Java Beginner

ActionEvent constructor

VonQ — Sun, 18 Oct 2009 15:31:53 -0400

Hello. I am a Java beginner and was wondering where I could find the constructor for the ActionEvent class, since I am learning about button events. I want to know what an object of ActionEvent class does in response to the button click on an applet.

Java Beginner

Decode a g721 audio stream with java

xmen — Wed, 14 Oct 2009 05:09:21 -0400

Hello,

For the purpose of a project, I need to capture a live feed from a Panasonic BL C131 IP cam. The video is encoded either in MPEG4 or in MJPEG, and I can manage to get and display the stream. The sound stream in the other hand is encoded in g721 (now superseded by g726 - 32kbits/s - 8Khz - 4 bits of quantification), and I don't how to decode it. Has anyone already struggled with this issue ? I'm opened to suggestions and/or solutions. Thanks.

Regards,

Ariel

Tools and Methods

Comm api 2.0 - CommPortIdentifier.getPortIdentifiers() returns empty enum

eyalm_nm — Wed, 30 Sep 2009 13:14:24 -0400

Hi,
I'm trying to open connetion with my GSM modem which it connected to my PC by RS-232 cable.
I'm trying to run my program on Windows XP.
But, when i'm running the following piece of code, the enumeration return empty.
How it can be solved?

Enumeration en = CommPortIdentifier.getPortIdentifiers();
System.out.println(en);

// Iterate through the ports.
while (en.hasMoreElements()) {
    portId = (CommPortIdentifier) en.nextElement();
    if(portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
         System.out.println(portId.getName());
    }
}

Tools and Methods

Event Reservation Problem

prasath_arjunan — Mon, 31 Aug 2009 06:27:26 -0400

Dear Users.

I am doing a online Conference Hall booking system with JSP and MySql. I have the following problem when I (as Admin) am going to approve the some event on Same date(2009-08-29).

My application is to reserve a room by entering start time, end time and date before reserving I need to check the availability in the database.
When i'm requesting reserving by entering(selecting) startime as 17.30 and end time as 20.00 on a particular date(2009-08-29),

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Tools and Methods

Problem with euro symbol with Tomcat and MySql

serrani — Thu, 06 Aug 2009 17:02:08 -0400

Good day. I have a big problem regarding the euro symbol between Tomcat and MySql. I made a jsp page having a form that contains a textarea. In it I digit the euro symbol. The action of a form call a Tomcat's servlet that read a value of the field and write it in a MySql's table via jdbc. The problem is that in the database the euro symbol is written as ? (question mark). The environment is a Linux in english with Tomcat 6.0.10 and MySql 5.0.18.

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Tools and Methods

Core Java Design Problem

chat2anuj — Thu, 16 Jul 2009 05:35:30 -0400

Hi All,

I am stuck with this java design problem and need your help on this.

#####################################################
A diamond has 3 attributes and possible values as

Clarity (Y1, Y2, Y3 ......... Y25)
Color (C1, C2, C3 ......... C9)
Carat (T1, T2, T3 ......... T50)

A diamond company deals in diamonds and has definite clients who purchase diamonds from this company.

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Tools and Methods

JSP Thumbnail View

prasath_arjunan — Tue, 02 Jun 2009 01:11:39 -0400

Hi All,

I'm working on a photo gallery application in JSP and have encountered a problem trying to create thumbnails from large photos.

Basically I'm trying to create thumbnail images on the fly(image file should not save to the hard disk) to serve up to the users via the JSP script.

Is it possible to do in jsp(with html)?
Does anybody has idea or source? Please let me know.

Thanks in Advance,

V. Prasath.

Java Beginner

Java Online Source Library

ruochang — Sun, 10 May 2009 23:56:45 -0400

Recommend one Java online source code resource website:
http://www.techq.com>
Including JDK, Spring, Struts, WebWork and many open source code.

Tools and Methods

Method chaining question

VonQ — Mon, 04 May 2009 19:02:16 -0400

In this example:

object.method1().method2().method3();

What gets evaluated first? Does method 2 use what method 1 returned first for its calculation, or does method 3 return what method 2 returns for its calculation and then evaluate the first method based on what that returned?

If the question is not clear I will clarify.

Thanks, Von

Java Beginner

The CookieStore

lemon3_82 — Mon, 13 Apr 2009 09:18:53 -0400

I just stumbled upon this keyword when i was searching
the .net api for Java SE 6 thought it was fun to read

java.net

Interface CookieStore

public interface CookieStore

A CookieStore object represents a storage for cookie. Can store and retrieve cookies.

CookieManager will call CookieStore.add to save cookies for every incoming HTTP response, and call CookieStore.get to retrieve cookie for every outgoing HTTP request. A CookieStore is responsible for removing HttpCookie instances which have expired.

Think about it how many times have you tried to eat a cookie and never

Tools and Methods

Prefix and Postfix operator question

VonQ — Wed, 01 Apr 2009 20:37:19 -0400

There doesn't seem to be any difference in the output when I change the prefix to the postfix operator for the following code:

public class inc

{

public static void main(String[]args)throws Exception

{

for(int val=1; val< 11; val++) //when I change it to ++val the output is the 
                               //same

{

System.out.println(val);

}

}

}

Why use one or the other if there is no difference in output?

Thank you from Von, a struggling Java student

Java Beginner

Instantiating object in main method

VonQ — Mon, 23 Mar 2009 17:10:13 -0400

This is a really, really dumb question but I'm trying to wrap my mind around why all my beginner java books use the main method to instantiate objects of a different class than the one it is being instantiated in, such as the one below. I've tested it and know it works but why don't I ever see it in the books? Is there a drawback to creating a new object of the same object that you are in?

Thanks, Von and sorry if this is a crazy question!!!!!!


public class TestClass

int id = 6;
{
    public static void main(String[] args)
     { 

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Java Beginner



Convert vector image to XML
Thanushka — Thu, 19 Mar 2009 01:37:27 -0400
Hi,
I need to convert a vector image to XML and also to convert XML data to a vector image in the back end.
Can someone advice me and help me about how to do that?
Thanks in advance.
Enterprise Java



Predictive text (Cell phone)
cyrow — Sat, 21 Feb 2009 06:49:03 -0500


[code]import java.io.*;

import java.util.*;

class HomeWork1{

 static String[]list = new String[100];

 public static void main(String[] args)throws IOException{
 Scanner in = new Scanner (new FileReader("input.txt"));

 PrintWriter out = new PrintWriter (new FileWriter("output.txt"));
 String []num = new String[100];

  int z = 0;

   String str = in.next();
      while(!(str.equals("$$$$"))){

       list[z] = str;

       num[z] = getWord(str);

       z++;

       str = in.next();

      }
 insertionSort(list,0,z);

for(int i = 0; i < z; i++){ 

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Tools and Methods



Cannot compile Java Class.
satyadmv — Fri, 13 Feb 2009 00:14:34 -0500
I have installed java into D:/Program Files/Java

I opened the command prompt.Reached C:\.

I have a Test.java file in C:\.

Now when i run the command javac Test.java , it throws and error saying javac not found.
I copied the same Test.java to D:\.

In the cmd prompt i set the current directory as D:\.

Now i ran the cmd javac Test.java, it worked.
May i know the reason for getting this error in the first scenerio.

I couldnt understand the reason why it happened.
Java Beginner



Generating XSD from XML
knagap — Wed, 28 Jan 2009 00:02:26 -0500
As per my client requirements, I have to generate XSD from an existing XML through java. Any suggestions on this will be appreciated.
Tools and Methods



java.lang.outofmemoryerror
jignesh — Fri, 02 Jan 2009 14:24:14 -0500
I am getting "java.lang.outofmemoryerror" , when I am trying to access an application. It looks like memory space is running short. How can I check what existing heapsize memory is ? Sopmebody advised me to use "java -Xmx" on the command line. I am not sure whats the current heapsize memory is. So how can I check this ?
thanks
Java Beginner



Top Java Developers Offer Advice to Students
Youssou — Wed, 10 Dec 2008 20:29:37 -0500
Got Advice for Students? 
A very good java.sun.com article

(http://java.sun.com/developer/technicalArticles/Interviews/studentdevs/i...)

has 11 leading Java developers -- from Joshua Bloch to Tor Norbye to Chet Haase -- offering advice about how to become better developers. It's very useful if you're trying to figure out how to make it as a Java developer.
Here's a brief sampling:
Josh Bloch: 

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Java Beginner



xml problem need help.....
umaj — Mon, 01 Dec 2008 00:12:35 -0500
hello i have question abt xml using DOM....i have that xml 
<?xml version="1.0" encoding="UTF-8"?>telenorWaridPaktelltelenorWaridPaktell
i want that to delete  so my required xml look like that 

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Java Beginner



How to print a PDF file in Java?
venkatsalem — Sat, 22 Nov 2008 22:16:11 -0500
Tips for enterprise java developer.
Sometime back I was looking for a solution to send a PDF document to printer from server side programming. Found a solution using PDF Renderer open source. For your benefits, documented my finding in below link. Hope all of you can benefit.

http://venkatsadasivam.wordpress.com/2008/11/03/java-print-pdf/
Java Beginner



Jsp Watermarks
prasath_arjunan — Thu, 20 Nov 2008 08:02:32 -0500
Hi Guru's,
I am developing a website for matrimony, i want to add the text (like copyright @ company)

on image when the user uploading their photo.  I got one program from internet, it is working

perfectly as a java program, but it doesn't work after i converted into jsp.  I couldn't find

solution what is the problem in that code. I am using JDK1.5.0_06 and Tomcat 6.0. Please

look over my two program. Its throw me an error when i execute that jsp program(Watermark.jsp).
The Error is:
Error Occurred : javax.imageio.IIOException: Can't read input file!

 

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Java Beginner



if..else exercise question
stsermen — Mon, 10 Nov 2008 06:27:19 -0500
Hello, i have a question about the following code. I'll appreciate it if someone can help me out.
When i first tried to execute this code it gave me the error:
"The local variable animal may not have been initialized".
I thought I've initialized the variable for each if block so I re-checked the code and realized that: 
if(hoursHome > 2) (shown below) was an extra and unnecessary sentence, 

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Java Beginner



Loading from classpath dont work
Fri, 31 Oct 2008 12:02:07 -0400
ClassLoader loader = ClassLoader.getSystemClassLoader();

		System.out.println(loader.getClass().getName());

		InputStream in = null;
		if (loader != null) {
			URL url = ClassLoader.getSystemResource("com/comp/resource/workflow.properties");
		
			String path = System.getProperty("catalina.home") + File.separator+ "workflow.properties";	
			System.out.println("Path"+path);
			if (url == null) {
				in = loader.getResourceAsStream("com/comp/resource/workflow.properties");

				if (in != null) {
					props = new Properties();
					props.load(in);
 

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harpreet.your@gmail.com
Fri, 31 Oct 2008 06:50:54 -0400
i m harpreet my problem related to native method, wt is the use of this method..
JW Talkback



need help
Wed, 22 Oct 2008 14:04:59 -0400
Explain the purpose of the following statement. 
public void actionPerformed(ActionEvent event)

JW Talkback