Search Results

Search found 35513 results on 1421 pages for 'java interfaces'.

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 324/1421 | < Previous Page | 320 321 322 323 324 325 326 327 328 329 330 331  | Next Page >

  • Java Hibernate Lazy=false

    - by Noor
    When setting Lazy=false, then hibernate will automatically loads the objects into the required sets e.g. <set name="Options" table="ATTRIBUTEOPTION" inverse="false" cascade="all" lazy="false"> <key> <column name="ATTRIBUTEID" /> </key> <one-to-many class="com.BiddingSystem.Models.AttributeOption" /> </set> but if in my xml mapping, I place lazy=true and in some place in my application i decide that i want to load all attribute options, should i do it manually, or is there a technique which lets tells hibernate that now i want to set lazy=false??

    Read the article

  • Java splitting string by custom regex match

    - by slikz
    I am completely new to regular expressions so I'm looking for a bit of help here. I am compiling under JDK 1.5 Take this line as an example that I read from standard input: ab:Some string po:bubblegum What I would like to do is split by the two characters and colon. That is, once the line is split and put into a string array, these should be the terms: ab:Some string po:bubblegum I have this regex right now: String[] split = input.split("[..:]"); This splits at the semicolon; what I would like is for it to match two characters and a semicolon, but split at the space before that starts. Is this even possible? Here is the output from the string array: ab Some String po bubblegum I've read about Pattern.compile() as well. Is this something I should be considering?

    Read the article

  • Java Null Pointer Exception :-(

    - by John-Michael Reed
    I've got a Null Pointer Exception in my main that just won't go away and I'm totally out of ideas. The error is on the line "Board[x][y].color = 2;" in which Board is a public, static array of piece objects that contain instance variables like the one "color" that is being set to 2 in the above statement. Pieces is not static - that is there are many different copies of pieces, each with its own data, but only one board. The array has been initialized and defined as both public Piece[][] Board = new Piece[8][8] and public static Piece[][] Board = new Piece[8][8], but no matter how I mess around with it (getting rid of static, putting the variable in another object, etc.), I can't seem to get the error to go away. Help?

    Read the article

  • What is a good "Error Checking" Pattern (Java)?

    - by Jack
    I'll explain what I mean by input error checking. Say you have a function doSomething(x). If the function completes successfully doSomething does something and returns nothing. However, if there are errors I'd like to be notified. That is what I mean by error checking. I'm looking for, in general, the best way to check for errors. I've thought of the following solutions, each with a potential problem. Flag error checking. If doSomething(x) completes successfully return null. Otherwise, it returns a boolean or an error string. Problem: Side effects. Throwing an exception. Throw an exception if doSomething(x) encounters an error. Problem: If you are performing error checking for parameters only, throwing an IllegalArgumentExceptionseems inappropriate. Validating input prior to function call. If the error checking is only meant for the parameters of the function, then you can call a validator function before calling the doSomething(x) function. Problem: What if a client of the class forgets to call the validator function before calling doSomething(x)? I often encounter this problem and any help or a point in the right direction would be much appreciated.

    Read the article

  • Using enums in Java across multiple classes

    - by Richard Mar.
    I have the following class: public class Card { public enum Suit { SPACES, HEARTS, DIAMONDS, CLUBS }; public Card(Suit nsuit, int nrank) { suit = nsuit; rank = nrank; } private Suit suit; private int rank; } I want to instantiate it in another class, but that class doesn't understand the Suit enum. Where should I put the enum to make it publicly visible?

    Read the article

  • force warning in java

    - by Dustin Getz
    I'd like a mechanism to throw a compile-time warning manually. I'm using it to flag unfinished code so I can't possibly forget about it later. @Deprecated is close but warns at caller site, not at creation site. I'm using eclipse. Something like #Warning in C#.

    Read the article

  • Java giving incorrect year values

    - by whistler
    Something very, very strange is occurring in my program, and I'm wondering if anyone out there has seen this occur before. And, if so, how to fix it. Basically, I am parsing an csv file...no problem there. One column contains a date and I am taking it in as a String and changing to a Date object. Again, no problem there. The code is as follows: SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yy hh:mm"); Date initialDate = new Date(); try { initialDate = dateFormat.parse(rows.get(0)[8]); System.out.println(initialDate); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } Of course, I'm parsing other columns as well (and those are working fine). So, when I run my program for a small csv file (2.8 MB), the dates come out (i.e. are parsed) perfectly. However, when I run the program for a large csv file (25 MB), the dates are a hot mess. For example, take a look at the year values I am getting (the following is just a tiny portion of the println output from the code above): 1000264 at Sun Nov 05 15:30:00 EST 2186 1000320 at Sat Mar 04 17:30:00 EST 2169 1000347 at Sat Apr 01 09:45:00 EDT 2169 1000413 at Tue Jul 09 13:00:00 EDT 2182 1000638 at Fri Dec 11 13:45:00 EST 2167 1000667 at Wed Dec 10 10:00:00 EST 2188 1000690 at Mon Jan 02 13:00:00 EST 2169 1000843 at Thu Feb 11 13:30:00 EST 2196 In actuality, the years are in the realm of 1990-2006 or so. Again, this does not happen with the small csv file. Does anyone know what's going on here and how I can fix it? I need to process the large csv file (the small one was just for testing purposes). By request, here are the actual dates in the csv file and after that the value given by the code above: 5/20/03 15:30 5/20/03 15:30 8/30/04 9:00 8/30/04 9:00 12/20/04 10:30 12/20/04 10:30 Sun Nov 05 15:30:00 EST 2186 Sun Nov 05 15:30:00 EST 2186 Sun Nov 05 15:30:00 EST 2186 Thu Dec 08 09:00:00 EST 2196 Tue Dec 12 10:30:00 EST 2186 Tue Dec 12 10:30:00 EST 2186

    Read the article

  • java - Depth First Search - Perform DFS on a tree

    - by DJDonaL3000
    Im trying to perform DFS on a Minimum Spanning Tree which contains 26 nodes. Nodes are named 'A' to 'Z' and the tree is undirected. I have an empty function called DFS here that I am trying to write, which (i presume) takes in the tree (a 2D array) a startNode (randomly selected node 'M') and the endNode (randomly selected node 'Z'). The weights of connected nodes are identified in the 2D array parameter, but how do I actually get started visiting nodes? All that is required is to print each nodeName in the order of the DFS traversal. Do I need to create a Node_class for each node in the 2d array??

    Read the article

  • JAVA: How do I accept input during a certain period of time only

    - by sebrock
    Im trying to do a simple game where I continually need input from players. This needs to happen during a certain time period only. Everything that is sent after that will be discarded. After the time period a new game starts. So: Start game Wait for input from all players during 10 seconds 10 secs no more input Calculate the winner and do some stuff Goto 1. I was thinking using a timer and timertask to keep track of time and maybe use a boolean variable that changes from "open" to "closed" after 10 seconds? Please give me some advise on this.

    Read the article

  • java overloaded method

    - by Sean Nguyen
    Hi, I have an abstract template method: class abstract MyTemplate { public void something(Object obj) { doSomething(obj) } protected void doSomething(Object obj); } class MyImpl extends MyTemplate { protected void doSomething(Object obj) { System.out.println("i am dealing with generic object"); } protected void doSomething(String str) { System.out.println("I am dealing with string"); } } public static void main(String[] args) { MyImpl impl = new MyImpl(); impl.something("abc"); // --> this return "i am dealing with generic object" } How can I print "I am dealing with string" w/o using instanceof in doSomething(Object obj)? Thanks,

    Read the article

  • Revalidate and repaint - Java Swing

    - by bosra
    I have a JPanel that I am adding JLabel's to. I then want to remove all the JLabels and add some new ones. So I do the following: panel.removeAll();panel.repaint(); panel.add(new JLabel("Add something new"); panel.revalidate(); This works fine. My problem arises when I start a new thread after this like: panel.removeAll();panel.repaint(); (1)panel.add(new JLabel("Add something new"); panel.revalidate(); //new thread to start - this thread creates new JLabels that should appear under (1) firstProducer.start(); try { firstProducer.join(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } Then the output from the original JLabels is still visible. I have read that the revalidate process is a long running task and hence the firstProducer thread is getting started while the revalidation is going on and a conflict is arising. What is the best way to deal with this?

    Read the article

  • Regex to match a Java method signature

    - by nitesh
    I am having this particular requirement where a method has to be identified by different regular expressions for different components. For example, there need to be a regex for return parameter, one for method name, one for argument type and one for argument name. I was able to come up with an expression till this step as follows - ([^,]+) ([^,]+)\((([^,]+) ([^,]+))\) It works well for a method signature like - ReturnType foo(Arg parameter) The regular expression identifies ReturnType, foo, Arg and parameter separately. Now the problem is that a method can have no/one/multiple arguments separated by commas. I am not able to get a repeating expression for this. Help will be appreciated.

    Read the article

  • Java - String Pool

    - by Gogi
    What is meant by String Pool ? What is difference between the following declarations : String s="hello"; String s=new String("hello"); Is there any difference between the Storing of this two strings by JVM ?

    Read the article

  • deleting a file in java while uploading it in other thread

    - by user369507
    i'm trying to build a semi file sharing program, when each computer acts both as a server and as a client. I give multiple threads the option to DL the file from my system. also, i've got a user interface that can recieve a delete message. my problem is that i want that the minute a delete message receieved, i wait for all the threads that are DL the file to finish DL, and ONLY than excute file.delete(). what is the best way to do it? I thought about some database that holds and iterate and check if the thread is active, but it seems clumsy. is there a better way? thanks

    Read the article

  • java applet - array checking

    - by Dan
    OK so my code is here: http://www.so.pastebin.com/m7V8rQ2n What I want to know... let's say I have an image which I can redraw on tiles... is there a way to check for future tiles so I DON'T go out of bounds of my already defined tile map? Like if I were at the edge of a map... it would NOT let me go past it? Thanks.

    Read the article

  • java - find out the type of class which implements of other classes

    - by Johnzzz
    i have a kind of specific problem, let's say, that i have public interface A { } //------------------------------ public class B implements A{ static int countx = 0; } //---------------------------------- public class C implements A{ static int county = 0; } //---------------------------------- public class Arc { public A from; public A to; //======================================== and now I have an object a (which is an instance of Arc) and I want to find out whether it is an instance of B or C and get to the atributes countX or countY (stg like a.from.countX) any ideas? :)

    Read the article

  • Java: How to make this Serializable?

    - by Hasslarn
    I dont know that much about Serializable, but i need this class to be. How to achieve it? package helpers; public class XY implements Comparable<XY> { public int x; public int y; public XY (int x, int y) { this.x = x; this.y = y; } public int compareTo( XY other ) { String compare1 = this.x + "-" + this.y; String compare2 = other.x + "-" + other.y; return compare1.compareTo( compare2 ); } public String toString() { return this.x + "-" + this.y; } } As of now i cant send it as an object with outputstream..I´ve tried just to implement Serializable but it doesnt do the trick!

    Read the article

  • Singleton & Multithreading in Java

    - by vivek jagtap
    What is the preferred way to work with Singleton class in multithreaded environment? Suppose if I have 3 thread, and all they try to access getInstance() method of singleton class at the same time - What would happen if no synchronization is maintained? Is it good practice to use synchronized getInstance() method or use synchronized block inside getInstance(). Please advise if there is any other way out.

    Read the article

  • Adapting pseudocode to java implementation for finding the longest word in a trie

    - by user1766888
    Referring to this question I asked: How to find the longest word in a trie? I'm having trouble implementing the pseudocode given in the answer. findLongest(trie): //first do a BFS and find the "last node" queue <- [] queue.add(trie.root) last <- nil map <- empty map while (not queue.empty()): curr <- queue.pop() for each son of curr: queue.add(son) map.put(son,curr) //marking curr as the parent of son last <- curr //in here, last indicate the leaf of the longest word //Now, go up the trie and find the actual path/string curr <- last str = "" while (curr != nil): str = curr + str //we go from end to start curr = map.get(curr) return str This is what I have for my method public static String longestWord (DTN d) { Queue<DTN> holding = new ArrayQueue<DTN>(); holding.add(d); DTN last = null; Map<DTN,DTN> test = new ArrayMap<DTN,DTN>(); DTN curr; while (!holding.isEmpty()) { curr = holding.remove(); for (Map.Entry<String, DTN> e : curr.children.entries()) { holding.add(curr.children.get(e)); test.put(curr.children.get(e), curr); } last = curr; } curr = last; String str = ""; while (curr != null) { str = curr + str; curr = test.get(curr); } return str; } I'm getting a NullPointerException at: for (Map.Entry<String, DTN> e : curr.children.entries()) How can I find and fix the cause of the NullPointerException of the method so that it returns the longest word in a trie?

    Read the article

  • Reference variable to an object instantiated/initialized in another class in Java

    - by Alex
    The reason I'm asking is because I'm getting NullPointerException. I now this is very easy but I'm pretty new programming and find this a bit confusing. So say I have initialized an object in a class and want to access that same object from another class. Like now for instance I'm working on a small Chess game, in my model Game class I have an instance of Board, an object. Board, in turn, has an array of Squares. Square[][]. Game has board, board has Square[][]. Now if I want to access the Square[][] through the object board (in Game) of type Board. Do I just declare a variable with the same name and type or do I have to initialize it again? Board board OR Board board = new Board(); Note, I have already initialized board in the class Game so if I do it again, won't they be two totally different Board objects?

    Read the article

  • Java Generics Issue (w/ Spring)

    - by drewzilla
    I think I may be a victim of type erasure but thought I'd check with others here first. I have the requirement to do something like this: public interface FooFactory { public <T extends Bar> Foo<T> createFoo( Class<T> clazz ); } It is perfectly valid to write this code. However, I'm trying to implement this functionality using a Spring BeanFactory and I can't do it. What I'd like to do is this... public class FooFactoryImpl implements BeanFactoryAware { private BeanFactory beanFactory; public <T extends Bar> Foo<T> createFoo( Class<T> clazz ) { return beanFactory.getBean( ????????? ); } public void setBeanFactory( BeanFactory beanFactory ) { this.beanFactory = beanFactory; } } As you can see, I've put in ???????? where I'd like to retrieve a bean of type Foo<T>, where T extends Bar. However, it is not possible to derive a Class object of type Foo<T> and so I assume what I'm trying to do is impossible? Anyone else see a way round this or an alternative way of implementing what I'm trying to do? Thanks, Andrew

    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 | 320 321 322 323 324 325 326 327 328 329 330 331  | Next Page >