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  • PHP: Array of objects is empty when I come to retrieve one from the array

    - by Tom
    Good morning, I am trying to load rows from a database and then create objects from them and add these objects to a private array. Here are my classes: <?php include("databaseconnect.php"); class stationItem { private $code = ''; private $description = ''; public function setCode($code ){ $this->code = $code; } public function getCode(){ return $this->code; } public function setDescription($description){ $this->description = $description; } public function getDescription(){ return $this->description; } } class stationList { private $stationListing; function __construct() { connect(); $stationListing = array(); $result = mysql_query('SELECT * FROM stations'); while ($row = mysql_fetch_assoc($result)) { $station = new stationItem(); $station->setCode($row['code']); $station->setDescription($row['description']); array_push($stationListing, $station); } mysql_free_result($result); } public function getStation($index){ return $stationListing[$index]; } } ?> As you can see I am creating a stationItem object per database row (which for now has a code and description) and I then push these on to the end of my array which is held as a private variable in stationList. This is code which creates this classes and attempts to access the properties on them: $stations = new stationList(); $station = $stations->getStation(0); echo $station->getCode(); I am finding that the sizeof($stationList) at the end of the constructor is 1 but then it is zero when we come to try to get an object from the array using the index. Therefore the error that I get is: Fatal error: Call to a member function getCode() on a non-object Please can someone explain to me why this is happening? I guess I am misunderstanding how object references work in PHP5.

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  • Database migration pattern for Java?

    - by Eno
    Im working on some database migration code in Java. Im also using a factory pattern so I can use different kinds of databases. And each kind of database im using implements a common interface. What I would like to do is have a migration check that is internal to the class and runs some database schema update code automatically. The actual update is pretty straight forward (I check schema version in a table and compare against a constant in my app to decide whether to migrate or not and between which versions of schema). To make this automatic I was thinking the test should live inside (or be called from) the constructor. OK, fair enough, that's simple enough. My problem is that I dont want the test to run every single time I instantiate a database object (it runs a query so having it run on every construction is not efficient). So maybe this should be a class static method? I guess my question is, what is a good design pattern for this type of problem? There ought to be a clean way to ensure the migration test runs only once OR is super-efficient.

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  • IoC & Interfaces Best Practices

    - by n8wrl
    I'm experimenting with IoC on my way to TDD by fiddling with an existing project. In a nutshell, my question is this: what are the best practices around IoC when public and non-public methods are of interest? There are two classes: public abstract class ThisThingBase { public virtual void Method1() {} public virtual void Method2() {} public ThatThing GetThat() { return new ThatThing(this); } internal virtual void Method3() {} internal virtual void Method4() {} } public class Thathing { public ThatThing(ThisThingBase thing) { m_thing = thing; } ... } ThatThing does some stuff using its ThisThingBase reference to call methods that are often overloaded by descendents of ThisThingBase. Method1 and Method2 are public. Method3 and Method4 are internal and only used by ThatThings. I would like to test ThatThing without ThisThing and vice-versa. Studying up on IoC my first thought was that I should define an IThing interface, implement it by ThisThingBase and pass it to the ThatThing constructor. IThing would be the public interface clients could call but it doesn't include Method3 or Method4 that ThatThing also needs. Should I define a 2nd interface - IThingInternal maybe - for those two methods and pass BOTH interfaces to ThatThing?

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  • .NET XML serialization

    - by ShdNx
    I would like to serialize and deserialize mixed data into XML. After some searches I found out that there were two ways of doing it: System.Runtime.Serialization.Formatters.Soap.SoapFormatter and System.Xml.Serialization.XmlSerializer. However, neither turned out to match my requirements, since: SoapFormatter doesn't support serialization of generic types XmlSerializer refuses to serialize types that implement IDictionary, not to mention that it's far less easy-to-use than "normal" serialization (e.g. see this SO question) I'm wondering if there exists an implementation that doesn't have these limitations? I have found attempts (for example CustomXmlSerializer and YAXLib as suggested in a related SO question), but they don't seem to work either. I was thinking about writing such serializer myself (though it certainly doesn't seem to be a very easy task), but then I find myself limited by the CLR, as I cannot create object instances of types that won't have a paramaterless constructor, even if I'm using reflection. I recall having read somewhere that implementations in System.Runtime.Serialization somehow bypass the normal object creation mechanism when deserializing objects, though I'm not sure. Any hints of how could this be done? Could somebody please point me to the right direction with this?

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  • How to use delegate to perform callback between caller and web service helper class?

    - by codemonkie
    I have 2 classes A and B, where they belongs to the same namespace but resides in seperate files namely a.cs and b.cs, where class B essentially is a helper wrapping a web service call as follow: public class A { public A() // constructor { protected static B b = new B(); } private void processResult1(string result) { // come here when result is successful } private void processResult2(string result) { // come here when result is failed } static void main() { b.DoJobHelper(...); } } public class B { private com.nowhere.somewebservice ws; public B() { this.ws = new com.nowhere.somewebservice(); ws.JobCompleted += new JobCompletedEventHandler(OnCompleted); } void OnCompleted(object sender, JobCompletedEventArgs e) { string s = e.Result; Guid taskID = (Guid)e.UserState; switch (s) { case "Success": // Call processResult1(); break; case "Failed": // Call processResult2(); break; default: break; } } public void DoJobHelper() { Object userState = Guid.NewGuid(); ws.DoJob(..., userState); } } (1) I have seen texts on the net on using delegates for callbacks but failed to apply that to my case. All I want to do is to call the appropriate processResult() method upon OnCompleted() event, but dunno how to and where to declare the delegate: public delegate void CallBack(string s); (2) There is a sender object passed in to OnCompleted() but never used, did I miss anything there? Or how can I make good use of sender? Any helps appreciated.

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  • HttpWebRequest Timeouts After Ten Consecutive Requests

    - by Bob Mc
    I'm writing a web crawler for a specific site. The application is a VB.Net Windows Forms application that is not using multiple threads - each web request is consecutive. However, after ten successful page retrievals every successive request times out. I have reviewed the similar questions already posted here on SO, and have implemented the recommended techniques into my GetPage routine, shown below: Public Function GetPage(ByVal url As String) As String Dim result As String = String.Empty Dim uri As New Uri(url) Dim sp As ServicePoint = ServicePointManager.FindServicePoint(uri) sp.ConnectionLimit = 100 Dim request As HttpWebRequest = WebRequest.Create(uri) request.KeepAlive = False request.Timeout = 15000 Try Using response As HttpWebResponse = DirectCast(request.GetResponse, HttpWebResponse) Using dataStream As Stream = response.GetResponseStream() Using reader As New StreamReader(dataStream) If response.StatusCode <> HttpStatusCode.OK Then Throw New Exception("Got response status code: " + response.StatusCode) End If result = reader.ReadToEnd() End Using End Using response.Close() End Using Catch ex As Exception Dim msg As String = "Error reading page """ & url & """. " & ex.Message Logger.LogMessage(msg, LogOutputLevel.Diagnostics) End Try Return result End Function Have I missed something? Am I not closing or disposing of an object that should be? It seems strange that it always happens after ten consecutive requests. Notes: In the constructor for the class in which this method resides I have the following: ServicePointManager.DefaultConnectionLimit = 100 If I set KeepAlive to true, the timeouts begin after five requests. All the requests are for pages in the same domain. EDIT I added a delay between each web request of between two and seven seconds so that I do not appear to be "hammering" the site or attempting a DOS attack. However, the problem still occurs.

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  • Trace PRISM / CAL events (best practice?)

    - by Christian
    Ok, this question is for people with either a deep knowledge of PRISM or some magic skills I just lack (yet). The Background is simple: Prism allows the declaration of events to which the user can subscribe or publish. In code this looks like this: _eventAggregator.GetEvent<LayoutChangedEvent>().Subscribe(UpdateUi, true); _eventAggregator.GetEvent<LayoutChangedEvent>().Publish("Some argument"); Now this is nice, especially because these events are strongly typed, and the declaration is a piece of cake: public class LayoutChangedEvent : CompositePresentationEvent<string> { } But now comes the hard part: I want to trace events in some way. I had the idea to subscribe using a lambda expression calling a simple log message. Worked perfectly in WPF, but in Silverlight there is some method access error (took me some time to figure out the reason).. If you want to see for yourself, try this in Silverlight: eA.GetEvent<VideoStartedEvent>().Subscribe(obj => TraceEvent(obj, "vSe", log)); If this would be possible, I would be happy, because I could easily trace all events using a single line to subscribe. But it does not... The alternative approach is writing a different functions for each event, and assign this function to the events. Why different functions? Well, I need to know WHICH event was published. If I use the same function for two different events I only get the payload as argument. I have now way to figure out which event caused the tracing message. I tried: using Reflection to get the causing event (not working) using a constructor in the event to enable each event to trace itself (not allowed) Any other ideas? Chris PS: Writing this text took me most likely longer than writing 20 functions for my 20 events, but I refuse to give up :-) I just had the idea to use postsharp, that would most likely work (although I am not sure, perhaps I end up having only information about the base class).. Tricky and so unimportant topic...

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  • "Public" nested classes or not

    - by Frederick
    Suppose I have a class 'Application'. In order to be initialised it takes certain settings in the constructor. Let's also assume that the number of settings is so many that it's compelling to place them in a class of their own. Compare the following two implementations of this scenario. Implementation 1: class Application { Application(ApplicationSettings settings) { //Do initialisation here } } class ApplicationSettings { //Settings related methods and properties here } Implementation 2: class Application { Application(Application.Settings settings) { //Do initialisation here } class Settings { //Settings related methods and properties here } } To me, the second approach is very much preferable. It is more readable because it strongly emphasises the relation between the two classes. When I write code to instantiate Application class anywhere, the second approach is going to look prettier. Now just imagine the Settings class itself in turn had some similarly "related" class and that class in turn did so too. Go only three such levels and the class naming gets out out of hand in the 'non-nested' case. If you nest, however, things still stay elegant. Despite the above, I've read people saying on StackOverflow that nested classes are justified only if they're not visible to the outside world; that is if they are used only for the internal implementation of the containing class. The commonly cited objection is bloating the size of containing class's source file, but partial classes is the perfect solution for that problem. My question is, why are we wary of the "publicly exposed" use of nested classes? Are there any other arguments against such use?

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  • Loading and binding a serialized view model to a WPF window?

    - by generalt
    Hello all. I'm writing a one-window UI for a simple ETL tool. The UI consists of the window, the code behind for the window, a view model for the window, and the business logic. I wanted to provide functionality to the users to save the state of the UI because the content of about 10-12 text boxes will be reused between sessions, but are specific to the user. I figured I could serialize the view model, which contains all the data from the textboxes, and this works fine, but I'm having trouble loading the information in the serialized XML file back into the text boxes. Constructor of window: public ETLWindow() { InitializeComponent(); _viewModel = new ViewModel(); this.DataContext = _viewModel; _viewModel.State = Constants.STATE_IDLE; Loaded += new RoutedEventHandler(MainWindow_Loaded); } XAML: <TextBox x:Name="targetDirectory" IsReadOnly="true" Text="{Binding TargetDatabaseDirectory, UpdateSourceTrigger=PropertyChanged}"/> ViewModel corresponding property: private string _targetDatabaseDirectory; [XmlElement()] public string TargetDatabaseDirectory { get { return _targetDatabaseDirectory; } set { _targetDatabaseDirectory = value; OnPropertyChanged(DataUtilities.General.Utilities.GetPropertyName(() => new ViewModel().TargetDatabaseDirectory)); } Load event in code behind: private void loadState_Click(object sender, RoutedEventArgs e) { string statePath = this.getFilePath(); _viewModel = ViewModel.LoadModel(statePath); } As you can guess, the LoadModel method deserializes the serialized file on the user's drive. I couldn't find much on the web regarding this issue. I know this probably has something to do with my bindings. Is there some way to refresh on the bindings on the XAML after I deserialize the view model? Or perhaps refresh all properties on the view model? Or am I completely insane thinking any of this could be done? Thanks.

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  • pooling with Windsor

    - by AlonEl
    I've tried out the pooling lifestyle with Windsor. Lets say I want multiple CustomerTasks to work with a pool of ILogger's. when i try resolving more times than maxPoolSize, new loggers keeps getting created. what am i missing and what exactly is the meaning of min and max pool size? the xml configuration i use is (demo code): <component id="customertasks" type="WindsorTest.CustomerTasks, WindsorTestCheck" lifestyle="transient" /> <component id="logger.console" service="WindsorTest.ILogger, WindsorTestCheck" type="WindsorTest.ConsoleLogger, WindsorTestCheck" lifestyle="pooled" initialPoolSize="2" maxPoolSize="5" /> Code is: public interface ILogger { void Log(string message); } public class ConsoleLogger : ILogger { private static int count = 0; public ConsoleLogger() { Console.WriteLine("Hello from constructor number:" + count); count++; } public void Log(string message) { Console.WriteLine(message); } } public class CustomerTasks { private readonly ILogger logger; public CustomerTasks(ILogger logger) { this.logger = logger; } public void SaveCustomer() { logger.Log("Saved customer"); } }

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  • Winforms: How to display a "loading" form?

    - by Martijn
    I have a grid and when a row is double clicked a form is loaded. However a lot of data must be loaded, so I'd like to display a simple form with the text 'loading, please wait..'. And when all loading is finished, the form must disappear. This is what I have right now, but it doesn't work: Code that invokes the form with lots of data: FormWithLotData form = new FormWithLotData(); form.ShowDialog(this); Constructor of FormWithLotData: // Show load form FormIsLoading frm = new FormIsLoading(); _CloseLoadForm closeForm = new _CloseLoadForm(frm.Close); System.Threading.Thread thread = new System.Threading.Thread(frm.Show); thread.Start(); InitializeComponent(); this.Visible = false; LoadAllData(); this.Visible = true; // Close load form Invoke(closeForm); Hope you can help me out. EDIT: I'd like to show an animated gif on the loading form.

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  • Why I cannot add a JPanel to JFrame?

    - by Roman
    Here is the code: import javax.swing.SwingUtilities; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JLabel; import java.awt.event.*; import java.awt.*; public class GameWindow { private String[] players; private JFrame frame; // Constructor. public GameWindow(String[] players) { this.players = players; } // Start the window in the EDT. public void start() { SwingUtilities.invokeLater(new Runnable() { public void run() { showWindow(); controller.start(); } }); } // Defines the general properties of and starts the window. public void showWindow() { frame = new JFrame("Game"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(600,400); frame.setVisible(true); } // The thread controlling changes of panels in the main window. private Thread controller = new Thread() { public void run() { frame.add(generatePartnerSelectionPanel()); frame.invalidate(); frame.validate(); } }; // Generate the panel for the selection of a partner. private JPanel generatePartnerSelectionPanel() { JPanel panel = new JPanel(); panel.add(new JLabel("Pleas select a partner:")); return panel; } } I should see "Pleas select the partner" and I don't. Why? I suppose that it's because I do not see frame from the run method of the Thread.

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  • Java Swing NullPointerException when drawing

    - by juFo
    I'm using a custom JLayeredPane. I have several Shapes which needed to be drawn on different layers in the JLayeredPane. To test this I create a JPanel and ask its graphics. Then I draw a test rectangle on that JPanel (preparing the graphics) and in my paintComponent method from the JLayeredPane I finally draw everything. But this fails (NullPointerException). public class MyCustomPanel extends JLayeredPane { // test JPanel testpane; Graphics g2; // test // constructor public MyCustomPanel() { testpane = new JPanel(); this.add(testpane, new Integer(14)); g2 = testpane.getGraphics(); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); g2.drawRect(10, 10, 300, 300); } } // run: //Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException // at view.MyCustomPanel.paintComponent(MyCustomPanel.java:65) Why can't I draw on such a JPanel from within my JLayeredPane? I can draw directly on my JLayeredPane from within my paintComponent method but that's on the default Panel from the JLayeredPane. I need to create and draw on several layers which are added in my JLayeredPane. What am I doing wrong? :s

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  • OpenCMS - Search field of custom bean

    - by Luigi 1982
    Hi at all... I make some beans with information from VFS of OpenCMS. I want to make searchable the data of my beans. I follow this step but without success: 1) Extends my bean class with CmsSearch and ovverride init method. After I make some stuff for the constructor of my bean: /* Some stuff for CMSSearch */ /** Constant for the fields we will search */ static final String[] DOC_QRY_FIELDS = new String[] {"oggettoDocumento","dataPubblicazione", "societa"}; /** The names of our search index files */ static final String OFFLINE_INDEX = "all_bacheca"; static final String ONLINE_INDEX = "all_bacheca"; public DocumentBean(){ super(); m_parameters.setSort(CmsSearchParameters.SORT_DEFAULT); m_parameters.setFields(Arrays.asList(DocumentBean.DOC_QRY_FIELDS)); m_parameters.setIndex(ONLINE_INDEX); m_parameters.setMatchesPerPage(20); } public void init(CmsObject cms) { super.init(cms); // set search index to offline or online based on current //user project if (cms.getRequestContext().currentProject().isOnlineProject()) { m_parameters.setIndex(ONLINE_INDEX); } else { m_parameters.setIndex(OFFLINE_INDEX); } } // getters and setters.. 2) Configure a new DocumentField with the new field 3) Adding code to my jsp: <input type="hidden" name="field" value="oggettoDocumento"/> But nothing... How can I perform the custom bean search? I can't find any document.. If anyone know some info, basic.. is good for me.. Thanks!

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  • Using prepared statements with JDBCTemplate

    - by Bernhard V
    Hi. I'm using the Jdbc template and want to read from the database using prepared statements. I iterate over many lines in a csv file and on every line I execute some sql select queries with it's values. Now I want to speed up my reading from the database but I just can't get the Jdbc template to work with prepared statements. Actually I even don't know how to do it. There is the PreparedStatementCreator and the PreparedStatementCreator. As in this example both of them are created with anonymous inner classes. But inside the PreparedStatementCreator class I don't have access to the values I want to set in the prepared statement. Since I'm iterating through a csv file I can't hard code them as a String because I don't know them. I also can't pass them to the PreparedStatementCreator because there are no arguments for the constructor. I was used to the creation of prepared statements being fairly simple. Something like PreparedStatement updateSales = con.prepareStatement( "UPDATE COFFEES SET SALES = ? WHERE COF_NAME LIKE ? "); updateSales.setInt(1, 75); updateSales.setString(2, "Colombian"); updateSales.executeUpdate(): as in the Java tutorial. Your help would be very appreciated.

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  • how can i use gwt-test-utils to work with gin?

    - by krrish
    i tried using the steps in http://code.google.com/p/gwt-test-utils/wiki/HowToUseWithGIN and i'm using testNG but it is giving fallowing error java.lang.ExceptionInInitializerError at com.riskfocus.examples.JsonReaderWriterTest.setupGIN(JsonReaderWriterTest.java:59) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:80) at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:551) at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:213) at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:138) at org.testng.internal.TestMethodWorker.invokeBeforeClassMethods(TestMethodWorker.java:175) at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:107) at org.testng.TestRunner.privateRun(TestRunner.java:768) at org.testng.TestRunner.run(TestRunner.java:617) at org.testng.SuiteRunner.runTest(SuiteRunner.java:334) at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329) at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291) at org.testng.SuiteRunner.run(SuiteRunner.java:240) at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53) at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:87) at org.testng.TestNG.runSuitesSequentially(TestNG.java:1185) at org.testng.TestNG.runSuitesLocally(TestNG.java:1110) at org.testng.TestNG.run(TestNG.java:1022) at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:109) at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:202) at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:173) Caused by: java.lang.UnsupportedOperationException: ERROR: GWT.create() is only usable in client code! It cannot be called, for example, from server code. If you are running a unit test, check that your test case extends GWTTestCase and that GWT.create() is not called from within an initializer or constructor. at com.google.gwt.core.client.GWT.create(GWT.java:91) at com.riskfocus.examples.client.model.StockPriceJsonReaderWriter.<clinit>(StockPriceJsonReaderWriter.java:12) ... 25 more

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  • Wrapping FUSE from Go

    - by Matt Joiner
    I'm playing around with wrapping FUSE with Go. However I've come stuck with how to deal with struct fuse_operations. I can't seem to expose the operations struct by declaring type Operations C.struct_fuse_operations as the members are lower case, and my pure-Go sources would have to use C-hackery to set the members anyway. My first error in this case is "can't set getattr" in what looks to be the Go equivalent of a default copy constructor. My next attempt is to expose an interface that expects GetAttr, ReadLink etc, and then generate C.struct_fuse_operations and bind the function pointers to closures that call the given interface. This is what I've got (explanation continues after code): package fuse // #include <fuse.h> // #include <stdlib.h> import "C" import ( //"fmt" "os" "unsafe" ) type Operations interface { GetAttr(string, *os.FileInfo) int } func Main(args []string, ops Operations) int { argv := make([]*C.char, len(args) + 1) for i, s := range args { p := C.CString(s) defer C.free(unsafe.Pointer(p)) argv[i] = p } cop := new(C.struct_fuse_operations) cop.getattr = func(*C.char, *C.struct_stat) int {} argc := C.int(len(args)) return int(C.fuse_main_real(argc, &argv[0], cop, C.size_t(unsafe.Sizeof(cop)), nil)) } package main import ( "fmt" "fuse" "os" ) type CpfsOps struct { a int } func (me *CpfsOps) GetAttr(string, *os.FileInfo) int { return -1; } func main() { fmt.Println(os.Args) ops := &CpfsOps{} fmt.Println("fuse main returned", fuse.Main(os.Args, ops)) } This gives the following error: fuse.go:21[fuse.cgo1.go:23]: cannot use func literal (type func(*_Ctype_char, *_Ctype_struct_stat) int) as type *[0]uint8 in assignment I'm not sure what to pass to these members of C.struct_fuse_operations, and I've seen mention in a few places it's not possible to call from C back into Go code. If it is possible, what should I do? How can I provide the "default" values for interface functions that acts as though the corresponding C.struct_fuse_operations member is set to NULL?

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  • Find all substrings of a string - StringIndexOutOfBoundsException

    - by nazar_art
    I created class Word. Word has a constructor that takes a string argument and one method getSubstrings which returns a String containing all substring of word, sorted by length. For example, if the user provides the input "rum", the method returns a string that will print like this: r u m ru um rum I want to concatenate the substrings in a String, separating them with a newline ("\n"). Then return the string. Code: public class Word { String word; public Word(String word) { this.word = word; } /** * Gets all the substrings of this Word. * @return all substrings of this Word separated by newline */ public String getSubstrings() { String str = ""; int i, j; for (i = 0; i < word.length(); i++) { for (j = 0; j < word.length(); j++) { str = word.substring(i, i + j); str += "\n"; } } return str; } But it throws exception: java.lang.StringIndexOutOfBoundsException: String index out of range: -1 at java.lang.String.substring(String.java:1911) I stuck at this point. Maybe, you have other suggestions according this method signature public String getSubstrings(). How to solve this issue?

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  • Strategies for serializing an object for auditing/logging purpose in .NET?

    - by Jiho Han
    Let's say I have an application that processes messages. Messages are just objects in this case that implements IMessage interface which is just a marker. In this app, if a message fails to process, then I want to log it, first of all for auditing and troubleshooting purposes. Secondly I might want to use it for re-processing. Ideally, I want the message to be serialized into a format that is human-readable. The first candidate is XML although there are others like JSON. If I were to serialize the messages as XML, I want to know whether the message object is XML-serializable. One way is to reflect on the type and to see if it has a parameter-less constructor and the other is to require IXmlSerializable interface. I'm not too happy with either of these approaches. There is a third option which is to try to serialize it and catch exceptions. This doesn't really help - I want to, in some way, stipulate that IMessage (or a derived type) should be xml-serializable. The reflection route has obvious disadvantages such as security, performance, etc. IXmlSerializable route locks down my messages to one format, when in the future, I might want to change the serialization format to be JSON. The other thing is even the simplest objects now must implement ReadXml and WriteXml methods. Is there a route that involves the least amount of work that lets me serialize an arbitrary object (as long as it implements the marker interface) into XML but not lock future messages into XML?

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  • FileNotFoundException, although the XML file should be deployed

    - by Bernhard V
    Hi, I've got problems starting my WAR application on a local JBoss. After two other EARs are deployed and the TomcatDeployer begins deploying the WAR, I'm getting the following error message: 2010-04-28 10:01:56,605 ERROR [org.jboss.ejb.plugins.LogInterceptor] [] [main] EJBException in method: public abstract at.sozvers.stp.zpv.ejb.lea.rwsuc.EJBLeaRegelwerkSuchenRemote at.sozvers.stp.zpv.ejb.lea.rwsuc.EJBLeaRegelwerkSuchenHome.create() throws javax.ejb.CreateException,java.rmi.RemoteException, causedBy: javax.ejb.EJBException: org.springframework.beans.factory.access.BootstrapException: Unable to initialize group definition. Group resource name [classpath*:applicationContext.xml], factory key [contextService]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'contextService' defined in URL [jar:file:/C:/ta30/nutzb/jboss-4.2.3.GA.ZPV/server/default/deploy/deploy.last/zpv-app-web-frontend-1.0-SNAPSHOT.war/WEB-INF/lib/zpv-comp-ejb-modules-1.0-SNAPSHOT-client.jar!/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.context.support.ClassPathXmlApplicationContext]: Constructor threw exception; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [at/sozvers/stp/zpv/dao/ContextBasic.xml]; nested exception is java.io.FileNotFoundException: class path resource [at/sozvers/stp/zpv/dao/ContextBasic.xml] cannot be opened because it does not exist The sad thing is that the resource at/sozvers/stp/zpv/dao/ContextBasic.xml actually is placed in a JAR in one of my EAR files which should be deployed before the WAR. And at least I get a message that the deployment of the EAR has been successful. I also looked into the JAR with my file archiver and the ContextBasic.xml is indeed there at the right place. Is there a way for me to get sure that the JAR, not the EAR as a whole, is really deployed to the JBoss? I'm already starting to lose my head about this issue. Thank you. Bernhard

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  • Android SQLite database locale, locking, and version

    - by gdoten
    In some books and online I see these method calls being made after a database is created: db.setLocale(Locale.getDefault()); db.setLockingEnabled(true); db.setVersion(DB_VERSION); Why is this done? As far as I can tell, after creating a new database, the system adds a table named android_metadata with one field named locale and that table has one row with the locale field set to "en_US". Now I assume the column has that value because I am using a U.S. phone, and if I were using a phone from a different region then the locale field would be set appropriately. Can anyone confirm this? I'm guessing that the setLocale method would only be useful in the case that you install a pre-built database onto a phone and then want to change the locale to match the phone's locale. Sound right? The documentation for setLockingEnabled says it defaults to true so there's no need to make that call, right? Lastly, what's with the call to setVersion? I can't find a table that contains this information so I've been assuming that the database file itself stores the version number somewhere. So when I create a database, which requires you to have already specified the version number in the call to the SQLiteOpenHelper constructor, there's no point in calling setVersion. Again, perhaps this method exists for the case of installing a pre-built database to a device and you then wish to change the database's version (though I can't think of when doing this would make sense). Thanks for any insight!

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  • WPF Spellcheck Engine takes up too much memory.

    - by Matt H.
    Each datatemplate in my WPF ItemsControl contains FIVE custom bindable richtextbox controls. It is a data-driven app that for authoring multiple-choice questions -- The question and four answer choices must all support: 1) Spell check 2) Rich formatting (otherwise I'd use regular textboxes) The spell check object in .NET 4 has a Friend constructor that takes a single argument of owner As TextBoxBase This means every richtextbox in the ItemsControl has 5 Spellcheck objects! This is the problem -- every spell check engine is consuming about 500k memory. So after you favor in the spellcheck, bindings, additional controls in the DataTemplate, etc.. a single multi choice question consumes more than 3MB memory. Users with 100--200 questions will quickly see the App raise it's memory consumption to 500+ MB. Management is definitely not OK with this. Is there a way to minimimze this problem? The best suggestion I've heard is to enable/disable spellcheck if the richtextbox is in the ItemsControl's scrollviewer: I haven't gotten an answer to how to go about it: (http://stackoverflow.com/questions/2869012/possible-to-implement-an-isviewportvisible-dependencyproperty-for-an-item-in-an-i) Any good ideas?

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  • Qt 5.3 OpenGL - vertex buffer object drawing using the core profile

    - by user3700881
    Im using Qt 5.3 to create a QWindow to do some basic rendering stuff. The QWindow is declared like this: class OpenGLWindow : public QWindow, protected QOpenGLFunctions_3_3_Core { Q_OBJECT ... } It is initialized in the constructor: OpenGLWindow::OpenGLWindow(QWindow *parent) : QWindow(parent) { QSurfaceFormat format; format.setVersion(3,3); format.setProfile(QSurfaceFormat::CoreProfile); this->setSurfaceType(OpenGLSurface); this->setFormat(format); this->create(); _context = new QOpenGLContext; _context->setFormat(format); _context->create(); _context->makeCurrent(this); this->initializeOpenGLFunctions(); ... } And that's the rendering code: void OpenGLWindow::render() { if(!isExposed()) return; _context->makeCurrent(this); glClear(GL_COLOR_BUFFER_BIT); glUseProgram(_shaderProgram); glBindBuffer(GL_ARRAY_BUFFER, _positionBufferObject); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0); glDrawArrays(GL_TRIANGLES, 0, 3); glDisableVertexAttribArray(0); glUseProgram(0); _context->swapBuffers(this); } I am trying to draw a simple triangle using a vertex and fragment shader. The problem is that the triangle is not showing up when the core profile is set. Only when I set the OpenGL version to 2.0 or when I use the compatibility profile, it shows up. From my point of view that doesn't make any sense because I am not using fixed functionality at all. What am I missing?

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  • Methods for Lazy Initialization with properties

    - by Stuart Pegg
    I'm currently altering a widely used class to move as much of the expensive initialization from the class constructor into Lazy Initialized properties. Below is an example (in c#): Before: public class ClassA { public readonly ClassB B; public void ClassA() { B = new ClassB(); } } After: public class ClassA { private ClassB _b; public ClassB B { get { if (_b == null) { _b = new ClassB(); } return _b; } } } There are a fair few more of these properties in the class I'm altering, and some are not used in certain contexts (hence the Laziness), but if they are used they're likely to be called repeatedly. Unfortunately, the properties are often also used inside the class. This means there is a potential for the private variable (_b) to be used directly by a method without it being initialized. Is there a way to make only the public property (B) available inside the class, or even an alternative method with the same initialized-when-needed? This is reposted from Programmers (not subjective enough apparently): http://programmers.stackexchange.com/questions/34270/best-methods-for-lazy-initialization-with-properties

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  • Android: Change the source of ImageView present in ListView

    - by Vivek
    Hi All, I have a ListView specified by list_item.xml Now I need to change the Image in my list inside onListItemClick. How to achieve this? //list_item.xml <?xml version="1.0" encoding="UTF-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/play" android:id="@+id/img" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_vertical" android:id="@+id/txt" /> </LinearLayout> I have a Custom Adapter to populate my list. Code below is the adapter. public class MyCustomAdapter extends ArrayAdapter<String> { public MyCustomAdapter(Context context, int textViewResourceId, String[] objects) { super(context, textViewResourceId, objects); // TODO Auto-generated constructor stub } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub LayoutInflater inflater=getLayoutInflater(); View row=inflater.inflate(R.layout.list_item, parent, false); TextView label=(TextView)row.findViewById(R.id.txt); label.setText(Sounds[position]); ImageView icon=(ImageView)row.findViewById(R.id.img); icon.setMaxHeight(32); icon.setMaxWidth(32); icon.setPadding(2, 1, 5, 1); icon.setImageResource(R.drawable.play); return row; } } And in onCreate I do the following @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); try { setListAdapter(new MyCustomAdapter(this, R.layout.list_item, Sounds)); //Sounds --> String array } catch(Exception e) { e.printStackTrace(); } } Now when any row is selected, I need to change the image associated with the selected view. Your help is appreciated. Thanks.

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