Search Results

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

Page 980/1876 | < Previous Page | 976 977 978 979 980 981 982 983 984 985 986 987  | Next Page >

  • Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?

    - by Mulmoth
    It is said to be a good habit to close all JDBC resources after usage. But if I have the following code, is it necessary to close the Resultset and the Statement? Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; try { conn = // Retrieve connection stmt = conn.prepareStatement(// Some SQL); rs = stmt.executeQuery(); } catch { // Error Handling } finally { try { if (rs != null) rs.close(); } catch (Exception e) {}; try { if (stmt != null) stmt.close(); } catch (Exception e) {}; try { if (conn != null) conn.close(); } catch (Exception e) {}; } The question is if the closing of the connection does the job or if it leaves some resources in use.

    Read the article

  • adding elements in to the doubly linked list

    - by user329820
    Hi this is my code for main class and doubly linked class and node class but when I run the program ,in the concole will show this"datastructureproject.DoublyLinkedList@19ee1ac" instead of the random numbers .please help me thanks! main class: public class Main { public static int getRandomNumber(double min, double max) { Random random = new Random(); return (int) (random.nextDouble() * (max - min) + min); } public static void main(String[] args) { int j; int i = 0; i = getRandomNumber(10, 10000); DoublyLinkedList listOne = new DoublyLinkedList(); for (j = 0; j <= i / 2; j++) { listOne.add(getRandomNumber(10, 10000)); } System.out.println(listOne); } } doubly linked list class: public class DoublyLinkedList { private Node head ; private Node tail; private long size = 0; public DoublyLinkedList() { head= new Node(0, null, null); tail = new Node(0, head, null); } public void add(int i){ head.setValue(i); Node newNode = new Node(); head.setNext(newNode); newNode.setPrev(head); newNode = head; } } and the node class is like the class that you have seen before (Node prev,Node next,int value)

    Read the article

  • JPA atomic query/save for multithreaded app

    - by TofuBeer
    I am in the midst of changing my JPA code around to make use of threads. I have a separate entity manager and transaction for each thread. What I used to have (for the single threaded environment) was code like: // get object from the entity manager X x = getObjectX(jpaQuery); if(x == null) { x = new X(); x.setVariable(foo); entityManager.persist(x); } With that code in the multi threaded environment I am getting duplicate keys since, I assume, getObjectX returns null for a thread, then that thread is swapped out, the next thread calls getObjextX, also getting null, and then both threads will create and persist a new X(). Short of adding in synchronization, is there an atomic way to get/save-if-doesn't-exist a value with JPA or should I rethink my approach EDIT: I am using the latest Eclipselink and MySql 5.1

    Read the article

  • Creating parameterized type object using annonymous class

    - by Andrei Fierbinteanu
    This might be a stupid question, but I just saw a question asking how to create a Type variable for a generic type. The consensus seemed to be that you should have a dummy method returning that type, and then use reflection to get it (in this case he wanted Map<String, String>). Something like this : public Map<String, String> dummy() { throw new Error(); } Type mapStringString = Class.forName("ThisClass").getMethod("dummy").getGenericReturnType(); My question is, not having used reflection that much, couldn't you just do something like: Type mapStringString = new ParameterizedType() { public Type getRawType() { return Map.class; } public Type getOwnerType() { return null; } public Type[] getActualTypeArguments() { return new Type[] { String.class, String.class }; } }; Would this work? If not, why not? And what are some of the dangers/problems if it does (besides being able to return some Type like Integer<String> which is obviously not possible.

    Read the article

  • Automatically selecting and creating class objects

    - by Omin
    Lets say that we have a box class: class Box { private int width; private int height; //Box Constructor public Box( int height ) { this.height = height; width = 450; } } and a series of Box objects in our main: Box Box1 = new Box(147); Box Box2 = new Box(178); Box Box3 = new Box(784); Is there a way to use a "for" loop to go through these objects? Also, how would you make the computer create class objects for us? eg. create 10 objects using: for( int i=0; i>10; i++) { //method }

    Read the article

  • Eclipselink and update trigger on multiple access to the database

    - by Raven
    Hi, in my project I have a database which many clients connect to. Concurrent access and writing works well. The problem now is not to reload the data every second from the database to always have the current status of the data. Does Eclipselink provide a trigger mechanism on (automatically?) reload the data if the database is changed? How would one use this trigger? Thanks!

    Read the article

  • Tomcat does not persist UserPrinciple during restart

    - by mabuzer
    How to force Tomcat to serialize UserPrinciple so that the user is kept logged in when Tomcat has restarted? Right now the user has to login again everytime. Added the following lines into web-app context.xml: <Manager className="org.apache.catalina.session.PersistentManager"> <Store className="org.apache.catalina.session.FileStore"/> </Manager> but still I see login page after Tomcat restart, I use Tomcat 6.0.26

    Read the article

  • Fill a array with List data

    - by marionmaiden
    How can I fill a array with the data provided by one List? For example, I have a List with Strings: List l = new ArrayList<String>(); l.add("a"); l.add("b"); l.add("c"); then I want to copy this data into a String array: String[] array = ?

    Read the article

  • JUnit : Is there a way to skip a test belonging to a Test class's parent?

    - by Jon
    I have two classes: public abstract class AbstractFoobar { ... } and public class ConcreteFoobar extends AbstractFoobar { ... } I have corresponding test classes for these two classes: public class AbstractFoobarTest { ... } and public class ConcreteFoobarTest extends AbstractFoobarTest { ... } When I run ConcreteFoobarTest (in JUnit), the annotated @Test methods in AbstractFoobarTest get run along with those declared directly on ConcreteFoobarTest because they are inherited. Is there anyway to skip them?

    Read the article

  • custom ListView --Null pointer exception

    - by raghs
    this code throws a Null pointer exception. It was thrown by getChildAt(i). The getCount() returns the number of items in listView. But getChildAt(i) returns only if item is present in current list view. For example in a scrollable list view assume that there are 20 items. The getCount() returns 20. But getChildAt(20) returns null. Because it doesnot fit in listview. How to solve this problem?? int i,j=object.getCount(); View v=getListView(); CheckBox chk=null; for(i=0;i<j;i++) { chk=((CheckBox)((ViewGroup) v).getChildAt(i).findViewById(R.id.checkBox1)); if(chk.isChecked()) { //download the contents to specific folder in sd card } }

    Read the article

  • jsf and eclipse setup. Lib in Explorer is different than lib in tomcat. How come?

    - by user384706
    Hi, I am starter in JSF2.0, and I have a question related to Eclipse (I am using Helios). 1)I create a Dynamic Project 2)I add JSF project facet. 3)I choose JSF user library (I have created it using MyFaces) All ok so far. I notice though that in the Project Explorer in WebContent/WEB-INF/lib the lib directory is empty instead of having MyFaces jars. The application works fine though. I looked into this and the jars are actually being placed in the corresponding lib directory of the app deployed under wtpwebapps of the Tomcat instance of eclipse in the .pluggins directory. Ok, it works but IMHO it is incorrect to have the Project Explorer inconsistent with the directories actually deployed. I.e. lib is shown empty in Project Explorer but with jars under wtpwebapps. Am I wrong to dislike this inconsistency? Is this how it should work or am I doing something wrong in the way I am setting my project? Thanks!

    Read the article

  • How can I get an error or a warning from a PreparedStatement?

    - by Geo
    I had an update like this: update table set col1=?,col2=?,col3=? where col4=?; and I filled it up like this: statement.setString(1,"some_value"); statement.setString(2,"some_value"); statement.setString(3,"some_value"); and I forgot to add a fourth value.I did a executeUpdate and of course nothing happened to the database. I spent about 1 hour debugging it, to see where it goes wrong. I then modified my code to print the SQLWarning object returned by the getWarnings method. It always returned null. I even modified the code to the buggy state it was, before I set the fourth parameter, and still no warning. Does anyone know how one can get an error/warning? If it matters, my Connection is set to autoCommit.

    Read the article

  • SOAP logging axis2

    - by salcin
    Using axis1 it is possible to log incoming/outgoing soap messages by adding logging on HTTPSender in log4j.properties. After migrating to axis2 (version 1.4.1) I have a hard time figuring out how to accomplish the same kind of logging. I have tried to add logging on the axis2 package and org.apache.commons.httpclient but no logging is provided. Any ideas? TIA

    Read the article

  • Image gets slightly erased on SWT/Windows

    - by zvikico
    I have an Eclipse plugin which includes a view. The view has several icons in the toolbar. I'm experiencing a very strange problem: on Windows, in some occasions (after prolonged use), one of the icons gets slightly erased. This does not happen on other platforms. This looks like a memory leak or some other resource misuse, but I just can't figure out where. The rest of the icons, which are initialized and used in the exact same manner are not affected. I tried working with Sleak, but I really don't see anything out of the ordinary. Any help would be appreciated.

    Read the article

  • how to implement a callback in runnable to update other swing class

    - by wizztjh
    I have a thread like this public class SMS { class Read implements Runnable { Read(){ Thread th = new Thread(this); th.start(); } @Override public void run() { // TODO Auto-generated method stub while (true){ Variant SMSAPIReturnValue = SMSAPIJava.invoke("ReadSMS"); if (SMSAPIReturnValue.getBoolean()){ String InNumber = SMSAPIJava.getPropertyAsString("MN"); String InMessage = SMSAPIJava.getPropertyAsString("MSG"); } } } } } How do I update the message to another GUI class in the same package(I understand how to put nested class to another package ....). Should I implement a callback function in SMS class? But how? Or should I pass in the Jlabel into the class?

    Read the article

  • Iterate over a list and put data in hashmap

    - by sarah
    I am having a list where i need to loop over it and put its data in hashmap,i am using this approach for(int i=0;i<list.size();i++) { HashMap hMap=new HashMap(); hMap.put("Data", list); } But when i need to read the value from hMap i am doing in this way Collection c = hMap.values(); Iterator itr = c.iterator(); while(itr.hasNext()) { System.out.println("next val is--"+itr.next()); } next vali is--- is printed in com.bean.xyz@23032bc[id=1] format ,i need the exact data,how will i do this ?

    Read the article

  • Best cross-language analyzer to use with lucene index

    - by Halirob
    Hello, I'm looking for feedback on which analyzer to use with an index that has documents from multiple languages. Currently I am using the simpleanalyzer, as it seems to handle the broadest amount of languages. Most of the documents to be indexed will be english, but there will be the occasional double-byte language indexed as well. Are there any other suggestions or should I just stick with the simpleanalyzer. Thanks

    Read the article

  • graphing amplitude

    - by John
    I was wondering if someone could point me to a good tutorial or show me how to graph the amplitude from a bytearray. The audio format I am using is: ULAW 8000.0 Hz, 8 bit, mono, 1 bytes/frame.

    Read the article

  • Eclipse Plugin: Enablement of an Action based on the current selection - before the

    - by Itay
    Here's my problem: I am using the org.eclipse.ui.popupMenus extension point for adding a sub-menu whose Action that is bounded to the following class: public class MyAction implements IObjectActionDelegate { private Logic logic = Logic.getInstance(); // Singleton public void setActivePart(IAction a, IWorkbenchPart targetPart) { // Nothing here } public void run(IAction a) { // Do something... } public void selectionChanged(IAction a, ISelection s) { a.setEnabled(logic.isEnabled(s)); } } This action is working correctly in most cases (including the call a.setEnabled() in selectionChanged()). My problem at the very first time my action is being invoked. The selectionChanged method is called only after the menu item has been displayed (and not when the user has made the selection) which means that the call to a.setEnabled() will have no affect. Any ideas on how to make my action receive selectionChanged() notifications even before the fist time it is being invoked?

    Read the article

  • DefaultStyledDocument.styleChanged(Style style) may not run in a timely manner?

    - by Paul Reiners
    I'm experiencing an intermittent problem with a class that extends javax.swing.text.DefaultStyledDocument. This document is being sent to a printer. Most of the time the formatting of the document looks correct, but once in a while it doesn't. It looks like some of the changes in the formatting have not been applied. I took a look at the DefaultStyledDocument.styleChanged(Style style) code: /** * Called when any of this document's styles have changed. * Subclasses may wish to be intelligent about what gets damaged. * * @param style The Style that has changed. */ protected void styleChanged(Style style) { // Only propagate change updated if have content if (getLength() != 0) { // lazily create a ChangeUpdateRunnable if (updateRunnable == null) { updateRunnable = new ChangeUpdateRunnable(); } // We may get a whole batch of these at once, so only // queue the runnable if it is not already pending synchronized(updateRunnable) { if (!updateRunnable.isPending) { SwingUtilities.invokeLater(updateRunnable); updateRunnable.isPending = true; } } } } /** * When run this creates a change event for the complete document * and fires it. */ class ChangeUpdateRunnable implements Runnable { boolean isPending = false; public void run() { synchronized(this) { isPending = false; } try { writeLock(); DefaultDocumentEvent dde = new DefaultDocumentEvent(0, getLength(), DocumentEvent.EventType.CHANGE); dde.end(); fireChangedUpdate(dde); } finally { writeUnlock(); } } } Does the fact that SwingUtilities.invokeLater(updateRunnable) is called, rather than invokeAndWait(updateRunnable), mean that I can't count on my formatting changes appearing in the document before it is rendered? If that is the case, is there a way to ensure that I don't proceed with rendering until the updates have occurred?

    Read the article

< Previous Page | 976 977 978 979 980 981 982 983 984 985 986 987  | Next Page >