id.editCourse); EditText notesTxt = (EditText)findViewById(R.id.editNotes); db.open(); long id = db.insertRecord(nameTxt.getText().toString(), dateTxt.getText().toString(), courseTxt.getText().toString(), notesTxt.getText().toString()); db.close(); nameTxt.setText(""); dateTxt.setText(""); courseTxt.setText(""); notesTxt.setText(""); Toast.makeText(addassignment.this,"Assignment Added", Toast.LENGTH_LONG).show(); } public void viewAssignments(View v) { Intent i = new Intent(this, MainActivity.class); startActivity(i); } } What is wrong here? Thanks in advance.

  Read the article

• Bulk inserting best way to about it? + Helping me understand fully what I found so far

  - by chobo2

  Hi So I saw this post here and read it and it seems like bulk copy might be the way to go. http://stackoverflow.com/questions/682015/whats-the-best-way-to-bulk-database-inserts-from-c I still have some questions and want to know how things actually work. So I found 2 tutorials. http://www.codeproject.com/KB/cs/MultipleInsertsIn1dbTrip.aspx#_Toc196622241 http://www.codeproject.com/KB/linq/BulkOperations_LinqToSQL.aspx First way uses 2 ado.net 2.0 features. BulkInsert and BulkCopy. the second one uses linq to sql and OpenXML. This sort of appeals to me as I am using linq to sql already and prefer it over ado.net. However as one person pointed out in the posts what he just going around the issue at the cost of performance( nothing wrong with that in my opinion) First I will talk about the 2 ways in the first tutorial I am using VS2010 Express, .net 4.0, MVC 2.0, SQl Server 2005 Is ado.net 2.0 the most current version? Based on the technology I am using, is there some updates to what I am going to show that would improve it somehow? Is there any thing that these tutorial left out that I should know about? BulkInsert I am using this table for all the examples. CREATE TABLE [dbo].[TBL_TEST_TEST] ( ID INT IDENTITY(1,1) PRIMARY KEY, [NAME] [varchar](50) ) SP Code USE [Test] GO /****** Object: StoredProcedure [dbo].[sp_BatchInsert] Script Date: 05/19/2010 15:12:47 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE [dbo].[sp_BatchInsert] (@Name VARCHAR(50) ) AS BEGIN INSERT INTO TBL_TEST_TEST VALUES (@Name); END C# Code /// <summary> /// Another ado.net 2.0 way that uses a stored procedure to do a bulk insert. /// Seems slower then "BatchBulkCopy" way and it crashes when you try to insert 500,000 records in one go. /// http://www.codeproject.com/KB/cs/MultipleInsertsIn1dbTrip.aspx#_Toc196622241 /// </summary> private static void BatchInsert() { // Get the DataTable with Rows State as RowState.Added DataTable dtInsertRows = GetDataTable(); SqlConnection connection = new SqlConnection(connectionString); SqlCommand command = new SqlCommand("sp_BatchInsert", connection); command.CommandType = CommandType.StoredProcedure; command.UpdatedRowSource = UpdateRowSource.None; // Set the Parameter with appropriate Source Column Name command.Parameters.Add("@Name", SqlDbType.VarChar, 50, dtInsertRows.Columns[0].ColumnName); SqlDataAdapter adpt = new SqlDataAdapter(); adpt.InsertCommand = command; // Specify the number of records to be Inserted/Updated in one go. Default is 1. adpt.UpdateBatchSize = 1000; connection.Open(); int recordsInserted = adpt.Update(dtInsertRows); connection.Close(); } So first thing is the batch size. Why would you set a batch size to anything but the number of records you are sending? Like I am sending 500,000 records so I did a Batch size of 500,000. Next why does it crash when I do this? If I set it to 1000 for batch size it works just fine. System.Data.SqlClient.SqlException was unhandled Message="A transport-level error has occurred when sending the request to the server. (provider: Shared Memory Provider, error: 0 - No process is on the other end of the pipe.)" Source=".Net SqlClient Data Provider" ErrorCode=-2146232060 Class=20 LineNumber=0 Number=233 Server="" State=0 StackTrace: at System.Data.Common.DbDataAdapter.UpdatedRowStatusErrors(RowUpdatedEventArgs rowUpdatedEvent, BatchCommandInfo[] batchCommands, Int32 commandCount) at System.Data.Common.DbDataAdapter.UpdatedRowStatus(RowUpdatedEventArgs rowUpdatedEvent, BatchCommandInfo[] batchCommands, Int32 commandCount) at System.Data.Common.DbDataAdapter.Update(DataRow[] dataRows, DataTableMapping tableMapping) at System.Data.Common.DbDataAdapter.UpdateFromDataTable(DataTable dataTable, DataTableMapping tableMapping) at System.Data.Common.DbDataAdapter.Update(DataTable dataTable) at TestIQueryable.Program.BatchInsert() in C:\Users\a\Downloads\TestIQueryable\TestIQueryable\TestIQueryable\Program.cs:line 124 at TestIQueryable.Program.Main(String[] args) in C:\Users\a\Downloads\TestIQueryable\TestIQueryable\TestIQueryable\Program.cs:line 16 InnerException: Time it took to insert 500,000 records with insert batch size of 1000 took "2 mins and 54 seconds" Of course this is no official time I sat there with a stop watch( I am sure there are better ways but was too lazy to look what they where) So I find that kinda slow compared to all my other ones(expect the linq to sql insert one) and I am not really sure why. Next I looked at bulkcopy /// <summary> /// An ado.net 2.0 way to mass insert records. This seems to be the fastest. /// http://www.codeproject.com/KB/cs/MultipleInsertsIn1dbTrip.aspx#_Toc196622241 /// </summary> private static void BatchBulkCopy() { // Get the DataTable DataTable dtInsertRows = GetDataTable(); using (SqlBulkCopy sbc = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.KeepIdentity)) { sbc.DestinationTableName = "TBL_TEST_TEST"; // Number of records to be processed in one go sbc.BatchSize = 500000; // Map the Source Column from DataTabel to the Destination Columns in SQL Server 2005 Person Table // sbc.ColumnMappings.Add("ID", "ID"); sbc.ColumnMappings.Add("NAME", "NAME"); // Number of records after which client has to be notified about its status sbc.NotifyAfter = dtInsertRows.Rows.Count; // Event that gets fired when NotifyAfter number of records are processed. sbc.SqlRowsCopied += new SqlRowsCopiedEventHandler(sbc_SqlRowsCopied); // Finally write to server sbc.WriteToServer(dtInsertRows); sbc.Close(); } } This one seemed to go really fast and did not even need a SP( can you use SP with bulk copy? If you can would it be better?) BatchCopy had no problem with a 500,000 batch size.So again why make it smaller then the number of records you want to send? I found that with BatchCopy and 500,000 batch size it took only 5 seconds to complete. I then tried with a batch size of 1,000 and it only took 8 seconds. So much faster then the bulkinsert one above. Now I tried the other tutorial. USE [Test] GO /****** Object: StoredProcedure [dbo].[spTEST_InsertXMLTEST_TEST] Script Date: 05/19/2010 15:39:03 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE [dbo].[spTEST_InsertXMLTEST_TEST](@UpdatedProdData nText) AS DECLARE @hDoc int exec sp_xml_preparedocument @hDoc OUTPUT,@UpdatedProdData INSERT INTO TBL_TEST_TEST(NAME) SELECT XMLProdTable.NAME FROM OPENXML(@hDoc, 'ArrayOfTBL_TEST_TEST/TBL_TEST_TEST', 2) WITH ( ID Int, NAME varchar(100) ) XMLProdTable EXEC sp_xml_removedocument @hDoc C# code. /// <summary> /// This is using linq to sql to make the table objects. /// It is then serailzed to to an xml document and sent to a stored proedure /// that then does a bulk insert(I think with OpenXML) /// http://www.codeproject.com/KB/linq/BulkOperations_LinqToSQL.aspx /// </summary> private static void LinqInsertXMLBatch() { using (TestDataContext db = new TestDataContext()) { TBL_TEST_TEST[] testRecords = new TBL_TEST_TEST[500000]; for (int count = 0; count < 500000; count++) { TBL_TEST_TEST testRecord = new TBL_TEST_TEST(); testRecord.NAME = "Name : " + count; testRecords[count] = testRecord; } StringBuilder sBuilder = new StringBuilder(); System.IO.StringWriter sWriter = new System.IO.StringWriter(sBuilder); XmlSerializer serializer = new XmlSerializer(typeof(TBL_TEST_TEST[])); serializer.Serialize(sWriter, testRecords); db.insertTestData(sBuilder.ToString()); } } So I like this because I get to use objects even though it is kinda redundant. I don't get how the SP works. Like I don't get the whole thing. I don't know if OPENXML has some batch insert under the hood but I do not even know how to take this example SP and change it to fit my tables since like I said I don't know what is going on. I also don't know what would happen if the object you have more tables in it. Like say I have a ProductName table what has a relationship to a Product table or something like that. In linq to sql you could get the product name object and make changes to the Product table in that same object. So I am not sure how to take that into account. I am not sure if I would have to do separate inserts or what. The time was pretty good for 500,000 records it took 52 seconds The last way of course was just using linq to do it all and it was pretty bad. /// <summary> /// This is using linq to sql to to insert lots of records. /// This way is slow as it uses no mass insert. /// Only tried to insert 50,000 records as I did not want to sit around till it did 500,000 records. /// http://www.codeproject.com/KB/linq/BulkOperations_LinqToSQL.aspx /// </summary> private static void LinqInsertAll() { using (TestDataContext db = new TestDataContext()) { db.CommandTimeout = 600; for (int count = 0; count < 50000; count++) { TBL_TEST_TEST testRecord = new TBL_TEST_TEST(); testRecord.NAME = "Name : " + count; db.TBL_TEST_TESTs.InsertOnSubmit(testRecord); } db.SubmitChanges(); } } I did only 50,000 records and that took over a minute to do. So I really narrowed it done to the linq to sql bulk insert way or bulk copy. I am just not sure how to do it when you have relationship for either way. I am not sure how they both stand up when doing updates instead of inserts as I have not gotten around to try it yet. I don't think I will ever need to insert/update more than 50,000 records at one type but at the same time I know I will have to do validation on records before inserting so that will slow it down and that sort of makes linq to sql nicer as your got objects especially if your first parsing data from a xml file before you insert into the database. Full C# code using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Xml.Serialization; using System.Data; using System.Data.SqlClient; namespace TestIQueryable { class Program { private static string connectionString = ""; static void Main(string[] args) { BatchInsert(); Console.WriteLine("done"); } /// <summary> /// This is using linq to sql to to insert lots of records. /// This way is slow as it uses no mass insert. /// Only tried to insert 50,000 records as I did not want to sit around till it did 500,000 records. /// http://www.codeproject.com/KB/linq/BulkOperations_LinqToSQL.aspx /// </summary> private static void LinqInsertAll() { using (TestDataContext db = new TestDataContext()) { db.CommandTimeout = 600; for (int count = 0; count < 50000; count++) { TBL_TEST_TEST testRecord = new TBL_TEST_TEST(); testRecord.NAME = "Name : " + count; db.TBL_TEST_TESTs.InsertOnSubmit(testRecord); } db.SubmitChanges(); } } /// <summary> /// This is using linq to sql to make the table objects. /// It is then serailzed to to an xml document and sent to a stored proedure /// that then does a bulk insert(I think with OpenXML) /// http://www.codeproject.com/KB/linq/BulkOperations_LinqToSQL.aspx /// </summary> private static void LinqInsertXMLBatch() { using (TestDataContext db = new TestDataContext()) { TBL_TEST_TEST[] testRecords = new TBL_TEST_TEST[500000]; for (int count = 0; count < 500000; count++) { TBL_TEST_TEST testRecord = new TBL_TEST_TEST(); testRecord.NAME = "Name : " + count; testRecords[count] = testRecord; } StringBuilder sBuilder = new StringBuilder(); System.IO.StringWriter sWriter = new System.IO.StringWriter(sBuilder); XmlSerializer serializer = new XmlSerializer(typeof(TBL_TEST_TEST[])); serializer.Serialize(sWriter, testRecords); db.insertTestData(sBuilder.ToString()); } } /// <summary> /// An ado.net 2.0 way to mass insert records. This seems to be the fastest. /// http://www.codeproject.com/KB/cs/MultipleInsertsIn1dbTrip.aspx#_Toc196622241 /// </summary> private static void BatchBulkCopy() { // Get the DataTable DataTable dtInsertRows = GetDataTable(); using (SqlBulkCopy sbc = new SqlBulkCopy(connectionString, SqlBulkCopyOptions.KeepIdentity)) { sbc.DestinationTableName = "TBL_TEST_TEST"; // Number of records to be processed in one go sbc.BatchSize = 500000; // Map the Source Column from DataTabel to the Destination Columns in SQL Server 2005 Person Table // sbc.ColumnMappings.Add("ID", "ID"); sbc.ColumnMappings.Add("NAME", "NAME"); // Number of records after which client has to be notified about its status sbc.NotifyAfter = dtInsertRows.Rows.Count; // Event that gets fired when NotifyAfter number of records are processed. sbc.SqlRowsCopied += new SqlRowsCopiedEventHandler(sbc_SqlRowsCopied); // Finally write to server sbc.WriteToServer(dtInsertRows); sbc.Close(); } } /// <summary> /// Another ado.net 2.0 way that uses a stored procedure to do a bulk insert. /// Seems slower then "BatchBulkCopy" way and it crashes when you try to insert 500,000 records in one go. /// http://www.codeproject.com/KB/cs/MultipleInsertsIn1dbTrip.aspx#_Toc196622241 /// </summary> private static void BatchInsert() { // Get the DataTable with Rows State as RowState.Added DataTable dtInsertRows = GetDataTable(); SqlConnection connection = new SqlConnection(connectionString); SqlCommand command = new SqlCommand("sp_BatchInsert", connection); command.CommandType = CommandType.StoredProcedure; command.UpdatedRowSource = UpdateRowSource.None; // Set the Parameter with appropriate Source Column Name command.Parameters.Add("@Name", SqlDbType.VarChar, 50, dtInsertRows.Columns[0].ColumnName); SqlDataAdapter adpt = new SqlDataAdapter(); adpt.InsertCommand = command; // Specify the number of records to be Inserted/Updated in one go. Default is 1. adpt.UpdateBatchSize = 500000; connection.Open(); int recordsInserted = adpt.Update(dtInsertRows); connection.Close(); } private static DataTable GetDataTable() { // You First need a DataTable and have all the insert values in it DataTable dtInsertRows = new DataTable(); dtInsertRows.Columns.Add("NAME"); for (int i = 0; i < 500000; i++) { DataRow drInsertRow = dtInsertRows.NewRow(); string name = "Name : " + i; drInsertRow["NAME"] = name; dtInsertRows.Rows.Add(drInsertRow); } return dtInsertRows; } static void sbc_SqlRowsCopied(object sender, SqlRowsCopiedEventArgs e) { Console.WriteLine("Number of records affected : " + e.RowsCopied.ToString()); } } }

  Read the article

< Previous Page | 126 127 128 129 130 131 132 133 134 135 136 137  | Next Page >