Search Results

Search found 34660 results on 1387 pages for 'effective java'.

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 330/1387 | < Previous Page | 326 327 328 329 330 331 332 333 334 335 336 337  | Next Page >

  • Whats the best way to parse a file in Java

    - by chitresh
    Hi All, I have a text file with Tag - Value format data. I want to parse this file to form a Trie. What will be the best approach? Sample of File: (String inside "" is a tag and '#' is used to comment the line.) #Hi, this is a sample file. "abcd" = 12; "abcde" = 16; "http" = 32; "sip" = 21;

    Read the article

  • Help with enums in Java

    - by devoured elysium
    Is it possible to have an enum change its value (from inside itself)? Maybe it's easier to understand what I mean with code: enum Rate { VeryBad(1), Bad(2), Average(3), Good(4), Excellent(5); private int rate; private Rate(int rate) { this.rate = rate; } public void increateRating() { //is it possible to make the enum variable increase? //this is, if right now this enum has as value Average, after calling this //method to have it change to Good? } } This is want I wanna achieve: Rate rate = Rate.Average; System.out.println(rate); //prints Average; rate.increaseRating(); System.out.println(rate); //prints Good Thanks

    Read the article

  • [Java] Listening for TCP and UDP requests on the same port

    - by user339328
    I am writing a Client/Server set of programs Depending on the operation requested by the client, I use make TCP or UDP request. Implementing the client side is straight-forward, since I can easily open connection with any protocol and send the request to the server-side. On the servers-side, on the other hand, I would like to listen both for UDP and TCP connections on the same port. Moreover, I like the the server to open new thread for each connection request. I have adopted the approach explained in: link text I have extended this code sample by creating new threads for each TCP/UDP request. This works correctly if I use TCP only, but it fails when I attempt to make UDP bindings. Please give me any suggestion how can I correct this. tnx

    Read the article

  • Java: Using multiple Threads to paint simultaniously on a JPanel

    - by user347217
    I have a JPanel on which I wish to have several threads painting "animations" on. An "animation" consists of a JLabel with an ImageIcon on it, which is being moved from one area of the screen to another area. Now, problem is - I want several such animations to be portrayed on screen by those threads mentioned. Problem is - the JPanel's "paint()" method can only be trigged by one thread at a time - causing the animations to execute serially, instead of in a parallel way. Any idea how to have several such animations on screen at the same time?

    Read the article

  • Having access to a private variable from other classes in Java

    - by Crystal
    If I want to create a form that adds people to a List, how do I have access to that List from another class? Where would I define that List so other classes can access the members, the size, etc? For example, if I have Class Foo that has the GUI for my form, along with buttons to add and remove people to the List, it would make sense to me to declare the List as a private instance variable of Class Foo. But then if I have another class, Class Bar, how does it get the values that are currently in that List to update some other graphical components? Or is that the wrong place to declare the List in general? Thanks.

    Read the article

  • ArrayList to Array of Strings in java

    - by rajivpradeep
    ArrayList<String> newArray = new ArrayList<String>(); newArray = urlList.getUrl(); for( int i = 0 ; i < newArray.size();i++) { System.out.println(newArray.get(i)); } newArray.toArray(mStrings );// is this correct mStrings = newArray.toArray();// or this to convert ArrayList ot String array here for( int i = 0 ; i < mStrings.length;i++) { System.out.println(mStrings[i]); }

    Read the article

  • Java Applet Buffering images

    - by Dan
    OK so here's my code: http://www.so.pastebin.com/Qca4ERmy I am trying to use buffers so the applet won't flicker upon redraw() but it seems I am having trouble. The applet still flickers.... Help? Thank you.

    Read the article

  • Pointer-like behavior in Java

    - by Shmoo
    I got the following: class A{ int foo; } class B extends A{ public void bar(); } I got a instance of A and want to convert it to an instance of B without losing the reference to the variable foo. For example: A a = new A(); a.foo = 2; B b = a; <-- what I want to do. //use b b.foo = 3; //a.foo should now be 3 Thanks for any help!

    Read the article

  • Drag and Drop and identify locations with java

    - by out_sider
    I'm trying to do something quite simple, but I'm having a hard time finding good examples on the net to what I want specifically. I'd like to somehing very similer to what it's here: Dao It's a simple game called DAO and I just need to have a background image with 16 squares (4x4) and drag and drop the images (pieces) on each square to the others. I'm developing the interface using swing and I simply want to know a good place to find tutorials for such implementations or a simple suggestion on how to do it. Thanks in advance

    Read the article

  • What is the explanation of this java code ?

    - by M.H
    I have the following code : public class Main { public void method(Object o) { System.out.println("Object Version"); } public void method(String s) { System.out.println("String Version"); } public static void main(String args[]) { Main question = new Main(); question.method(null);//1 } } why is the result is "String Version" ? and why there is a compiler error if the first method takes a StringBuffer object ?

    Read the article

  • Why does java.util.concurrent.ArrayBlockingQueue use 'while' loops instead of 'if' around calls to

    - by theFunkyEngineer
    I have been playing with my own version of this, using 'if', and all seems to be working fine. Of course this will break down horribly if signalAll() is used instead of signal(), but if only one thread at a time is notified, how can this go wrong? Their code here - check out the put() and take() methods; a simpler and more-to-the-point implementation can be seen at the top of the JavaDoc for Condition. Relevant portion of my implementation below. public Object get() { lock.lock(); try { if( items.size() < 1 ) hasItems.await(); Object poppedValue = items.getLast(); items.removeLast(); hasSpace.signal(); return poppedValue; } catch (InterruptedException e) { e.printStackTrace(); return null; } finally { lock.unlock(); } } public void put(Object item) { lock.lock(); try { if( items.size() >= capacity ) hasSpace.await(); items.addFirst(item); hasItems.signal(); return; } catch (InterruptedException e) { e.printStackTrace(); } finally { lock.unlock(); } } P.S. I know that generally, particularly in lib classes like this, one should let the exceptions percolate up.

    Read the article

  • Trying to get the associated value from an Enum at runtime in Java

    - by devoured elysium
    I want to accomplish something like the following (my interest is in the toInt() method). Is there any native way to accomplish this? If not, how can I get the integer associated with an enum value (like in C#) ? enum Rate { VeryBad(1), Bad(2), Average(3), Good(4), Excellent(5); private int rate; private Rate(int rate) { this.rate = rate; } public int toInt() { return rate; } } Thanks

    Read the article

  • How to transform huge xml files in java?

    - by fx42
    As the title says it, I have a huge xml file (GBs) <root> <keep> <stuff> ... </stuff> <morestuff> ... </morestuff> </keep> <discard> <stuff> ... </stuff> <morestuff> ... </morestuff> </discard> </root> and I'd like to transform it into a much smaller one which retains only a few of the elements. My parser should do the following: 1. Parse through the file until a relevant element starts. 2. Copy the whole relevant element (with children) to the output file. go to 1. step 1 is easy with SAX and impossible for DOM-parsers. step 2 is annoying with SAX, but easy with the DOM-Parser or XSLT. so what? - is there a neat way to combine SAX and DOM-Parser to do the task?

    Read the article

  • Java Multi threading - Avoid duplicate request processing

    - by seawaves
    I have following multi threaded environment scenario - Requests are coming to a method and I want to avoid the duplicate processing of concurrent requests coming. As multiple similar requests might be waiting for being processed in blocked state. I used hashtable to keep track of processed request, but it will create memory leaks, so how should keep track of processed request and avoid the same requests to be processed which may be in blocking state.

    Read the article

  • Problem decrementing in Java with '-='

    - by hanesjw
    I'm making a scrolling game on Android and am having a hard time figuring out why the code below does not decrement past 0. Objects start at the end of the screen (so the x position is equal to the width of the screen) the objects move accross the screen by decrementing their x positions. I want them to scroll off of the screen, but when the x position hits 0, the objects just stay at 0, they do not move into the negatives. Here is my code to move objects on the screen private void incrementPositions(long delta) { float incrementor = (delta / 1000F) * Globals.MAP_SECTION_SPEED; for(Map.Entry<Integer, HashMap<Integer, MapSection>> column : scrollingMap.entrySet()) { for(Map.Entry<Integer, MapSection> row : column.getValue().entrySet()) { MapSection section = row.getValue(); section.x -= incrementor; } } } It works ok if I change section.x -= incrementor; to section.x = section.x - (int)incrementor; but if i do that the scrolling doesn't appear as smooth.

    Read the article

  • Java inheritance question

    - by user247866
    So I have 3 classes. Abstract class A Class B extends class A independent Class C In class D that contains the main method, I create a list of instances of class B List<B> b = method-call();` // the method returns a list of instances of class B Now in class C I have one method that is common to both A and B, and hence I don't want to duplicate it. I want to have one method that takes as input an instance of class A, as follows: public void some-method(LIst<A> a) However, when I do: C c = new C(). c. some-method(b) I get an error that some-method is not applicable for the argument List, instead it's expecting to get List. Is there a good way to fix this problem? Many thanks!

    Read the article

  • Cannot create an array of LinkedLists in Java...?

    - by kchau
    I'm working on a sparse matrix class that needs to use an array of LinkedLists to store the values of a matrix. Each element of the array (i.e. each LinkedList) represents a row of the matrix. And, each element in the LinkedLists represents a column and the stored value. In my class, I have a declaration of the array as: private LinkedList<IntegerNode>[] myMatrix; And, in my constructor for the SparseMatrix, I try to define: myMatrix = new LinkedList<IntegerNode>[numRows]; The error I end up getting is "Cannot create a generic array of LinkedList<IntegerNode>." So, I have two issues with this, 1) What am I doing wrong, and 2) Why is the type acceptable in the declaration for the array if it can't be created? Edit: IntegerNode is a class that I have created. And, all of my class files are packaged together.

    Read the article

  • Java threading problem

    - by Krt_Malta
    Hi! I'm using multiple threads in my application. Basically I have a combo box and upon selecting Inbox, p1 resumes and p2 is suspended and upon selecting Send, p2 starts and p1 stops. Below is the code (I'm sure it's not perfect) public void modifyText(ModifyEvent e) { if (combo.getText().equals("Inbox")) { synchronized(p2) { p2.cont = false; } table.removeAll(); synchronized(p1) { p1.cont = true; p1.notify(); } } else if (combo.getText().equals("Sent")) { synchronized(p2) { p1.cont = false; } table.removeAll(); synchronized(p1) { p2.cont = true; p2.notify(); } } } }); and for P1 and P2 I have this inside their while loops: synchronized (this) { while (cont == false) try { wait(); } catch (Exception e) { } } ... As it is it's now working (I'm a beginner to threads). On pressing Sent in the combo box, I get an IllegalStateMonitorException. Could anyone help me solve the problem plz? Thanks and regards, Krt_Malta

    Read the article

  • Java loop and increment problem

    - by user552961
    Can any one tell me what is the problem in my program? String a[],b[]; int c[] = new int[b.length]; for (int j = 0; j < a.length; j++) { for (int k = 0; k < b.length; k++) { if (b[k].equals(a[j])) { c[k]++; } else { c[k] = 0; } } } I have thousands of words stored in a HashMap. Now I want to check in every file that how many time one word occurred from allWords. Can you point out mistake in my program or give me your idea that how I can do it?

    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 | 326 327 328 329 330 331 332 333 334 335 336 337  | Next Page >