Search Results

Search found 32961 results on 1319 pages for 'java (javase6'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 287/1319 | < Previous Page | 283 284 285 286 287 288 289 290 291 292 293 294  | Next Page >

  • Memory allocation in java

    - by Girish
    class Someobject { int i=10; } public class OtherObject { public static void main(String args[]) { Someobject obj=new Someobject(); System.out.println(obj.i); } } Please tell me in which section of the memory: This entire code will load. Where will someobject will be stored. Where will obj will be stored Where will i be stored. Thanks every one in advance.

    Read the article

  • Dijkstra's Algorithm explanation java

    - by alchemey89
    Hi, I have found an implementation for dijkstras algorithm on the internet and was wondering if someone could help me understand how the code works. Many thanks private int nr_points=0; private int[][]Cost; private int []mask; private void dijkstraTSP() { if(nr_points==0)return; //algorithm=new String("Dijkstra"); nod1=new Vector(); nod2=new Vector(); weight=new Vector(); mask=new int[nr_points]; //initialise mask with zeros (mask[x]=1 means the vertex is marked as used) for(int i=0;i<nr_points;i++)mask[i]=0; //Dijkstra: int []dd=new int[nr_points]; int []pre=new int[nr_points]; int []path=new int[nr_points+1]; int init_vert=0,pos_in_path=0,new_vert=0; //initialise the vectors for(int i=0;i<nr_points;i++) { dd[i]=Cost[init_vert][i]; pre[i]=init_vert; path[i]=-1; } pre[init_vert]=0; path[0]=init_vert; pos_in_path++; mask[init_vert]=1; for(int k=0;k<nr_points-1;k++) { //find min. cost in dd for(int j=0;j<nr_points;j++) if(dd[j]!=0 && mask[j]==0){new_vert=j; break;} for(int j=0;j<nr_points;j++) if(dd[j]<dd[new_vert] && mask[j]==0 && dd[j]!=0)new_vert=j; mask[new_vert]=1; path[pos_in_path]=new_vert; pos_in_path++; for(int j=0;j<nr_points;j++) { if(mask[j]==0) { if(dd[j]>dd[new_vert]+Cost[new_vert][j]) { dd[j]=dd[new_vert]+Cost[new_vert][j]; } } } } //Close the cycle path[nr_points]=init_vert; //Save the solution in 3 vectors (for graphical purposes) for(int i=0;i<nr_points;i++) { nod1.addElement(path[i]); nod2.addElement(path[i+1]); weight.addElement(Cost[path[i]][path[i+1]]); } }

    Read the article

  • Java Binary Tree. Priting InOrder traversal

    - by user69514
    I am having some problems printing an inOrder traversal of my binary tree. Even after inserting many items into the tree it's only printing 3 items. public class BinaryTree { private TreeNode root; private int size; public BinaryTree(){ this.size = 0; } public boolean insert(TreeNode node){ if( root == null) root = node; else{ TreeNode parent = null; TreeNode current = root; while( current != null){ if( node.getData().getValue().compareTo(current.getData().getValue()) <0){ parent = current; current = current.getLeft(); } else if( node.getData().getValue().compareTo(current.getData().getValue()) >0){ parent = current; current = current.getRight(); } else return false; if(node.getData().getValue().compareTo(parent.getData().getValue()) < 0) parent.setLeft(node); else parent.setRight(node); } } size++; return true; } /** * */ public void inOrder(){ inOrder(root); } private void inOrder(TreeNode root){ if( root.getLeft() !=null) this.inOrder(root.getLeft()); System.out.println(root.getData().getValue()); if( root.getRight() != null) this.inOrder(root.getRight()); } }

    Read the article

  • Using interfaces in java..Newb question

    - by Rahul
    Suppose there in an interface Displaceable and a class Circle which implements Displaceable. Displaceable has a method named move() which of course is implemented in Circle. What would happen in the following scenario? Circle a = new Circle(..); Displaceable b = a; b.move() Would the object refer to the Circle's move method?

    Read the article

  • Override Java System.currentTimeMillis

    - by Mike Clark
    Is there a way, either in code or with JVM arguments, to override the current time, as presented via System.currentTimeMillis, other than manually changing the system clock on the host machine? A little background: We have a system that runs a number of accounting jobs that revolve much of their logic around the current date (ie 1st of the month, 1st of the year, etc) Unfortunately, a lot of the legacy code calls functions such as new Date() or Calendar.getInstance(), both of which eventually call down to System.currentTimeMillis. For testing purposes, right now, we are stuck with manually updating the system clock to manipulate what time and date the code thinks that the test is being run. So my question is: Is there a way to override what is returned by System.currentTimeMillis? For example, to tell the JVM to automatically add or subtract some offset before returning from that method? Thanks in advance!

    Read the article

  • Should I catch exceptions thrown when closing java.sql.Connection

    - by jb
    Connection.close() may throw SqlException, but I have always assumed that it is safe to ignore any such exceptions (and I have never seen code that does not ignore them). Normally I would write: try{ connection.close(); }catch(Exception e) {} Or try{ connection.close(); }catch(Exception e) { logger.log(e.getMessage(), e); } The question is: Is it bad practice (and has anyone had problems when ignoring such exeptions). When Connection.close() does throw any exception. If it is bad how should I handle the exception. Comment: I know that discarding exceptions is evil, but I'm reffering only to exceptions thrown when closing a connection (and as I've seen this is fairly common in this case). Does anyone know when Connection.close() may throw anything?

    Read the article

  • Cast element in Java For Each statement

    - by Carl Summers
    Is it possible (or even advisable) to cast the element retrieved from a for each statement in the statement itself? I do know that each element in list will be of type . I.E.: List<BaseType> list = DAO.getList(); for(<SubType> element : list){ // Cannot convert from element type <BaseType> to <SubType> ... } rather than: List <BaseType> list = DAO.getList(); for(<BaseType> el : list){ <SubType> element = (<SubType>)el; ... }

    Read the article

  • Duplicates in a sorted java array

    - by Max Frazier
    I have to write a method that takes an array of ints that is already sorted in numerical order then remove all the duplicate numbers and return an array of just the numbers that have no duplicates. That array must then be printed out so I can't have any null pointer exceptions. The method has to be in O(n) time, can't use vectors or hashes. This is what I have so far but it only has the first couple numbers in order without duplicates and then just puts the duplicates in the back of the array. I can't create a temporary array because it gives me null pointer exceptions. public static int[] noDups(int[] myArray) { int j = 0; for (int i = 1; i < myArray.length; i++) { if (myArray[i] != myArray[j]) { j++; myArray[j] = myArray[i]; } } return myArray; }

    Read the article

  • Java - Circular Garbage Collection

    - by aloh
    A <- B <- C <- D <- A... // A is firstNode, D is lastNode if ( length == 1 ) { firstNode = null; lastNode = null; firstNode.next = null; firstNode.prev = null; } else { Node secondNode = firstNode.next; Node secondToLast = lastNode.prev; firstNode.next = null; firstNode.prev = null; lastNode.next = null; lastNode.prev = null; secondNode.prev = null; secondToLast.next = null; firstNode = null; lastNode = null; } That should send everything in between as candidates for garbage collection, I hope?

    Read the article

  • JAVA: Build XML document using XPath expressions

    - by snoe
    I know this isn't really what XPath is for but if I have a HashMap of XPath expressions to values how would I go about building an XML document. I've found dom-4j's DocumentHelper.makeElement(branch, xpath) except it is incapable of creating attributes or indexing. Surely a library exists that can do this? Map xMap = new HashMap(); xMap.put("root/entity/@att", "fooattrib"); xMap.put("root/array[0]/ele/@att", "barattrib"); xMap.put("root/array[0]/ele", "barelement"); xMap.put("root/array[1]/ele", "zoobelement"); would result in: <root> <entity att="fooattrib"/> <array><ele att="barattrib">barelement</ele></array> <array><ele>zoobelement</ele></array> </root>

    Read the article

  • Mix of Arabic and English causes problems in JTextArea (Java)

    - by Dan
    I have a JTextArea which displays HTML of an Arabic web page. So it's essentially a mix of English and Arabic. In the JTextArea, with columns set to 30, certain text just disappears instead of wrapping properly. The weird thing is that if I copy the invisible text and paste it into Notepad, then I can see it in Notepad. If I change the number of columns to 40, everything displays fine. Any ideas?

    Read the article

  • Timeout with GAE Java

    - by user242153
    Hi, I am having some issues with an app I have deployed on GAE. Specifically, I am intermittently running into the DeadlineExceededException where the server is not responding within the 30 seconds required. What is odd is that the code is not overly complex, it should run in milliseconds. My guess is that the delay is in dealing with the persistence manager and accessing the datastore. 2 questions: 1) What is the best way to track where all of the CPU time on the server is being used up? Log files do not seem helpful and to make things more complicated the code runs very fast when I am running it locally 2) Any tips / best practices in dealing with the 30 second exception? What are the biggest drivers of this? Datastore? HTTP requests / responses? Thanks

    Read the article

  • java - unwanted object overwriting

    - by gosling
    Hello everyone! I'm trying to make a program that solves the logic wheels puzzle. I construct the root node and I try to produce the different child-nodes that are produced by making different moves of the wheels. The problem is that while I try to produce the children, the root node is overwrited,and everything is messed-up and I really don't know why. Here you can find the puzzle logic wheels. I represent the wheels as 3x3 arrays. Here is the code that implements the moves: public Node turn_right(Node aNode, int which_wheel) { Node newNode = new Node(aNode.getYellow_wheel(),aNode.getBlue_wheel(),aNode.getGreen_wheel()); int[][] yellow = new int[3][3]; int[][] blue = new int[3][3]; int[][] green = new int[3][3]; if(which_wheel==0) //turn yellow wheel of this node to right { yellow[1][0] = newNode.getYellow_wheel()[0][0]; yellow[2][0] = newNode.getYellow_wheel()[1][0]; yellow[2][1] = newNode.getYellow_wheel()[2][0]; yellow[2][2] = newNode.getYellow_wheel()[2][1]; yellow[1][2] = newNode.getYellow_wheel()[2][2]; yellow[0][2] = newNode.getYellow_wheel()[1][2]; yellow[0][1] = newNode.getYellow_wheel()[0][2]; yellow[0][0] = newNode.getYellow_wheel()[0][1]; blue = newNode.getBlue_wheel(); blue[1][0] = newNode.getYellow_wheel()[1][2]; blue[2][0] = newNode.getYellow_wheel()[2][2]; green = newNode.getGreen_wheel(); } else if(which_wheel == 1)// turn blue wheel of this node to right { blue[1][0] = newNode.getBlue_wheel()[0][0]; blue[2][0] = newNode.getBlue_wheel()[1][0]; blue[2][1] = newNode.getBlue_wheel()[2][0]; blue[2][2] = newNode.getBlue_wheel()[2][1]; blue[1][2] = newNode.getBlue_wheel()[2][2]; blue[0][2] = newNode.getBlue_wheel()[1][2]; blue[0][1] = newNode.getBlue_wheel()[0][2]; blue[0][0] = newNode.getBlue_wheel()[0][1]; yellow = newNode.getYellow_wheel(); yellow[0][2] = newNode.getBlue_wheel()[0][0]; yellow[1][2] = newNode.getBlue_wheel()[1][0]; green = newNode.getGreen_wheel(); green[1][0] = newNode.getBlue_wheel()[1][2]; green[2][0] = newNode.getBlue_wheel()[2][2]; } else if (which_wheel == 2)//turn green wheel of this node to right { green[0][0] = newNode.getGreen_wheel()[0][1]; green[0][1] = newNode.getGreen_wheel()[0][2]; green[0][2] = newNode.getGreen_wheel()[1][2]; green[1][2] = newNode.getGreen_wheel()[2][2]; green[2][2] = newNode.getGreen_wheel()[2][1]; green[2][1] = newNode.getGreen_wheel()[2][0]; green[2][0] = newNode.getGreen_wheel()[1][0]; green[1][0] = newNode.getGreen_wheel()[0][0]; yellow = newNode.getYellow_wheel(); blue = newNode.getBlue_wheel(); blue[0][2] = newNode.getGreen_wheel()[0][0]; blue[1][2] = newNode.getGreen_wheel()[1][0]; } newNode= new Node(yellow,blue,green); return newNode; } There is another function, like this one that does the oposite:it turns the wheels to left. My problem is that I do not want object's aNode tables to be overwritten. Thank you very much.

    Read the article

  • [Java] Implement a RSA algorithm

    - by Robin Monjo
    Hello everyone. I want to implement a RSA algorithm to encrypt an image (byte[]). To generate my two keys I used this piece of code : KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA"); keygen.initialize(512); keyPair = keygen.generateKeyPair(); Once public and private key are generated, I would like to show them to the user so he can distribute the public key and use the private key to decode. How can I get back those key ? Using keygen.getPrivateKey() and keygen.getPublicKey() give me all the information of the RSA algorithm, not only the keys I need. Thanks

    Read the article

  • export a JOGL applet and embedd into a html page

    - by nkint
    hi guys it is some time that i'm testing opengl with java and JOGL. now i have good result and i wanto to pubblish it on web. but i have some problem. i'm in eclipse, and i'm testing an Applet with JOGL. first of all i have this run time error (but the program works correctly): java.lang.IllegalArgumentException: adding a window to a container at java.awt.Container.checkNotAWindow(Container.java:431) at java.awt.Container.addImpl(Container.java:1039) at java.awt.Container.add(Container.java:365) at AppletHelloWorld.init(AppletHelloWorld.java:30) at sun.applet.AppletPanel.run(AppletPanel.java:424) at java.lang.Thread.run(Thread.java:619) then i found this incredibly clear page and i do what is said, i open html with the browser, the libs are downloaded but it stops at "Starting applet AppletHelloWorld" that is the name i gave to my applet. mayebe i miss something like main function or exporting well the jar? this is my main code: public class AppletHelloWorld extends Applet { public static void main(String[] args) { JFrame fr=new JFrame(); fr.setBounds(0,0,1015,600); fr.add(new AppletHelloWorld()); fr.setVisible(true); } public void init() { setLayout(null); MyJOGLProject canvas = new MyJOGLProject(); //MyJOGLProject extends JFrame canvas.run(); Container c = new Container(); c.add(canvas); add(c); } //....

    Read the article

  • asking the container to notify your application whenever a session is about to timeout in Java

    - by user136101
    Which method(s) can be used to ask the container to notify your application whenever a session is about to timeout?(choose all that apply) A. HttpSessionListener.sessionDestroyed -- correct B. HttpSessionBindingListener.valueBound C. HttpSessionBindingListener.valueUnbound -- correct this is kind of round-about but if you have an attribute class this is a way to be informed of a timeout D. HttpSessionBindingEvent.sessionDestroyed -- no such method E. HttpSessionAttributeListener.attributeRemoved -- removing an attribute isn’t tightly associated with a session timeout F. HttpSessionActivationListener.sessionWillPassivate -- session passivation is different than timeout I agree with option A. 1) But C is doubtful How can value unbound be tightly coupled with session timeout.It is just the callback method when an attribute gets removed. 2) and if C is correct, E should also be correct. HttpSessionAttributeListener is just a class that wants to know when any type of attribute has been added, removed, or replaced in a session. It is implemented by any class. HttpSessionBindingListener exists so that the attribute itself can find out when it has been added to or removed from a session and the attribute class must implement this interface to achieve it. Any ideas…

    Read the article

  • Selenium Webdriver Java - looking for alternatives for Actions and Robot when performing drag-and-drop

    - by Ja-ke Alconcel
    I first tried Actions class and the drag-and-drop does work on different elements, however it was unable to locate the a specific draggable element on it's exact screen/webpage position. Here's the code I've used: Point loc = driver.findElement(By.id("thiselement")).getLocation(); System.out.println(loc); WebElement drag = driver.findElement(By.id("thiselement")); Actions test = new Actions(driver); test.dragAndDropBy(drag, 0, 60).build().perform(); I checked the element with it's pixel location and it prints (837, -52), which was somewhere on top of the webpage and was pixels away from the actual element. Then I tried using the Robot class and works perfectly fine on my script, but can only provide constant successful runs on a single test machine, running it with a different machine with different screen resolution and screen size will render the script to fail due to the dependency of Robot on the pixel location of the element. The sample code of the Robot script I'm using: Robot dragAndDrop = new Robot(); dragAndDrop.mouseMove(945, 166); //actual pixel location of the draggable element dragAndDrop.mousePress(InputEvent.BUTTON1_MASK); sleep(3000); dragAndDrop.mouseMove(945, 226); dragAndDrop.mouseRelease(InputEvent.BUTTON1_MASK); sleep(3000); Is there any alternative for Actions and Robot to automate drag-and-drop? Or maybe a help on working the script to work on Actions as I really can't use Robot. Thanks in advance.

    Read the article

  • Java Enum List from Class

    - by DD
    How do I go from a Class object to a list of enums generically? i.e. public static <T extends Enum> List<T> getList(Class<T> clazz) I cant find a way to get to the values() method

    Read the article

  • Java generics: Illegal forward reference

    - by Arian
    Given a generic interface interface Foo<A, B> { } I want to write an implementation that requires A to be a subclass of B. So I want to do class Bar<A, B super A> implements Foo<A, B> { } // --> Syntax error or class Bar<A extends B, B> implements Foo<A, B> { } // --> illegal forward reference But the only solution that seems to work is this: class Bar<B, A extends B> implements Foo<A, B> { } which is kind of ugly, because it reverses the order of the generic parameters. Are there any solutions or workarounds to this problem?

    Read the article

  • Class unloading in java

    - by java_geek
    When a classloader is garbage collected, are the classes loaded by it unloaded? When the JVM is running is verbose mode, all the loaded classes are o/p. Similarly will the JVM log when it unloads a class? I wrote a custom class loader to test this, but could not see any verbose log for unloading of the classes. CustomClassLoader loader = new CustomClassLoader(new URL[]{}, CustomClassLoader.class.getClassLoader()); loader.addURL("D:\workspace\ClassLoaderTest\implementation.jar"); Class c = null; try { c = Class.forName("Horse",false,loader); if (c != null) { try { Animal animal = (Animal)c.newInstance(); animal.eat(); } catch(Exception ex) { ex.printStackTrace(); } } } catch(Exception e) { e.printStackTrace(); } loader = null; byte[] b = new byte[58*1024*1024]; System.gc(); ClassLoadingMXBean clBean = ManagementFactory.getClassLoadingMXBean(); System.out.println("Number of classes currently loaded " + clBean.getLoadedClassCount()); System.out.println("Number of classes loaded totally " + clBean.getTotalLoadedClassCount()); System.out.println("Number of classes unloaded " + clBean.getUnloadedClassCount()); Even the ClassLoadingMXBean gives number of unloaded classes as 0. How can i know that a class is unloaded when the class loader is GCed?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 283 284 285 286 287 288 289 290 291 292 293 294  | Next Page >