Search Results

Search found 33297 results on 1332 pages for 'java java ee'.

Page 810/1332 | < Previous Page | 806 807 808 809 810 811 812 813 814 815 816 817  | Next Page >

  • Why does a sub-class class of a class have to be static in order to initialize the sub-class in the

    - by Alex
    So, the question is more or less as I wrote. I understand that it's probably not clear at all so I'll give an example. I have class Tree and in it there is the class Node, and the empty constructor of Tree is written: public class RBTree { private RBNode head; public RBTree(RBNode head,RBTree leftT,RBTree rightT){ this.head=head; this.head.leftT.head.father = head; this.head.rightT.head.father = head; } public RBTree(RBNode head){ this(head,new RBTree(),new RBTree()); } public RBTree(){ this(new RBNode(),null,null); } public class RBNode{ private int value; private boolean isBlack; private RBNode father; private RBTree leftT; private RBTree rightT; } } Eclipse gives me the error: "No enclosing instance of type RBTree is available due to some intermediate constructor invocation" for the "new RBTree()" in the empty constructor. However, if I change the RBNode to be a static class, there is no problem. So why is it working when the class is static. BTW, I found an easy solution for the cunstructor: public RBTree(){ this.head = new RBNode(); } So, I have no idea what is the problem in the first piece of code.

    Read the article

  • Is using the break statement bad practice?

    - by Lchi
    I've been told by professors and peers at my university that using the break statement is bad practice, but through my coursework haven't come up with a great reason why. Those who claim that it is bad say that it's a "get out of jail free card" and that you can always avoid using it. My guesses for why its considered bad would be that you could possibly skip some cleanup code after the break, or similarly exit some control structure in an inconsistent state. Is there any reason why using break is(n't) bad practice?

    Read the article

  • How to sort a key of a map

    - by Tsuna Sawada
    How to sort (any kind of sorting) a key of a map(treemap or hashmap) i have a problem and it goes like this. i have a map that has a key of 27527-683, 27525-1179, 27525-1571, 27525-1813, 27525-4911, 27526-1303, 27526-3641, 27525-3989, 27525-4083, 27525-4670, 27526-4102, 27526-558, 27527-2411, 27527-4342 this is the list of keys and the value for each of the key is a list. now, how can i sort this key in ascending order by number. ex. if i want to sort : 1,2,11,20,31,3,10 i want to have as output is : 1,2,3,10,11,20,31 but when i use the autosort of treemap the output goes : 1,10,11,2,20,3,31 how can i sort it in ascending order by numeric? please help me. i can't think of anymore ways because this is my first time handling map and list

    Read the article

  • Can FileOutputStream() take a relative path as an argument

    - by Ankur
    I am creating a FileOutputStream object. It takes a file or String as an argument in its constructor. My question is, can I give it a relative URL as an argument for the location of a file, it doesn't seem to work, but I am trying to work out if this is possible at all (if not I will stop trying). If it is not possible, how can I (from a servlet) get the absolute path (on the filesystem, not the logical URL) to the current location in such a way that I can pass that to the constructor. Part of my problem is that my dev box is Windows but I will publish this to a Unix box, so the paths cannot be the same i.e. on Windows C:/.... and on unix /usr/...

    Read the article

  • Why does this expression not work? JSF

    - by Nitesh Panchal
    Hello, I have a simple problem on .xhtml page. This expression is not working :- <a href="Photos.jsf?albumId=#{item.albumId}&blogId=#{PhotoAlbumsCommonBean.blogId}"> photos </a> I get this error :- Error Parsing /Common/PhotoAlbums.xhtml: Error Traced[line: 20] The reference to entity "blogId" must end with the ';' delimiter. & is causing some kind of error. Thanks in advance :)

    Read the article

  • Children in Enumeration

    - by marionmaiden
    Hello I have a enumeration for elements in a JTree When I find some specific element in this JTree, I want to check it's children. Do the method children() in a Enumeration check it's grandcildren too? For example, let's supose this JTree, considering the identation as new levels of the tree: Fruits apple grape orange peach pineapple strawberry banana If I get the children of grape, will I have just orange and peach or will I get peach children (pineaple) too?

    Read the article

  • display tag query

    - by sarah
    I have code: <display:table name="sessionScope.allUserslist" id="userList" export="false" pagesize="1"> <display:column title="Select" style="width: 90px;"> <input type="checkbox" name="optionSelected" value="<c:out value='${userList.loginName}'/>"/> </display:column> <display:column property="loginName" sortable="false" title="UserName" paramId="loginName" style="width: 150px; text-align:center" href="./editUser.do?method=editUser"/> <display:column property="role" sortable="false" title="UserRole" paramId="role" style="width: 150px; text-align:center"/> </display:table> On click of login name, I am moving to a new page where I need to get all the of user, I am just getting the name not the role, on click of link I am calling an action where in the method I am trying to read the data from the form using User u=(User)form; u.getRole(); but it's null. Where am I going wrong ?

    Read the article

  • Add 'expand' button to JTree node that has no children?

    - by thedude19
    I'd like to add the 'expand' button to my JTree's nodes to indicate that they are expandable. The catch is that they have no children until the user clicks on them (due to processing that happens in the background). Is there any way I can set a node as a parent or having children without it actually having children? Thanks

    Read the article

  • match elements from two files, how to write the intended format to a new file

    - by user2489612
    I am trying to update my text file by matching the first column to another updated file's first column, after match it, it will update the old file. Here is my old file: Name Chr Pos ind1 in2 in3 ind4 foot 1 5 aa bb cc ford 3 9 bb cc 00 fake 3 13 dd ee ff fool 1 5 ee ff gg fork 1 3 ff gg ee Here is the new file: Name Chr Pos foot 1 5 fool 2 5 fork 2 6 ford 3 9 fake 3 13 The updated file will be like: Name Chr Pos ind1 in2 in3 ind4 foot 1 5 aa bb cc fool 2 5 ee ff gg fork 2 6 ff gg ee ford 3 9 bb cc 00 fake 3 13 dd ee ff Here is my code: #!/usr/bin/env python import sys inputfile_1 = sys.argv[1] inputfile_2 = sys.argv[2] outputfile = sys.argv[3] inputfile1 = open(inputfile_1, 'r') inputfile2 = open(inputfile_2, 'r') outputfile = open(outputfile, 'w') ind = inputfile1.readlines() cm = inputfile2.readlines()[1:] outputfile.write(ind[0]) #add header for i in ind: i = i.split() for j in cm: j = j.split() if j[0] == i[0]: outputfile.writelines(j[0:3] + i[3:]) inputfile1.close() inputfile2.close() outputfile.close() When I ran it, it returned a single column rather than the format i wanted, any suggestions? Thanks!

    Read the article

  • Get enum by it's inner field

    - by zeroed
    Hi! Have enum with inner fields, kind of map. Now I need to get enum by it's inner field. Wrote this: package test; /** * Test enum to test enum =) */ public enum TestEnum { ONE(1), TWO(2), THREE(3); private int number; TestEnum(int number) { this.number = number; } public TestEnum findByKey(int i) { TestEnum[] testEnums = TestEnum.values(); for (TestEnum testEnum : testEnums) { if (testEnum.number == i) { return testEnum; } } return null; } } But it's not very efficient to look up through all enums each time I need to find appropriate instance. Is there any other way to do the same?

    Read the article

  • Removing JPanel from a JFrame in netbeans

    - by jt153
    So, I have several JPanels that contain buttons, labels, etc. that I want to switch between from a main JFrame. Currently I am trying to use the this.add(JPanelname); method and this.remove(JPanelname); with the validate(); and repaint(); methods The problem is it will add the panel to the JFrame but it will not remove it. I am not sure how exactly to go about this and any help would be greatly appreciated.

    Read the article

  • Tower of Hanoi, stop sliding

    - by ArtWorkAD
    Hi, I developed a solution for the Tower of Hanoi problem: public static void bewege(int h, char quelle, char ablage, char ziel) { if(h > 0){ bewege(h - 1, quelle, ziel, ablage); System.out.println("Move "+ h +" from " + quelle + " to " + ziel); bewege(h - 1, ablage, quelle, ziel); } } It works fine. Now i want to limit the number of slides and throw an exception if a certain limit is reached. I tried it with a counter but it does not work: class HanoiNK{ public static void main(String args[]){ Integer n = Integer.parseInt(args[0]); Integer k = Integer.parseInt(args[1]); try{ bewege(k, n, 'A', 'B', 'C'); }catch(Exception e){ System.out.println(e); } } public static void bewege(int c, int h, char quelle, char ablage, char ziel) throws Exception{ if(h > 0){ if(counter != 0){ bewege(c, h - 1, quelle, ziel, ablage); c--; System.out.println("Move "+ h +" from " + quelle + " to " + ziel); bewege(c, h - 1, ablage, quelle, ziel); c--; }else{ throw new Exception("stop sliding"); } } } } The exception is never thrown. Any ideas?

    Read the article

  • Automatically copy new Jar file to Tomcat project WEB-INF/lib folder

    - by The D Williams
    I am developing a Tomcat app (actually it's a Red5 app, but this is effectively the same). This contains the usual /WebContent/WEB-INF/lib folder, which is where I locate the various jars it uses. Recently, I pulled a package out of my app project, and converted into a separate Jar project which was then released as open source (this resides in the same workspace). What I want, is that when I build my Tomcat app, that Eclipse automatically pulls the latest version of the Jar I have built into its /WebContent/WEB-INF/lib folder. This is the behaviour you get with .NET when you reference one project from another, and I guess this is why I was expecting to find some way of doing it. At the moment, I have to manually copy/paste the Jar across each time I build it. Of course, ideally when I build my Tomcat app it would automatically detect if the Jar project was up-to-date too, and build it if not. Any suggestions most gratefully received.

    Read the article

  • Hibernate updating records and implementing listeners : getting only required attribute values for event.getOldState()

    - by Narendra
    Hi All, I am using Hibernate 3 as my persistence framework. Below is the sample hbm file I am using. <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.test.User" table="user"> <meta attribute="implements">com.test.dao.interfaces.IEntity</meta> <id name="key" type="long" column="user_key"> <generator class="increment" /> </id> <property name="userName" column="user_name" not-null="true" type="string" /> <property name="password" column="password" not-null="true" type="string" /> <property name="firstName" column="first_name" not-null="true" type="string" /> <property name="lastName" column="last_name" not-null="true" type="string" /> <property name="createdDate" column="created_date" not-null="true" type="timestamp" insert="false" update="false" /> <property name="createdBy" column="created_by" not-null="true" type="string" update="false" /> </class> </hibernate-mapping> I am added a post-update listener. What it will do is if there any updations perfomed on User then it will be invoked and cahnges will be inserted to audit table. Below is the sample implementation for postupdate event. public void onPostUpdate(PostUpdateEvent event) { LogHelper.info(logger, "Begin - onPostUpdate " + event.getEntity().getClass().getSimpleName()); if (!this.checkForAudit(event.getEntity().getClass().getSimpleName())) { // check do we need to audit it. } // Get Attribute Names String[] attrNames = event.getPersister().getEntityMetamodel() .getPropertyNames(); Object[] oldobjectValue = c Object[] newObjectValue = event.getState(); this.auditDetailsEvent(attrNames, oldobjectValue, newObjectValue); LogHelper.info(logger, "End - onPostUpdate"); // return false; } Here is my requirement. event.getPersister().getEntityMetamodel() .getPropertyNames(); or event.getOldState(); or event.getState(); must return attribute names or value which i can update or insert. Is there any way to control the return values of above one's. Pleas help me on this regard. Thanks, Narendra

    Read the article

  • BigDecimal, division & MathContext - very strange behaviour

    - by blackliteon
    CentOs 5.4, OpenJDK Runtime Environment (build 1.6.0-b09) MathContext context = new MathContext(2, RoundingMode.FLOOR); BigDecimal total = new BigDecimal("200.0", context); BigDecimal goodPrice = total.divide(BigDecimal.valueOf(3), 2, RoundingMode.FLOOR); System.out.println("divided price=" + goodPrice.toPlainString()); // prints 66.66 BigDecimal goodPrice2 = total.divide(BigDecimal.valueOf(3), new MathContext(2, RoundingMode.FLOOR)); System.out.println("divided price2=" + goodPrice2.toPlainString()); // prints 66 BUG ?

    Read the article

  • Returning values from Swing using invokeAndWait

    - by Joonas Pulakka
    I've been using the following approach to create components and return values from Swing to/from outside the EDT. For instance, the following method could be an extension to JFrame, to create a JPanel and add it to the parent JFrame: public JPanel threadSafeAddPanel() { final JPanel[] jPanel = new JPanel[1]; try { EventQueue.invokeAndWait(new Runnable() { public void run() { jPanel[0] = new JPanel(); add(jPanel[0]); } }); } catch (InterruptedException ex) { } catch (InvocationTargetException ex) { } return jPanel[0]; } The local 1-length array is used to transfer the "result" from inside the Runnable, which is invoked in the EDT. Well, it looks "a bit" hacky, and so my questions: Does this make sense? Is anybody else doing something like this? Is the 1-length array a good way of transferring the result? Is there an easier way to do this?

    Read the article

  • Server Emulator Design Pattern

    - by adisembiring
    I wanna build server socket emulator, but I want implement some design pattern there. I will described my case study that I have simplified like these: My Server Socket will always listen client socket. While some request message come from the client socket, the server emulator will response the client through the socket. the response is response code. '00' will describe request message processed successfully, and another response code expect '00' will describe there are some error while processing the message request. IN the server there are some UI, this UI contain check response parameter such as. response code timeout interval While the server want to response the client message, the response code taken from input parameter response form UI check the timeout interval, it will create sleep thread and the interval taken from timeout interval input from UI. I have implement the function, but I create it in one class. I feel it so sucks. Can you suggest me what class / interface that I must create to refactor my code.

    Read the article

  • convert pixels into image

    - by Zeta Op
    what i am trying to do is to convert a pixel from a video cam, into an image to expalin it better imagine a 3d model so.. the pixels would be each polying, and i want to do is to conver each polyigon into an image. what i have so far is this ** import processing.video.*; PImage hoja; Capture cam; boolean uno, dos, tres, cuatro; import ddf.minim.*; Minim minim; AudioPlayer audio; float set; void setup() { //audio minim = new Minim(this); // audio = minim.loadFile("audio"); // audio.loop(); // uno=false; dos=false; tres=false; cuatro=true; size(640, 480); hoja=loadImage("hoja.gif"); cam = new Capture(this, width, height); cam.start(); } void draw() { if (cam.available() == true) { cam.read(); if (uno==true) { filtroUno(); image(cam, 0, 0, 640, 480); } if (dos==true) { filtroDos(); } if(tres==true){ filtroTres(); } if(cuatro==true){ filtroCuatro(); image(cam, set, 0,640,480); } } // The following does the same, and is faster when just drawing the image // without any additional resizing, transformations, or tint. //set(0, 0, cam); } void filtroUno() { cam.loadPixels(); hoja.loadPixels(); for (int i=0;i<cam.pixels.length;i++) { if (brightness(cam.pixels[i])>110) { cam.pixels[i]=color(0, 255, 255); } else { cam.pixels[i]=color(255, 0, 0); } } for (int i=0;i<cam.width;i+=10) { for (int j=0;j<cam.height;j+=10) { int loc=i+(j*cam.width); if (cam.pixels[loc]==color(255, 0, 0)) { for (int x=i;x<i+10;x++) { for (int y=j;y<j+10;y++) { // println("bla"); int locDos=i+(j*cam.width); cam.pixels[locDos]=hoja.get(x, y); } } } } } cam.updatePixels(); } ** the broblem is that each pixel is creating me a matrix, so.. is not recreating what id that to do. i had the method filtroUno but it wasn't showing ok.. and was the result void filtroUno() { cam.loadPixels(); hoja.loadPixels(); for (int i=0;i<cam.pixels.length;i++) { if (brightness(cam.pixels[i])>110) { cam.pixels[i]=color(0, 255, 255); } else { cam.pixels[i]=color(255, 0, 0); } } for (int i=0;i<cam.width;i+=10) { for (int j=0;j<cam.height;j+=10) { int loc=i+j*hoja.width*10; if (cam.pixels[loc]==color(255, 0, 0)) { for (int x=i;x<i+10;x++) { for (int y=j;y<j+10;y++) { // println("bla"); int locDos=x+y*hoja.height*10; cam.pixels[locDos]=hoja.get(x, y); } } } } } cam.updatePixels(); } i hope you can help me thanks note: each red pixel should be the gif image the imge size is 10x10

    Read the article

  • Panel is not displaying in JFrame

    - by mallikarjun
    I created a chat panel and added to Jframe but the panel is not displaying. But my sop in the chat panel are displaying in the console. Any one please let me know what could be the problem My Frame public class MyFrame extends JFrame { MyPanel chatClient; String input; public MyFrame() { input = (String)JOptionPane.showInputDialog(null, "Name:", "Connect to chat server", JOptionPane.QUESTION_MESSAGE, null,null, "Test"); input=input.trim(); chatClient = new MyPanel("localhost",input); setVisible(true); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); add(chatClient); } public static void main(String...args){ new MyFrame(); } } MyPanel: public class MyPanel extends JPanel{ ChatClient chatClient; public MyPanel(String host, String uid) { chatClient= new ChatClient(host,uid); add(chatClient.getChatPanel()); this.setVisible(true); } } chat panel: public class ChatClient { Client client; String name; ChatPanel chatPanel; String hostid; public ChatClient(String host,String uid){ client = new Client(); client.start(); System.out.println("in constructor"); Network.register(client); client.addListener(new Listener(){ public void connected(Connection connection){ System.out.println("in client connected method"); Network.RegisterName registerName = new Network.RegisterName(); registerName.name=name; client.sendTCP(registerName); } public void received(Connection connection,Object object){ System.out.println("in client received method"); if (object instanceof Network.UpdateNames) { Network.UpdateNames updateNames = (Network.UpdateNames)object; //chatFrame.setNames(updateNames.names); System.out.println("got it message"); return; } if (object instanceof Network.ChatMessage) { Network.ChatMessage chatMessage = (Network.ChatMessage)object; //chatFrame.addMessage(chatMessage.text); System.out.println("send it message"); return; } } }); // end of listner name=uid.trim(); hostid=host.trim(); chatPanel = new ChatPanel(hostid,name); chatPanel.setSendListener(new Runnable(){ public void run(){ Network.ChatMessage chatMessage = new Network.ChatMessage(); chatMessage.chatMessage=chatPanel.getSendText(); client.sendTCP(chatMessage); } }); new Thread("connect"){ public void run(){ try{ client.connect(5000, hostid,Network.port); }catch(IOException e){ e.printStackTrace(); } } }.start(); }//end of constructor static public class ChatPanel extends JPanel{ CardLayout cardLayout; JList messageList,nameList; JTextField sendText; JButton sendButton; JPanel topPanel,bottomPanel,panel; public ChatPanel(String host,String user){ setSize(600, 200); this.setVisible(true); System.out.println("Chat panel "+host+"user: "+user); { panel = new JPanel(new BorderLayout()); { topPanel = new JPanel(new GridLayout(1,2)); panel.add(topPanel); { topPanel.add(new JScrollPane(messageList=new JList())); messageList.setModel(new DefaultListModel()); } { topPanel.add(new JScrollPane(nameList=new JList())); nameList.setModel(new DefaultListModel()); } DefaultListSelectionModel disableSelections = new DefaultListSelectionModel() { public void setSelectionInterval (int index0, int index1) { } }; messageList.setSelectionModel(disableSelections); nameList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); } { bottomPanel = new JPanel(new GridBagLayout()); panel.add(bottomPanel,BorderLayout.SOUTH); bottomPanel.add(sendText=new JTextField(),new GridBagConstraints(0,0,1,1,1,0,GridBagConstraints.CENTER,GridBagConstraints.BOTH,new Insets(0,0,0,0),0,0)); bottomPanel.add(sendButton=new JButton(),new GridBagConstraints(1,0,1,1,0,0,GridBagConstraints.CENTER,0,new Insets(0,0,0,0),0,0)); } } sendText.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ sendButton.doClick(); } }); } public void setSendListener (final Runnable listener) { sendButton.addActionListener(new ActionListener() { public void actionPerformed (ActionEvent evt) { if (getSendText().length() == 0) return; listener.run(); sendText.setText(""); sendText.requestFocus(); } }); } public String getSendText () { return sendText.getText().trim(); } public void setNames (final String[] names) { EventQueue.invokeLater(new Runnable(){ public void run(){ DefaultListModel model = (DefaultListModel)nameList.getModel(); model.removeAllElements(); for(String name:names) model.addElement(name); } }); } public void addMessage (final String message) { EventQueue.invokeLater(new Runnable() { public void run () { DefaultListModel model = (DefaultListModel)messageList.getModel(); model.addElement(message); messageList.ensureIndexIsVisible(model.size() - 1); } }); } } public JPanel getChatPanel(){ return chatPanel; } }

    Read the article

  • JDO in Google App Engine: order of keys in unowned one-to-many relationship

    - by Kel
    I'm implementing web application with JDO in Google App Engine. According to documentation, in owned one-to-many relationships, order of elements in "owner" object collection is determined either by automatically created index field, or by information given in explicit ordering clause. For example: @PersistenceCapable public class Person { // ... @Order(extensions = @Extension(vendorName="datanucleus", key="list-ordering", value="country asc, city asc")) private List<ContactInfo> contacts = new List<ContactInfo>(); In unowned relationships, "owner" object contains collection of keys of "nested" objects, for example: @PersistenceCapable public class Author { // ... @Persistent private List<Key> books; Is order of keys preserved, if I use List<Key> collection in "owner" object for storing keys of "nested" elements? I could not find answer neither in JDO relationships article, nor in Data Classes article :(

    Read the article

< Previous Page | 806 807 808 809 810 811 812 813 814 815 816 817  | Next Page >