Search Results

Search found 46178 results on 1848 pages for 'java home'.

Page 876/1848 | < Previous Page | 872 873 874 875 876 877 878 879 880 881 882 883  | Next Page >

  • Is ActiveMQ unreliable?

    - by user122991
    Hello, We have been using ActiveMQ 5.2 in our distributed enterprise application for about 3 months. During that time, we have experienced debilitating failures at least twice weekly. In particular, we see: 1) Topic publisher has its connection arbitrarily closed and experiences EOF on attempt to publish. Note well that this issue is not a function of some timeout. It does not correlate reliably with any inactivity. 2) Queue listeners never receive message. Message simply sits on Queue. 2) is much rarer (hardly ever) than 1). In both cases, the failures are highly intermittent-- they cannot be reliably reproduced through any testing usage pattern. Also, there are no errors or warning in the AMQ logs. Have others experienced similar problems? Is there an opinion that some other JMS provider is more reliable? thanks, Joe

    Read the article

  • Inheriting the main method

    - by Eric
    I want to define a base class that defines a main method that instantiates the class, and runs a method. There are a couple of problems though. Here is the base class: public abstract class Strategy { abstract void execute(SoccerRobot robot); public static void main(String args) { Strategy s = new /*Not sure what to put here*/(); s.execute(new SoccerRobot()) } } And here is an example derived class: public class UselessStrategy { void execute(SoccerRobot robot) { System.out.println("I'm useless") } } It defines a simple execute method, which should be called in a main method upon usage as a the main application. However, in order to do so, I need to instantiate the derived class from within the base class's main method. Which doesn't seem to be possible. I'd rather not have to repeat the main method for every derived class, as it feels somewhat unnessary. Is there a right way of doing this?

    Read the article

  • use of system.exit(0)

    - by Warrior
    public class WrapperTest { static { print(10); } static void print(int x) { System.out.println(x); System.exit(0); } } In the above code System.exit(0) is used to stop the program. What argument does that method take? Why do we gave it as 0. Can anyone explain the concept?Thanks.

    Read the article

  • Array not showing in Jlist but filled in console

    - by OVERTONE
    Hey there. been a busy debugger today. ill give ths short version. ive made an array list that takes names from a database. then i put the contents of the arraylist into an array of strings. now i want too display the arrays contents in a JList. the weird thing is it was working earlier. and ive two methods. ones just a little practice too make sure i was adding to the Jlist correctly. so heres the key codes. this is the layout of my code. variables constructor methods in my variables i have these 3 defined String[] contactListNames = new String[5]; ArrayList<String> rowNames = new ArrayList<String>(); JList contactList = new JList(contactListNames); simple enough. in my constructor i have them again. contactListNames = new String[5]; contactList = new JList(contactListNames); //i dont have the array list defined though. printSqlDetails(); // the prinSqldetails was too make sure that the connectionw as alright. and its working fine. fillContactList(); // this is the one thats causing me grief. its where all the work happens. // fillContactListTest(); // this was the tester that makes sure its adding to the list alright. heres the code for fillContactListTest() public void fillContactListTest() { for(int i = 0;i<3;i++) { try { String contact; System.out.println(" please fill the list at index "+ i); Scanner in = new Scanner(System.in); contact = in.next(); contactListNames[i] = contact; in.nextLine(); } catch(Exception e) { e.printStackTrace(); } } } heres the main one thats supposed too work. public void fillContactList() { int i =0; createConnection(); ArrayList<String> rowNames = new ArrayList<String>(); try { Statement stmt = conn.createStatement(); ResultSet namesList = stmt.executeQuery("SELECT name FROM Users"); try { while (namesList.next()) { rowNames.add(namesList.getString(1)); contactListNames =(String[])rowNames.toArray(new String[rowNames.size()]); // this used to print out contents of array list // System.out.println("" + rowNames); while(i<contactListNames.length) { System.out.println(" " + contactListNames[i]); i++; } } } catch(SQLException q) { q.printStackTrace(); } conn.commit(); stmt.close(); conn.close(); } catch(SQLException e) { e.printStackTrace(); } } i really need help here. im at my wits end. i just cant see why the first method would add to the JList no problem. but the second one wont. both the contactListNames array and array list can print fine and have the names in them. but i must be transfering them too the jlist wrong. please help p.s im aware this is long. but trust me its the short version.

    Read the article

  • Why does DataInputStream not support integers?

    - by Jason
    I need to read in a list of numbers from a file, none of which are larger than 32767. Originally I was going to use the Scanner class to pull in the data, then I read about DataInputStream. This would work well for me, except that according to the API, it supports all primitive variables EXCEPT ints! Listed are longs, shorts, bytes, chars, booleans, ect, but no ints. I have no need for double precision from the incoming data. Is this a deliberate or unintentional oversight?

    Read the article

  • Adding label and text box control to GUI

    - by Mike
    I would like to know what code to insert and where to add a simple label that can just say the word "Label" and a input text box that I can enter a number. public CalculateDimensions() { JTabbedPane Tab = new JTabbedPane(); JPanel jplInnerPanel1 = createInnerPanel("First Tab"); Tab.addTab("One", jplInnerPanel1); Tab.setSelectedIndex(0); JPanel jplInnerPanel2 = createInnerPanel("Second Tab"); Tab.addTab("Two", jplInnerPanel2); JPanel jplInnerPanel3 = createInnerPanel("Third Tab"); Tab.addTab("Three", jplInnerPanel3); JPanel jplInnerPanel4 = createInnerPanel("Fourth Tab"); Tab.addTab("Four", jplInnerPanel4); JPanel jplInnerPanel5 = createInnerPanel("Fifth Tab"); Tab.addTab("Five", jplInnerPanel5); setLayout(new GridLayout(1, 1)); add(Tab); } protected JPanel createInnerPanel(String text) { JPanel jplPanel = new JPanel(); JLabel jlbDisplay = new JLabel(text); jlbDisplay.setHorizontalAlignment(JLabel.CENTER); jplPanel.setLayout(new GridLayout(1, 1)); jplPanel.add(jlbDisplay); return jplPanel; } public static void main(String[] args) { JFrame frame = new JFrame("Calculations"); frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); frame.getContentPane().add(new CalculateDimensions(), BorderLayout.CENTER); frame.setSize(400, 400); frame.setVisible(true); } }

    Read the article

  • Best way to style GWT widgets in a library

    - by helios
    I'm developing some widgets into a library for internal use at the company I work for. I don't know what's the recommended way to style the widgets. There are at least these ways: use Widget.setPrimaryStyleName and let the user provide an external css. We use maven archetypes to build applications so we can provide default styles. Anyway I don't like it very much. use the GWT 2.0 CssResourceBundle. So we can compile the CSS into the module and it will be optimized (and it can be browser-dependant too). provide a module with the styling. Something like the default GWT themes. But I don't know how exactly this works. I want to: make the components as cohesive as I can (don't depend on externally included css's) leave open the door to modify styles (if I want to change the way some widget looks in a concrete application). What's your experience in this subject?

    Read the article

  • jboss cache as hibernate 2nd level - cluster node doesn't persist replicated data

    - by Sergey Grashchenko
    I'm trying to build an architecture basically described in user guide http://www.jboss.org/file-access/default/members/jbosscache/freezone/docs/3.2.1.GA/userguide_en/html/cache_loaders.html#d0e3090 (Replicated caches with each cache having its own store.) but having jboss cache configured as hibernate second level cache. I've read manual for several days and played with the settings but could not achieve the result - the data in memory (jboss cache) gets replicated across the hosts, but it's not persisted in the datasource/database of the target (not original) cluster host. I had a hope that a node might become persistent at eviction, so I've got a cache listener and attached it to @NoveEvicted event. I found that though I could adjust eviction policy to fully control it, no any persistence takes place. Then I had a though that I could try to modify CacheLoader to set "passivate" to true, but I found that in my case (hibernate 2nd level cache) I don't have a way to access a loader. I wonder if replicated data persistence is possible at all by configuration tuning ? If not, will it work for me to create some manual peristence in CacheListener (I could check whether the eviction event is local, and if not - persist it to hibernate datasource somehow) ? I've used mvcc-entity configuration with the modification of cacheMode - set to REPL_ASYNC. I've also played with the eviction policy configuration. Last thing to mention is that I've tested entty persistence and replication in project that has been generated with Seam. I guess it's not important though.

    Read the article

  • Missing JAXB classes from XMLschema.xsd

    - by XLR
    Hi, I'm working on a xml schema resolver and I'm using JAXB with XMLSchema.xsd. I experience problems with JAXB, because I don't get classes for all the top level elements. For example for <xs:element name="maxLength" id="maxLength" type="xs:numFacet"> I do not get a class MaxLength or anything like that. Only NumFacet exists. Anyone else experienced that and could please help me? Cheers, XLR

    Read the article

  • Restore previously serialized JFrame-object, how?

    - by elementz
    Hi all. I have managed to serialize my very basic GUI-object containing a JTextArea and a few buttons to a file 'test.ser'. Now, I would like to completely restore the previously saved state from 'test.ser', but seem to have a misconception of how to properly deserialize an objects state. The class MyFrame creates the JFrame and serializes it. public class MyFrame extends JFrame implements ActionListener { // Fields JTextArea textArea; String title; static MyFrame gui = new MyFrame(); private static final long serialVersionUID = 1125762532137824262L; /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub gui.run(); } // parameterless default contructor public MyFrame() { } // constructor with title public MyFrame(String title) { } // creates Frame and its Layout public void run() { JFrame frame = new JFrame(title); JPanel panel_01 = new JPanel(); JPanel panel_02 = new JPanel(); JTextArea textArea = new JTextArea(20, 22); textArea.setLineWrap(true); JScrollPane scrollPane = new JScrollPane(textArea); scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED); panel_01.add(scrollPane); // Buttons JButton saveButton = new JButton("Save"); saveButton.addActionListener(this); JButton loadButton = new JButton("Load"); loadButton.addActionListener(this); panel_02.add(loadButton); panel_02.add(saveButton); // Layout frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.getContentPane().add(BorderLayout.CENTER, panel_01); frame.getContentPane().add(BorderLayout.SOUTH, panel_02); frame.setSize(300, 400); frame.setVisible(true); } /* * */ public void serialize() { try { ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("test.ser")); oos.writeObject(gui); oos.close(); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } } public void actionPerformed(ActionEvent ev) { System.out.println("Action received!"); gui.serialize(); } } Here I try to do the deserialization: public class Deserialize { static Deserialize ds; static MyFrame frame; public static void main(String[] args) { try { ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.ser")); frame = (MyFrame) ois.readObject(); ois.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } Maybe somebody could point me into the direction where my misconception is? Thx in advance!

    Read the article

  • Should I create protected constructor for my singleton classes?

    - by Vijay Shanker
    By design, in Singleton pattern the constructor should be marked private and provide a creational method retuning the private static member of the same type instance. I have created my singleton classes like this only. public class SingletonPattern {// singleton class private static SingletonPattern pattern = new SingletonPattern(); private SingletonPattern() { } public static SingletonPattern getInstance() { return pattern; } } Now, I have got to extend a singleton class to add new behaviors. But the private constructor is not letting be define the child class. I was thinking to change the default constructor to protected constructor for the singleton base class. What can be problems, if I define my constructors to be protected? Looking for expert views....

    Read the article

  • How significant are JPA lazy loading performance benefits?

    - by Robert
    I understand that this is highly specific to the concrete application, but I'm just wondering what's the general opinion, or at least some personal experiences on the issue. I have an aversion towards the 'open session in view' pattern, so to avoid it, I'm thinking about simply fetching everything small eagerly, and using queries in the service layer to fetch larger stuff. Has anyone used this and regretted it? And is there maybe some elegant solution to lazy loading in the view layer that I'm not aware of?

    Read the article

  • Hibernate: Walk millions of rows and don't leak memory

    - by Autocracy
    The below code functions, but Hibernate never lets go of its grip of any object. Calling session.clear() causes exceptions regarding fetching a joined class, and calling session.evict(currentObject) before retrieving the next object also fails to free the memory. Eventually I exhaust my heap space. Checking my heap dumps, StatefulPersistenceContext is the garbage collector's root for all references pointing to my objects. public class CriteriaReportSource implements JRDataSource { private ScrollableResults sr; private Object currentObject; private Criteria c; private static final int scrollSize = 10; private int offset = 1; public CriteriaReportSource(Criteria c) { this.c = c; advanceScroll(); } private void advanceScroll() { // ((Session) Main.em.getDelegate()).clear(); this.sr = c.setFirstResult(offset) .setMaxResults(scrollSize) .scroll(ScrollMode.FORWARD_ONLY); offset += scrollSize; } public boolean next() { if (sr.next()) { currentObject = sr.get(0); if (sr.isLast()) { advanceScroll(); } return true; } return false; } public Object getFieldValue(JRField jrf) throws JRException { Object retVal = null; if(currentObject == null) { return null; } try { retVal = PropertyUtils.getProperty(currentObject, jrf.getName()); } catch (Exception ex) { Logger.getLogger(CriteriaReportSource.class.getName()).log(Level.SEVERE, null, ex); } return retVal; } }

    Read the article

  • Eclipse 3.5: Implementing my own context menu for a MultipageEditorPart --> no viewer involved

    - by Patrick
    Hello! :-) In my current RCP-project i use a MultipageEditorPart. It has various pages, with simple SWT composites on it. The composites contain some Text and Combo elements. When the user right clicks onto the editor page, I want a context menu to open. This menu holds a command for creating a new editor page, with a composite on it. The command is already working, but I'm quite clueless about how to implement the context menu for the editor. Can someone help with this?

    Read the article

  • Lucene setboost doesn't work

    - by Keven
    Hi all, OUr team just upgrade lucene from 2.3 to 3.0 and we are confused about the setboost and getboost of document. What we want is just set a boost for each document when add them into index, then when search it the documents in the response should have different order according to the boost I set. But it seems the order is not changed at all, even the boost of each document in the search response is still 1.0. Could some one give me some hit? Following is our code: String[] a = new String[] { "schindler", "spielberg", "shawshank", "solace", "sorcerer", "stone", "soap", "salesman", "save" }; List strings = Arrays.asList(a); AutoCompleteIndex index = new Index(); IndexWriter writer = new IndexWriter(index.getDirectory(), AnalyzerFactory.createAnalyzer("en_US"), true, MaxFieldLength.LIMITED); float i = 1f; for (String string : strings) { Document doc = new Document(); Field f = new Field(AutoCompleteIndexFactory.QUERYTEXTFIELD, string, Field.Store.YES, Field.Index.NOT_ANALYZED); doc.setBoost(i); doc.add(f); writer.addDocument(doc); i += 2f; } writer.close(); IndexReader reader2 = IndexReader.open(index.getDirectory()); for (int j = 0; j < reader2.maxDoc(); j++) { if (reader2.isDeleted(j)) { continue; } Document doc = reader2.document(j); Field f = doc.getField(AutoCompleteIndexFactory.QUERYTEXTFIELD); System.out.println(f.stringValue() + ":" + f.getBoost() + ", docBoost:" + doc.getBoost()); doc.setBoost(j); }

    Read the article

  • Android Development Eclise - Cant Create a New Android Project - Mac OS

    - by Ben Diamant
    I have an issue creating a new android project using the eclipse wizard, everything worked fine by yesterday. had a few project working. Now, when i press "Finish" on the final step of the wizard it remain open and an empty project with white-marked packages is added to the work branch, I tried to reinstall eclipse and it's sdk+plug, still nothing. Would really appreciate your assistance, Thank you in advance Ben

    Read the article

  • How to use locks/synchronization here

    - by MasterGberry
    I have this code block here and i need to make sure the rankedPlayersWaitingForMatch is synchronized between threads properly. I was going to use synchronize but that i don't think will work here because of the variable being used in the if statement. I read online about final Lock lock = new ReentrantLock(); but I am a bit confused on how to use it in this case properly with the try/finally block. Can I get a quick example? Thanks // start synchronization if (rankedPlayersWaitingForMatch.get(rankedType).size() >= 2) { Player player1 = rankedPlayersWaitingForMatch.get(rankedType).remove(); Player player2 = rankedPlayersWaitingForMatch.get(rankedType).remove(); // end synchronization // ... I don't want this all to be synchronized, just after the first 2 remove() } else { // end synchronization // ... }

    Read the article

  • Ant Tokenizer: Selecting an individual Token

    - by John Oxley
    I have the following ant task: <loadfile property="proj.version" srcfile="build.py"> <filterchain> <striplinecomments> <comment value="#"/> </striplinecomments> <linecontains> <contains value="Version" /> </linecontains> </filterchain> </loadfile> <echo message="${proj.version}" /> And the output is [echo] config ["Version"] = "v1.0.10-r4.2" How do I then use a tokenizer to get only v1.0.10-r4.2, the equivalent of | cut -d'"' -f4

    Read the article

  • Representing element as boolean with JAXB?

    - by Marcus
    We have this XML: <Summary> <ValueA>xxx</ValueA> <ValueB/> </Summary> <ValueB/> will never have any attributes or inner elements. It's a boolean type element - it exists (true) or it doesn't (false). JAXB generated a Summary class with a String valueA member, which is good. But for ValueB, JAXB generated a ValueB inner class and a corresponding member: @XmlElement(name = "ValueB") protected Summary.ValueB valueB; But what I'd like is a boolean member and no inner class: @XmlElement(name = "ValueB") protected boolean valueB; How can you do this? I'm not looking to regenerate the classes, I'd like to just make the code change manually. Update: In line with the accepted answer, we created a new method returning the boolean value conditional on whether valueB == null. As we are using Hibernate, we annotated valueB with @Transient and annotated the boolean getter with Hibernate's @Column annotation.

    Read the article

  • Android How to get position of selected item from gridview without using onclicklistner, using ontouchlistner instead

    - by zonemikel
    I have a gridview, I need to do stuff on motioneven.action_down and do something for motioneven.action_up ... using onclicklistener is great but does not give me this needed functionality. Is there anyway to easily call the gridview and get its selected item in a ontouchlistener ? I've been having limited success with making my own implementation. Its hard to get the right x,y because if i call the child it gives me the x and y relative to the child so a button would be 0,0 to 48,48 but it does not tell you the actual location on the screen relative to the gridview or the screen itself. this is what i've been doing, its partially working so far. Grid.setOnTouchListener(new OnTouchListener() { public boolean onTouch(View v, MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) { int x = (int)event.getX(); int y = (int)event.getY(); int position = 0; int childCount = Grid.getChildCount(); Message msg = new Message(); Rect ButtonRect = new Rect(); Grid.getChildAt(0).getDrawingRect(ButtonRect); int InitialLeft = ButtonRect.left + 10; ButtonRect.offsetTo(InitialLeft, ButtonRect.top); // while(position < childCount){ if(ButtonRect.contains(x,y)){break;} if(ButtonRect.right + ButtonRect.width() > Grid.getWidth()) { ButtonRect.offsetTo(InitialLeft, ButtonRect.bottom);} position++; ButtonRect.offsetTo(ButtonRect.right, ButtonRect.top); } msg.what = position; msg.arg1 = ButtonRect.bottom; msg.arg2 = y; cHandler.sendMessage(msg); }// end if action up if (event.getAction() == MotionEvent.ACTION_UP) { } return false; } });

    Read the article

  • Encountering NullPointerException when trying to add polynoms

    - by Ayler Cruz
    I need to add two polynomials, which is composed of two ints. For example, the coefficient and the exponent 3x^2 would be constructed using 3 and 2 as parameters. I am getting a NullPointerException but I can't figure out why. Any help would be appreciated! public class Polynomial { private Node poly; public Polynomial() { } private Polynomial(Node p) { poly = p; } private class Term { int coefficient; int exponent; private Term(int coefficient, int exponent) { this.coefficient = coefficient; this.exponent = exponent; } } private class Node { private Term data; private Node next; private Node(Term data, Node next) { this.data = data; this.next = next; } } public void addTerm(int coeff, int exp) { Node pointer = poly; if (pointer.next == null) { poly.next = new Node(new Term(coeff, exp), null); } else { while (pointer.next != null) { if (pointer.next.data.exponent < exp) { Node temp = new Node(new Term(coeff, exp), pointer.next.next); pointer.next = temp; return; } pointer = pointer.next; } pointer.next = new Node(new Term(coeff, exp), null); } } public Polynomial polyAdd(Polynomial p) { return new Polynomial(polyAdd(this.poly, p.poly)); } private Node polyAdd(Node p1, Node p2) { if (p1 == p2) { Term adding = new Term(p1.data.coefficient + p2.data.coefficient, p1.data.exponent); p1 = p1.next; p2 = p2.next; return new Node(adding, null); } if (p1.data.exponent > p2.data.exponent) { p2 = p2.next; } if (p1.data.exponent < p2.data.exponent) { p1 = p1.next; } if (p1.next != null && p2.next != null) { return polyAdd(p1, p2); } return new Node(null, null); } }

    Read the article

  • org.apache.commons.httpclient.NameValuePair in post method

    - by pushkins
    I'm writing some code like : PostMethod p = new PostMethod(someurl); ... NameValuePair[] data = { new NameValuePair("name1", "somevalue1"), new NameValuePair("var[3][1]", "10") }; try { hc.executeMethod(p); } ... And that's what I get, when I look at my post in Wireshark: POST /someurl HTTP/1.1 ... type=var&ship%5B3%5D%5B1%5D=10 %5B means [, %5D- ] So the problem is how I can get square brackets in my post?

    Read the article

< Previous Page | 872 873 874 875 876 877 878 879 880 881 882 883  | Next Page >