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My question starts with the toArray() method of the Collection - from this I get an Object[] back. However I know that each of the elements in the Collection is a String object, so I figured the obvious thing to do would be to cast it so:code:String[] strings = (String[]) collection.toArray();Wh...

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Hello Ranchers! I want to change the default implementation of some method which will be members of some built in class of java. Let's say length method of string class will return string insted of returning int. Now i find out the source of string class made the changes and compiles the sam...

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Hi I have to create a folder (named XYZ) in a servlet but i need to pass on the name when I build the web app . I want to give the folder-name in a properties file, and replace the folder-name in the servlet when am building the app through build.xmlQuestion:What to do in build.xml ?What to do i...

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hi everyone, There are many interfaces in jave. For example consider public interface RequestDispatcher. In this interface, there are 2 methods by name include() and forward(). We know that both the methods do some work when they are called. But seeing the interface, they look empty. Somewhere...

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Is it Possible to Implement a Interface at Runtime?...Something Like this...Class interface = Class.forName("interface Name");public Class implementInterface(Class interface){blah... blah...retrun (Class)}Please do clarify my doubt....thanksVivek...

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consider there is a program in which several threads are running.i want to modify the program in such a manner that when the main thread terminates all other threads have been terminated and i don't want to scan the file.Only i want to add some lines of code at the closing brace of main(like...

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Howdie:I have issues with this program:package Scores;import java.io.*;import java.util.*;import java.util.Scanner.*;public class Scores { public static void main(String[] args) throws Exception { int total=0; int count=0; // Create a File instance java.io.File file = new java.io.File("Scores.tx...

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actually i use system.out.println and log4j for debuggingis ther any other way to debug my webapplication?and what is the difference between System.out.println debug and log4j debug methods?please can any one tell me about this thanks in advance...

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Hi All,Help me out to find a solution to the below program.1) I have declared an array called student [] in main program2)I initialised the array inside the function void modifyRef().I can print the values inside the function.I need to get the values returned in the main function.3)But the const...

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implemented a bubble sort and all is well[ January 06, 2004: Message edited by: Tony Fabeets ]...

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How does this code work?...Outer o = null;Outer.Inner = o.new Inner();...where Inner is a non static inner class of Outer.Any ideas?...

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Hi All,What all software are required to run the Ant build tool.An example in this regard would beappreciated...

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Is HashSet generally known to be the fastest collection available in J2SE?I've setup a HashSet without about 1000 different numbers in it which I am just using to do a comparison to see if the number is in the collection.This works pretty well, but is it going to slow down significantly as t...

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code:interface Apple{int x=7;}class AppleClass implements Apple{ static int x; public static void main(String args[]) { System.out.println("x value"+x);}}answer is 0 ..what happens to interface variable x?...

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Hi Java masters,I'm facing some difficulties with a java quizz.Please give me some ideas.Quiz01 :The text file has three records like :JohnNO.123, HirLet Road,LL 234025-5-54551 5 0 2 7000PaulNO.23, Hello Road,LL 235025-5-54541 5 0 2 6000MaryNO.23, Mine Road,LL 23523-5-54541 5 0 2 9000Accordi...

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Hi-I have a requirement to print a record (data like : name, address etc) once the record is updated. I would have to write the code to get the printer name and path in the network from a properties file and then print the record using the same. Is there anyway I can do this using java.Please he...

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I have two classes. The first has 4 arrays I would like to use in the other class. What is the syntax for doing this I keep getting a nullpointer exception. The one class is called Final and the other is Project.for(int i = 0; i< Final.arr.length; i++){ g.setColor(Color.BLUE); g.drawOval((int...

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can anyone tell me how the following program works ..?public class TernaryAssertion{public static void assertBounds(int low,int high,int value){assert (value > low ? value < high : false) : ( value < high ? "too low" :"too high");}public static void main(String[]args){assertBounds(100,2...

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I have a series of Amazon EC2 instances I wish to hold the addresses for in my build.xml file. For a particular target I would like to loop through all of these addresses and issue a command to the server. I can do it for one at a time; but I'm not sure how to create the equivalent of a Coll...

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Hi all, Say i have a huge applicaiton. The problem is as follows :-1) unfortunately there is no unit test cases ie junit written.2) Now if some part of the project is changed. developer gonna check the whole application to know if everything it working and none is broken.3) So i was wondering if...

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Hi all,Can anybody offer a good book for Ant with examples of building and deploying Web and J2EE Applications?Thanks...

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My problem is I have two classes, one to receive a message continuously i.e. while(true) loop, whenever that socket(port) is contacted.I run the sending file in a nother window. I run a single bathc file to do so. source:[run.bat]--- javaw send javaw receive---The send program places a system...

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Just started learning log4j.I wanted to create log4j listener for my build file, hence started with the small one.code:<project name="Logger" default="main"><target name="main"> <echo> Echo task</echo></target></project>is the build file.I have log4j.propertie...

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hi, can anybdy help me how can i do date validations.im wrking with JDBC and im inserting a query into date field but its giving me errors.regardsmurali...

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Hey all, I really have a basic question which can be best described as shown below:- public class SomeClass{ public SomeClass(){ int x =20; } public static void main(String[] args){ SomeClass y = new SomeClass(); System.out.println(y.x); } this will give me compile error right. Is it because th...

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I am trying to model a quiz. I create a Quiz object. There are 4 different types of Quiz. Each quiz needs to calculate results...therefore each of the 4 Quiz objects should have a calculate() method. Because each has to have this method, I thought I would create either an abstract class or inter...

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Is it possible to pass in command line arguments to Maven?In my build process, I call my goal overnightBuild which performs the entire process. I want to change the process that you can pass in an argument that specifies which branch the build is to be run off. So is it possible to pass in somet...

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I'm trying to use Ant and XDoclet, and I get the following error:[ejbdoclet] javadoc: Cannot find doclet class xdoclet.DocletTask$DocletMain[ejbdoclet] 1 errorejbdoclet] BUILD FAILED: file :/code/Java/money/build.xml:43: Javadoc returned 1I have the xdoclet.jar in my project classpath. The...

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Hi,I'm having a strange error with the URL class. I have written some code to poll a certain URL every second...thereby verifying if the Internet connection is functional. The code is shown below.If I have a working Internet connection and run the code, it says the connection is working. If...

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NOTICE: This post is for entertainment, relaxation purposes only. It's a post about how to design a new feature to a MUD.This isn't a bug, nor am I asking for urgent help, just thought I'd ask some more experienced Java developers if this makes sense. I'll try to make this as log...

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