Search Results

Search found 46894 results on 1876 pages for 'java native interface'.

Page 745/1876 | < Previous Page | 741 742 743 744 745 746 747 748 749 750 751 752  | Next Page >

• Approach for fixing NoClassDefFoundError?

  - by DJC

  I'm seeing this question is getting asked a lot in many different contexts. Perhaps we can set some strategies for locating and fixing it? I'm noobish myself so all I can contribute are horror stories and questions, sorry... It seems this is thrown when a class is visible at compile time but not at run time... how can this happen? In my case I am developing an app that uses the Google APIs, in Eclipse, for the Android platform. I've configured the Project Properties / Java Build Path / Libraries to include the gdata .jars and all is well. When I execute in the emulator I get a force close and the logcat shows a NoClassDefFoundError on a simple new ContactsService("myApp"); I've also tried a new CalendarService("myApp") with the same results. Is it possible or desirable to statically bind at compile time to avoid the problem? How could dynamic binding of an add-on library work in the mobile environment anyway? Either it has to be bound into my .apk or else I need to "install" it? ... hmmm. Advice much appreciated.

  Read the article

• Project euler problem 45

  - by Peter

  Hi, I'm not yet a skilled programmer but I thought this was an interesting problem and I thought I'd give it a go. Triangle, pentagonal, and hexagonal numbers are generated by the following formulae: Triangle T_(n)=n(n+1)/2 1, 3, 6, 10, 15, ... Pentagonal P_(n)=n(3n-1)/2 1, 5, 12, 22, 35, ... Hexagonal H_(n)=n(2n-1) 1, 6, 15, 28, 45, ... It can be verified that T_(285) = P_(165) = H_(143) = 40755. Find the next triangle number that is also pentagonal and hexagonal. Is the task description. I know that Hexagonal numbers are a subset of triangle numbers which means that you only have to find a number where Hn=Pn. But I can't seem to get my code to work. I only know java language which is why I'm having trouble finding a solution on the net womewhere. Anyway hope someone can help. Here's my code public class NextNumber { public NextNumber() { next(); } public void next() { int n = 144; int i = 165; int p = i * (3 * i - 1) / 2; int h = n * (2 * n - 1); while(p!=h) { n++; h = n * (2 * n - 1); if (h == p) { System.out.println("the next triangular number is" + h); } else { while (h > p) { i++; p = i * (3 * i - 1) / 2; } if (h == p) { System.out.println("the next triangular number is" + h); break; } else if (p > h) { System.out.println("bummer"); } } } } } I realize it's probably a very slow and ineffecient code but that doesn't concern me much at this point I only care about finding the next number even if it would take my computer years :) . Peter

  Read the article

• Best XML format for log events in terms of tool support for data mining and visualization?

  - by Thorbjørn Ravn Andersen

  We want to be able to create log files from our Java application which is suited for later processing by tools to help investigate bugs and gather performance statistics. Currently we use the traditional "log stuff which may or may not be flattened into text form and appended to a log file", but this works the best for small amounts of information read by a human. After careful consideration the best bet has been to store the log events as XML snippets in text files (which is then treated like any other log file), and then download them to the machine with the appropriate tool for post processing. I'd like to use as widely supported an XML format as possible, and right now I am in the "research-then-make-decision" phase. I'd appreciate any help both in terms of XML format and tools and I'd be happy to write glue code to get what I need. What I've found so far: log4j XML format: Supported by chainsaw and Vigilog. Lilith XML format: Supported by Lilith Uninvestigated tools: Microsoft Log Parser: Apparently supports XML. OS X log viewer: plus there is a lot of tools on http://www.loganalysis.org/sections/parsing/generic-log-parsers/ Any suggestions?

  Read the article

• Is it possible to order by a composite key with JPA and CriteriaBuilder

  - by Kjir

  I would like to create a query using the JPA CriteriaBuilder and I would like to add an ORDER BY clause. This is my entity: @Entity @Table(name = "brands") public class Brand implements Serializable { public enum OwnModeType { OWNER, LICENCED } @EmbeddedId private IdBrand id; private String code; //bunch of other properties } Embedded class is: @Embeddable public class IdBrand implements Serializable { @ManyToOne private Edition edition; private String name; } And the way I am building my query is like this: CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<Brand> q = cb.createQuery(Brand.class).distinct(true); Root<Brand> root = q.from(Brand.class); if (f != null) { f.addCriteria(cb, q, root); f.addOrder(cb, q, root, sortCol, ascending); } return em.createQuery(q).getResultList(); And here are the functions called: public void addCriteria(CriteriaBuilder cb, CriteriaQuery<?> q, Root<Brand> r) { } public void addOrder(CriteriaBuilder cb, CriteriaQuery<?> q, Root<Brand> r, String sortCol, boolean ascending) { if (ascending) { q.orderBy(cb.asc(r.get(sortCol))); } else { q.orderBy(cb.desc(r.get(sortCol))); } } If I try to set sortCol to something like "id.edition.number" I get the following error: javax.ejb.EJBException: java.lang.IllegalArgumentException: Unable to resolve attribute [id.name] against path Any idea how I could accomplish that? I tried searching online, but I couldn't find a hint about this... Also would be great if I could do a similar ORDER BY when I have a @ManyToOne relationship (for instance, "id.edition.number")

  Read the article

• How to sort HashSet() function data in sequence?

  - by vincent low

  I am new to Java, the function I would like to perform is to load a series of data from a file, into my hashSet() function. the problem is, I able to enter all the data in sequence, but I can't retrieve it out in sequence base on the account name in the file. Can anyone help? below is my code: public Set retrieveHistory(){ Set dataGroup = new HashSet(); try{ File file = new File("C:\\Documents and Settings\\vincent\\My Documents\\NetBeansProjects\\vincenttesting\\src\\vincenttesting\\vincenthistory.txt"); BufferedReader br = new BufferedReader(new FileReader(file)); String data = br.readLine(); while(data != null){ System.out.println("This is all the record:"+data); Customer cust = new Customer(); //break the data based on the , String array[] = data.split(","); cust.setCustomerName(array[0]); cust.setpassword(array[1]); cust.setlocation(array[2]); cust.setday(array[3]); cust.setmonth(array[4]); cust.setyear(array[5]); cust.setAmount(Double.parseDouble(array[6])); cust.settransaction(Double.parseDouble(array[7])); dataGroup.add(cust); //then proced to read next customer. data = br.readLine(); } br.close(); }catch(Exception e){ System.out.println("error" +e); } return dataGroup; } public static void main(String[] args) { FileReadDataModel fr = new FileReadDataModel(); Set customerGroup = fr.retrieveHistory(); System.out.println(e); for(Object obj : customerGroup){ Customer cust = (Customer)obj; System.out.println("Cust name :" +cust.getCustomerName()); System.out.println("Cust amount :" +cust.getAmount()); }

  Read the article

• Design for a Debate club assignment application

  - by Amir Rachum

  Hi all, For my university's debate club, I was asked to create an application to assign debate sessions and I'm having some difficulties as to come up with a good design for it. I will do it in Java. Here's what's needed: What you need to know about BP debates: There are four teams of 2 debaters each and a judge. The four groups are assigned a specific position: gov1, gov2, op1, op2. There is no significance to the order within a team. The goal of the application is to get as input the debaters who are present (for example, if there are 20 people, we will hold 2 debates) and assign them to teams and roles with regards to the history of each debater so that: Each debater should debate with (be on the same team) as many people as possible. Each debater should uniformly debate in different positions. The debate should be fair - debaters have different levels of experience and this should be as even as possible - i.e., there shouldn't be a team of two very experienced debaters and a team of junior debaters. There should be an option for the user to restrict the assignment in various ways, such as: Specifying that two people should debate together, in a specific position or not. Specifying that a single debater should be in a specific position, regardless of the partner. etc... If anyone can try to give me some pointers for a design for this application, I'll be so thankful! Also, I've never implemented a GUI before, so I'd appreciate some pointers on that as well, but it's not the major issue right now.

  Read the article

• How does a client find the port number of a server?

  - by Jonathan

  Hello all, I am currently learning about basic networking in java. I have been playing around with the server and client relationship between two of my computers. However, I cannot figure out how distributed programs (say, a videogame), can not only find the 'host' computer, but also the port number on which the server is running in order to create a Socket between the two computers. The only way I really see to create a Socket is with an already known IP Address, and with a known port number. How do you search a LAN network for another computer (host) searching for clients? How do you determine what port the server is located on without 'pinging' all available ports for a response (which, I understand, is bad form... Something about 'server attack'...)? In such a situation as a video game, there can be any number of computers on the same network, and any number of them might be attempting to host, or otherwise running the application. Any other important information, or perhaps reference to a more detailed tutorial than the one I am using, regarding making connections on so very little information on the client side would be appreciated. Many thanks, Jonathan

  Read the article

• How to call different methods from single webservices class

  - by pointer

  I have a following RESTful webservice, I have two methods for http get. One function signs in and other function signs out a user from an application. Following is the code: import javax.ws.rs.core.Context; import javax.ws.rs.core.UriInfo; import javax.ws.rs.PathParam; import javax.ws.rs.Consumes; import javax.ws.rs.PUT; import javax.ws.rs.Path; import javax.ws.rs.GET; import javax.ws.rs.POST; import javax.ws.rs.Produces; import javax.ws.rs.QueryParam; /** * REST Web Service * * @author Pointer */ @Path("generic") public class GenericResource { @Context private UriInfo context; /** * Creates a new instance of GenericResource */ public GenericResource() { } /** * Retrieves representation of an instance of * com.ef.apps.xmpp.ws.GenericResource * * @return an instance of java.lang.String */ @GET @Produces("text/html") public String SignIn(@QueryParam("username") String username, @QueryParam("password") String password, @QueryParam("extension") String extension) { //TODO return proper representation object return "Credentials " + username + " : " + password + " : " + extension; } @GET @Produces("text/html") public String SignOut(@QueryParam("username") String username, @QueryParam("password") String password, @QueryParam("extension") String extension) { //TODO return proper representation object return "Credentials " + username + " : " + password + " : " + extension; } } Now, where would I specify that which function I want to call for http get?

  Read the article

• Should client-server code be written in one "project" or two?

  - by Ricket

  I've been beginning a client-server application. At first I naturally created two projects in Eclipse, two source control repositories, etc. But I'm quickly seeing that there is a bit of shared code between the two that would probably benefit to sharing instead of copying. In addition, I've been learning and trying test-driven development, and it seems to me that it would be easier to test based on real client components rather than having to set up a huge amount of code just to mock something, when the code is probably mostly in the client. My biggest concern in merging the client and server is of security; how do I ensure that the server pieces of the code do not reach an user's computer? So especially if you are writing client-server applications yourself (and especially in Java, though this can turn into a language-agnostic question if you'd like to share your experience with this in other languages), what sort of separation do you keep between your client and server code? Are they just in different packages/namespaces or completely different binaries using shared libraries, or something else entirely? How do you test the code together and yet ship separately?

  Read the article

• Reverse search in Hibernate Search

  - by Javi

  Hello, I'm using Hibernate Search (which uses Lucene) for searching some Data I have indexed in a directory. It works fine but I need to do a reverse search. By reverse search I mean that I have a list of queries stored in my database I need to check which one of these queries match with a Data object each time Data Object is created. I need it to alert the user when a Data Object matches with a Query he has created. So I need to index this single Data Object which has just been created and see which queries of my list has this object as a result. I've seen Lucene MemoryIndex Class to create an index in memory so I can do something like this example for every query in a list (though iterating in a Java list of queries would not be very efficient): //Iterating over my list<Query> MemoryIndex index = new MemoryIndex(); //Add all fields index.addField("myField", "myFieldData", analyzer); ... QueryParser parser = new QueryParser("myField", analyzer); float score = index.search(query); if (score > 0.0f) { System.out.println("it's a match"); } else { System.out.println("no match found"); } The problem here is that this Data Class has several Hibernate Search Annotations @Field,@IndexedEmbedded,... which indicated how fields should be indexed, so when I invoke index() method on the FullTextEntityManager instance it uses this information to index the object in the directory. Is there a similar way to index it in memory using this information? Is there a more efficient way of doing this reverse search? Thanks

  Read the article

• how to Compute the average probe length for success and failure - Linear probe (Hash Tables)

  - by fang_dejavu

  hi everyone, I'm doing an assignment for my Data Structures class. we were asked to to study linear probing with load factors of .1, .2 , .3, ...., and .9. The formula for testing is: The average probe length using linear probing is roughly Success-- ( 1 + 1/(1-L)**2)/2 or Failure-- (1+1(1-L))/2. we are required to find the theoretical using the formula above which I did(just plug the load factor in the formula), then we have to calculate the empirical (which I not quite sure how to do). here is the rest of the requirements **For each load factor, 10,000 randomly generated positive ints between 1 and 50000 (inclusive) will be inserted into a table of the "right" size, where "right" is strictly based upon the load factor you are testing. Repeats are allowed. Be sure that your formula for randomly generated ints is correct. There is a class called Random in java.util. USE it! After a table of the right (based upon L) size is loaded with 10,000 ints, do 100 searches of newly generated random ints from the range of 1 to 50000. Compute the average probe length for each of the two formulas and indicate the denominators used in each calculationSo, for example, each test for a .5 load would have a table of size approximately 20,000 (adjusted to be prime) and similarly each test for a .9 load would have a table of approximate size 10,000/.9 (again adjusted to be prime). The program should run displaying the various load factors tested, the average probe for each search (the two denominators used to compute the averages will add to 100), and the theoretical answers using the formula above. .** how do I calculate the empirical success?

  Read the article

• How to disable scaling in JFreeChart?

  - by Alex Arnon

  Hi All, We're using JFreeChart to build an engine to display graphs. This is a web service that runs on Tomcat + Java 1.5.0, and renders charts to PNGs and JPEGs (using ChartUtilities.writeChartAs{PNG,JPEG}() ). We've run into a problem where JFreeChart seems to scale everything inside the Plot area, but only by a few pixels. The result is that the graph looks inconsistent, e.g.: Minor ticks are sometimes stretched horizontally, so that they seem to be two pixels wide instead of one. We use a small image in the top-right of the plot area as a watermark. This is stretched by one pixel horizontally and vertically somewhere near (but not exactly) its middle. Background grid lines seem to appear on sub-pixel boundaries. I have not found a way to create an accurately dotted grid line. We have tried both 1.0.9 and 1.0.13, with exactly the same results (except for the minor ticks, which were not available in the older version). Also, rendering the image to a Frame instead of JPEG/PNG produced an identical result. Help is greatly appreciated, in advance :)

  Read the article

• Syntax error results in blank page

  - by Philipp

  I am new to wicket and trying to get some things working. One thing that annoys me a lot is that I get a blank (0 chars of text) page whenever there is a syntax error on a page. Striped down example: Test.html header stuff: doctype ... html ... head ... body ... <span wicket:id="msgTest" id="message">MSG</span> footer stuff: /body ... /html Test.java public class Test extends WebPage { public Test() { add(new Label("msgTest", "Hello, World!")); } } This will output the page as expected. Now, lets introduce an error: header stuff: doctype ... html ... head ... body ... <span wicket:id="msgTest2" id="message">MSG</span> footer stuff: /body ... /html I changed the label-id to something different then what the source-file expects. If I run this code I get the already mentioned blank page. However, for every request to a page with such a syntax error I get an error report in the log-file of around 1000+ lines. This error-report is basically just wicket-generated html of a page which describes the error. This makes me wonder why wicket isn't displaying the error-stuff instead of the blank page. I'm not very experienced with wicket but to me it somehow looks like wicket is having trouble rendering its own error-page code. It would be nice to know how one goes about finding syntax-errors with wicket. Reading through a 1000+ line error-report for a small error like a misplaced character seems a bit tedious. Thanks in advance for guiding me into the right direction :) PS: wicket-version: 1.4.9 stage: development

  Read the article

• how to make war file take up less memory

  - by Myy

  I need help on how to decrease the memory usage of my web app. so I can fit more into my webserver. so I'm building a java web app with JSF 2.0 developing in eclipse helios and running on an Apache tomcat Server. And I have a dedicated virtual server with a tomcat aswell where I deploy these war files. the webApp is about 35MB in size ( it has a lot of jars and such) but when I deploy it to my tomcat webserver, I can see it takes about 300MB of RAM, is this normal? my dedicated server only has 2GB of ram from which normally have 1 to use. so I as soon as I deploy 3 apps I get an OOM error, I've gotten permgen OOM and a out of swamp Memory error; to fix this I upped my MaxPermGen to about a gig and resytarted the server to get back some swamp space. so I tried deploying smaller older apps ( about 15MB) and they take up waay less memory. If I have 1 GB of ram I want to be able to fit more apps into my webserver without getting any OOM Errors. now I found this stack overflow Question, Can that be applied to my case? and if so, which are the common folders in the tomcat server? anyone done this before or have a different more effective, not so complicated approach? Any ideas, and or commets are more than appreciated. Thanks! Myy

  Read the article

• How can you connect to a password protected MS Access Database from a Spring JdbcTemplate?

  - by Tim Visher

  I need to connect to a password protected MS Access 2003 DB using the JDBC-ODBC bridge. I can't find out how to specify the password in the connect string, or even if that is the correct method of connecting. It would probably be relevant to mention that this is a Spring App which is accessing the database through a JdbcTemplate configured as a datasource bean in our application context file. Some relevant snippets: from application-context.xml <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="legacyDataSource" /> </bean> <bean id="jobsheetLocation" class="java.lang.String"> <constructor-arg value="${jobsheet.location}"/> </bean> <bean id="legacyDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${jdbc.legacy.driverClassName}" /> <property name="url" value="${jdbc.legacy.url}"/> <property name="password" value="-------------" /> </bean> from our build properties jdbc.legacy.driverClassName=sun.jdbc.odbc.JdbcOdbcDriver jdbc.legacy.url=jdbc:odbc:Driver\={Microsoft Access Driver (*.mdb)};Dbq\=@LegacyDbPath@;DriverID\=22;READONLY\=true Any thoughts?

  Read the article

• What's the vbs code to schedule a task every time Windows starts up?

  - by Wing C. Chen

  I would like to know how to write up the vbs code to schedule a windows task to start a .exe program every time the Windows starts up. I found the following code online: strComputer = "." Set objWMIService = GetObject("winmgmts:" _ & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2") Set objNewJob = objWMIService.Get("Win32_ScheduledJob") errJobCreated = objNewJob.Create _ ("Notepad.exe", "********123000.000000-420", _ True , 1 OR 4 OR 16, , , JobID) Wscript.Echo errJobCreated But it only tells me how to schedule the task every on some specific days and hours. I thought of creating a windows service. However the following is the story why I must look for an alternative to it. I created a windows service with RunAsService for my java program wrapped with Janel. The Service worked fine when I first installed and started it. However, after restarting my windows xp, a dialog window poped out saying that my janel generated .exe file has crashed, with my RunAsService service kept on going. The service worked fine when I terminated the service and restarted it again manually. Nevertheless, the same crash happens over and over again every time I restart my Windows.

  Read the article

• It is related to core java enums.

  - by Rashmi

  what is singleton instances of the enumeration class in java?

  Read the article

• Binding a null variable in a PreparedStatement

  - by Paul Tomblin

  I swear this used to work, but it's not in this case. I'm trying to match col1, col2 and col3, even if one or more of them is null. I know that in some languages I've had to resort to circumlocutions like ((? is null AND col1 is null) OR col1 = ?). Is that required here? PreparedStatement selStmt = getConn().prepareStatement( "SELECT * " + "FROM tbl1 " + "WHERE col1 = ? AND col2 = ? and col3 = ?"); try { int col = 1; setInt(selStmt, col++, col1); setInt(selStmt, col++, col2); setInt(selStmt, col++, col3); ResultSet rs = selStmt.executeQuery(); try { while (rs.next()) { // process row } } finally { rs.close(); } } finally { selStmt.close(); } // Does the equivalient of stmt.setInt(col, i) but preserves nullness. protected static void setInt(PreparedStatement stmt, int col, Integer i) throws SQLException { if (i == null) stmt.setNull(col, java.sql.Types.INTEGER); else stmt.setInt(col, i); }

  Read the article

• XPath Trouble with getting attributes

  - by Travis

  I'm having a bit of trouble with some XML in Java. The following is the result of an API call to EVE Online. How can I get the "name" and "characterID" for each row? Frankly I just have no idea where to start with this one, so please don't ask for extra information. I just gotta know how to get those attributes. <?xml version='1.0' encoding='UTF-8'?> <eveapi version="1"> <currentTime>2007-12-12 11:48:50</currentTime> <result> <rowset name="characters" key="characterID" columns="name,characterID,corporationName,corporationID"> <row name="Mary" characterID="150267069" corporationName="Starbase Anchoring Corp" corporationID="150279367" /> <row name="Marcus" characterID="150302299" corporationName="Marcus Corp" corporationID="150333466" /> <row name="Dieinafire" characterID="150340823" corporationName="Center for Advanced Studies" corporationID="1000169" /> </rowset> </result> <cachedUntil>2007-12-12 12:48:50</cachedUntil> </eveapi>

  Read the article

• JUnit test failing - complaining of missing data that was just inserted

  - by Collin Peters

  I have an extremely odd problem in my JUnit tests that I just can't seem to nail down. I have a multi-module java webapp project with a fairly standard structure (DAO's, service clasess, etc...). Within this project I have a 'core' project which contains some abstracted setup code which inserts a test user along with the necessary items for a user (in this case an 'enterprise', so a user must belong to an enterprise and this is enforced at the database level) Fairly simple so far... but here is where the strangeness begins some tests fail to run and throw a database exception where it complains that a user cannot be inserted because an enterprise does not exist. But it just created the enterprise in the preceding line of code! And there was no errors in the insertion of the enterprise. Stranger yet, if this test class is run by itself everything works fine. It is only when the test is run as part of the project that it fails! And the exact same abstracted code was run by 10+ tests before the one that fails! f I have been banging my head against a wall with this for days and haven't really made any progress. I'm not even sure what information to offer up to help diagnose this. Using JUnit 4.4, Spring 2.5.6, iBatis 2.3.0, Postgresql 8.3 Switching to org.springframework.jdbc.datasource.DriverManagerDataSource from org.apache.commons.dbcp.BasicDataSource changed the problem. Using DriverManagerDataSource the tests work for the first time, but now all of a sudden a lot of data isn't rolled back in the database! It leaves everything behind. All with no errors Tests fail when run via Eclipse & Maven Please ask for any info which may help me solve my problem!

  Read the article

• Ordering by a max or a min from another table

  - by Paul Tomblin

  I have a table that consists of a unique id, and a few other attributes. It holds "schedules". Then I have another table that holds a list of all the times each schedule has or will "fire". This isn't the exact schema, but it's close: create table schedule ( id varchar(40) primary key, attr1 int, attr2 varchar(20) ); create table schedule_times ( id varchar(40) foreign key schedule(id), fire_date date ); I want to query the schedule table, getting the attributes and the next and previous fire_dates, in Java, sometimes ordering on one of the attributes, but sometimes ordering on either previous fire_date or the next fire_date. Ordering by the attributes is easy, I just stick an "order by" into the string while I'm building my prepared statement. I'm not even sure how to go about selecting the last fire_date and the next one in a single query - I know that I can find the next fire_date for a given id by doing a SELECT min(fire_date) FROM schedule_times WHERE id = ? AND fire_date > sysdate; and the similar thing for previous fire_date using max() and fire_date < sysdate. I'm just drawing a blank on how to incorporate that into a single select from the schedule so I can get both next and previous fire_date in one shot, and also how to order by either of those attributes.

  Read the article

• Wrappers of primitive types in arraylist vs arrays

  - by ismail marmoush

  Hi, In "Core java 1" I've read CAUTION: An ArrayList is far less efficient than an int[] array because each value is separately wrapped inside an object. You would only want to use this construct for small collections when programmer convenience is more important than efficiency. But in my software I've already used Arraylist instead of normal arrays due to some requirements, though "The software is supposed to have high performance and after I've read the quoted text I started to panic!" one thing I can change is changing double variables to Double so as to prevent auto boxing and I don't know if that is worth it or not, in next sample algorithm public void multiply(final double val) { final int rows = getSize1(); final int cols = getSize2(); for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { this.get(i).set(j, this.get(i).get(j) * val); } } } My question is does changing double to Double makes a difference ? or that's a micro optimizing that won't affect anything ? keep in mind I might be using large matrices.2nd Should I consider redesigning the whole program again ?

  Read the article

• JTable Insert row and refresh

  - by user269723

  Hi All, I am trying to create simple application where JTable gets updated and refreshed after data is changed.Structure is as follows. 1)Class Main which contains JFrame,JTable details. 2)SampleTableModel class which extends AbstractTableModel.I am overriding most of the methods.`import javax.swing.table.; import javax.swing.event.; import java.util.*; public class SampleTableModel extends AbstractTableModel { public SampleTableModel(){ // this.addTableModelListener( } String[] columnNames = {"A","B","C","D","E"}; int[][] data = {{1,2,3,4,5},{5,6,7,8,9},{12,13,14,15,16}}; Vector dataVector = new Vector(); public Object getValueAt(int rowIndex,int columnIndex) { return data[rowIndex][columnIndex]; } public int getColumnCount(){ return 5; } public int getRowCount(){ return 3; } public String getColumnName(int columnIndex){ return columnNames[columnIndex]; } public void setValueAt(Object value,int row,int column){ data[row][column] =99; } public void notifyTable(AEMessage message){ /* * This method will be called from another class to update JTable. * */ data[0][1]=999; data[0][2]=8838; data[1][1]=8883; fireTableRowsUpdated(0,3); } } ` As you can see, notifyTable will be called from another class(which is actually a thread-which calls this method frequently) Problem is I don't see data being changed in JTable.I see only the initialized data. In the Main class- I am setting like this- RVJDataTable.setModel(new SampleTableModel());

  Read the article

• How to avoid shell execution of a Process?

  - by adeel amin

  When I start a process like process = Runtime.getRuntime().exec("gnome-terminal");, it starts shell execution. I want to stop shell execution and want to redirect I/O from process, can anybody tell how I can do this? My code is: public void start_process() { try { process= Runtime.getRuntime().exec("gnome-terminal"); pw= new PrintWriter(process.getOutputStream(),true); br=new BufferedReader(new InputStreamReader(process.getInputStream())); err=new BufferedReader(new InputStreamReader(process.getErrorStream())); } catch (Exception ioe) { System.out.println("IO Exception-> " + ioe); } } public void execution_command() { if(check==2) { try { boolean flag=thread.isAlive(); if(flag==true) thread.stop(); Thread.sleep(30); thread = new MyReader(br,tbOutput,err,check); thread.start(); }catch(Exception ex){ JOptionPane.showMessageDialog(null, ex.getMessage()+"1"); } } else { try { Thread.sleep(30); thread = new MyReader(br,tbOutput,err,check); thread.start(); check=2; }catch(Exception ex){ JOptionPane.showMessageDialog(null, ex.getMessage()+"1"); } } } private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: command=tfCmd.getText().toString().trim(); pw.println(command); execution_command(); } When I enter some command in textfield and press execute button, nothing is displayed on my output textarea, how I can stop shell execution and redirect input and output?

  Read the article

• Google app engine: Poor Performance with JDO + Datastore

  - by Bosh

  I have a simple data model that includes USERS: store basic information (key, name, phone # etc) RELATIONS: describe, e.g. a friendship between two users (supplying a relationship_type + two user keys) I'm getting very poor performance, for instance, if I try to print the first names of all of a user's friends. Say the user has 500 friends: I can fetch the list of friend user_ids very easily in a single query. But then, to pull out first names, I have to do 500 back-and-forth trips to the Datastore, each of which seems to take on the order of 30 ms. If this were SQL, I'd just do a JOIN and get the answer out fast. I understand there are rudimentary facilities for performing joins across un-owned relations in a relaxed implementation of JDO (as described at http://gae-java-persistence.blogspot.com) but they sound experimental and non-standard (e.g. my code won't work in any other JDO implementation). Is this really my best bet? Otherwise, how do people extract satisfactory performance from JDO/Datastore in this kind of (very common) situation? -Bosh

  Read the article

< Previous Page | 741 742 743 744 745 746 747 748 749 750 751 752  | Next Page >