Core Java

Why float type cast

parveen.gupta.23091987 — Tue, 31 Jan 2012 07:10:53 -0500

in java why float we has to be type cast i.e. float a = (float)2.3; and and if 2.3 is consider as double then why there is a need for that ???

Community Discussion

Desktop java application or browsew based application

hamzaissa — Mon, 23 Jan 2012 12:43:16 -0500

we have an multichannel softphone application where we can do chatting ,video call, voice call, email, what type of software is the best
Desktop java application or browser based application

Core Java

Swing help: Japplet not displayed in browser

i.m.prashant.m — Sat, 21 Jan 2012 15:07:10 -0500

My RegApp.java file contains following code :

import java.applet.Applet;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

import java.awt.*;
/*

*/
public class RegApp extends JApplet implements ActionListener
{
JButton submit=new JButton("Submit");
JButton cancel=new JButton("Cancel");
JTextField cname=new JTextField(20);
JTextField ceid=new JTextField(20);

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Core Java

How to execute a Callable Statement

Ankit Pandey — Mon, 09 Jan 2012 02:18:36 -0500

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.sql.*;


public class JoinTest {

public static void main(String[] args) {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

	try {

		System.out.println("Enter name of emp");

		String name=br.readLine();

		Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

		Connection con= DriverManager.getConnection("Jdbc:Odbc:JoinTest","sa","micro123");

		CallableStatement stmt = con.prepareCall("exec getPhone name");

		ResultSet rs=stmt.getResultSet(); 

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Core Java



Java AVL tree
mgau0047 — Tue, 03 Jan 2012 07:42:12 -0500
Hi i am making an AVL tree and i am having some problems in the search method, because a null exception error is given when the program is ran. Here is my code. Can you pls implement for me the search method so the program will run. Thanks in advance
package testavltree;
import java.io.IOException;

import javax.swing.JOptionPane;
/**

 *

 * @author Rapapc

 */

public class TestAVLTree {
    public static void main(String[] args) throws IOException, Exception {

        System.out.println("your inorder traversal is:");

        AVLarray process = new AVLarray(); 

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Core Java



Ballistic Line help
mi_para — Fri, 16 Dec 2011 07:59:29 -0500
Okay so, here is what I have so far, I am constructing a program that will eventually take a user input angle and velocity and display the ballistic path of a notional projectile, sans friction and whatnot. 
I have yet to build the user defined variables, I am just trying to get the polyline to display in the frame with a pre-defined angle and velocity. Somewhere down the road I would like to animate this, but for right now I am just trying to make it display on a Canvas. 

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Core Java



Database data doesn't fill into JTable
neocorp — Tue, 13 Dec 2011 02:09:07 -0500
I've been working on this code for couple of days. My procedure on the database works fine but it doesn't fill into the table. I'm going through the code again and again but I can't find what's wrong... The error I get is: JavaNullPointerException and the line involving is the piece of code that returns notes.length. Here's a piece of my code:



private Object[][] notes = null;

setUpStatusColumn(noteTable, noteTable.getColumnModel().getColumn(2));

protected JTable createTable(GradesModel gradesModel) {

        return new JTable(gradesModel);

    } 

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Core Java



Text to speech without using TTS
sridharkosna — Thu, 08 Dec 2011 05:48:10 -0500
Hi All,

      My requirement is to convert a string value to speech without using TTS (freeTTs). how can i achieve this? can anybody give me some idea. it could be helpful.
Enterprise Java



Character.reverseBytes error!
stratosb — Thu, 01 Dec 2011 10:53:19 -0500
Hello,

I have written some code to encrypt the contents of a textfile by using the method Character.reverseBytes as shown below:


    try {

        reader = new BufferedReader(new FileReader(file));

        writer = new BufferedWriter(new FileWriter(outfile));

        String text = "";

        // repeat until all lines are read

        while ((text = reader.readLine()) != null) {

            String reverseText = "";

            for (int i=0; i 

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Core Java



Port Swing to JSP
ryafel — Tue, 15 Nov 2011 07:37:32 -0500
Is it possible to port an application that was written in swing to jsp?
I have an application that was written in swing, but now i need to make it web based. Can this be done without changing the swing interface?
Tools and Methods



Hibernate query for joining two tables.
lofa in — Mon, 14 Nov 2011 05:40:09 -0500
I need to join two tables User and Employee. And the query will be like,
List list = hibernateTemplate.find("from User u left join fetch u.employee e");
So what I have to do in the User,Employee POJO.

SQL requirement is SELECT userName,firstName from Employee as e LEFT JOIN User as u ON u.userId = e. userId.
Tools and Methods



regarding row reading from Mysql ..
krishna523 — Mon, 14 Nov 2011 01:33:50 -0500
i am trying to read rows from mysql database.like 
............

.........

while(rs.next){
x=rs.getstring("columnname");
}
my question is when a row is readed some action is to be perfromed.but in this case control goes to next row before completion of task.
how to handle it ,please help me if anyone aware of it.
Thanks ,

krishna umareddy.
Enterprise Java



popup Menu in Glasspane
plin — Fri, 11 Nov 2011 05:13:52 -0500
Hello,
I tried to use popup Menu in Glasspane but found some problem. When I right click on the frame the popup menu shown. If the popup menu intersected with the frame border, it worked fine. if the popup menu were inside the frame totally, I could not select the menu items. I tried to add "popup.setLightWeightPopupEnabled(false);". It did not do any good. The pouup menu worked fine if it intersected the frame border as before. But it would not show if the popup menu were inside the frame totally. Is there any way to fixed this? The program is listed below.
Thank you very much. 

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Core Java



How to manage a dbms with multimedia content in java - jdbc(client /server)
arunrajp — Mon, 07 Nov 2011 09:54:46 -0500
I am an old timer from the 90s so java7 is a bit of a shock to me as ima an SCJP for java 2 platform from 2000.
Please suggest the best way to manage a multimedia databse containg (*.jpg and *.au) files in a DBMS or RDBMS using JDBC for both client(Standalone java application) and server side(Servlets).
Enterprise Java



how can i solve this problem ?
naved — Fri, 04 Nov 2011 02:15:22 -0400
hi ,

i have a situation in my code where i need to delete an object

because , my problem is

i have a jtree , which is getting created each time user click a button

like  new jtree(); i m doing this because of my requirements

so each jtree object has Object filename = node.getUserObject(); which gives me what i have selected at tree selection listener's event

so suppose i have clicked a button 3 times so as a result i have 3 instance of jtree and each jtree object has fileName instance variable 

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Core Java



How to remove prefix from target namespace
hemant89 — Thu, 03 Nov 2011 03:28:29 -0400
Hi All, 
I am new to this forum.

I am working on java web services. I am using "wsdl2java" tool to create a java stub file.

In my wsdl file value of targetnamespace is "urn:HPD_IncidentInterface_Create_WS" but i want to remove this urn prefix from java stub file.

I can't change wsdl file as it is application generated so is there any way to do this. 
Thanks
Tools and Methods



Deploying Jackrabbit to JBoss AS 7
srikanth.s.nair — Thu, 20 Oct 2011 05:09:17 -0400
Here are step by step directions on how to configure Jackrabbit  to JBoss AS 7.
1. Create directory for the jcr deployment

$ cd $JBOSS_HOME/modules
$ mkdir -p javax/jcr/main
$ vi module.xml


Add the following snippet to the newly created module.xml file

<module xmlns="urn:jboss:module:1.0" name="javax.jcr">
  <dependencies>
  <module name="javax.transaction.api" export="true"/>
  </dependencies>
  <resources>
    <resource-root path="jcr-2.0.jar"/>
    <!-- Insert resources here -->
  </resources>
</module>


Copy the jcr-2.0.jar to 

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Tools and Methods



Setting Oracle Datasource in JBoss AS 7
srikanth.s.nair — Thu, 20 Oct 2011 04:06:54 -0400
Here are step by step directions on how to configure JBoss AS 7 to communicate with Oracle XE.
1. Create directory for the oracle driver deployment
$ cd $JBOSS_HOME/modules
$ mkdir -p com/oracle/ojdbc6/main
$ vi module.xml


Add the following snippet to the newly created module.xml file

<module xmlns="urn:jboss:module:1.0" name="com.oracle.ojdbc6">
  <resources>
    <resource-root path="ojdbc6.jar"/>
  </resources>
  <dependencies>
    <module name="javax.api"/>
  </dependencies>
</module>
 

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Tools and Methods



License Terms for Java Code @JavaWorld
sacgaw — Mon, 17 Oct 2011 13:06:12 -0400
Hi,

What are the License Terms for usage of code published on JavaWorld as an application ?

Thanks

-sacgaw
Core Java



Unable to create soft-link in ubuntu
r4jiv007 — Sat, 15 Oct 2011 02:31:03 -0400
hello,
i m writing an app in which i want to create soft-link of files. I m using java for that and my code is :-
public static void crtsftlnk(String trgt, String sftlnk)

{

try {

Process proc;

Runtime rt = Runtime.getRuntime();

proc = rt.exec("ln -s "+trgt+" "+sftlnk);

BufferedReader br = new BufferedReader(new InputStreamReader(proc.getInputStream()));
String line;

while ((line = br.readLine()) != null)

{

System.out.println(line);

}

} catch (Exception e)

{

//e.printStackTrace();

}

} 

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Tools and Methods



How do I access the POI Jakarta?
yjs1210 — Wed, 21 Sep 2011 15:16:57 -0400
Hi, I'm trying to write a program that needs to access excel
I've never worked with POI Jakarta before and I do not know how to import correctly
I downloaded poi-src3.8beta file and unzipped it and it spits out a folder.
what do i do with this?
I tried to import using statements

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import org.apache.poi.hssf.usermodel.HSSFSheet;

import org.apache.poi.hssf.usermodel.HSSFRow;

import org.apache.poi.hssf.usermodel.HSSFCell;
but none of them seem to work. 
how do i address this issue?
Core Java



Dynamic Loading of Classes
vddmanikanta@gmail.com — Wed, 21 Sep 2011 03:26:09 -0400
Hai everyone
I am having an application that includes two jars in its source path.

These two jars have same set(named) of classes.
For instance there are two packages: Package1 and Package2.

Both have same set of static classes.
When I have reference to one such static class class from MYCODE, it gives a compile time error. The compiler doesn't know from which Package should it consider.
It gives the following error while compiling:

Cannot resolve to a type.
How do I resolve it.

Thank you

Have a nice day
With regards

Mani
Core Java



Avoid a cast when using class literals
bonzo101 — Tue, 20 Sep 2011 08:07:13 -0400
Hello. I have a question on java type safety.
I have a method that accepts a class literal and (for sake of argument) returns an instance of any class (in fact there is slightly more to it). 
Example:
Circle c = (Circle)this.returnInstance(Circle.class);

//removed exception handling
private Object returnInstance(Class c) throws Exception {

		return c.newInstance();

	}
My question is - is there any way to avoid performing the CAST (here, on the Circle instance) in the calling code?
Many thanks,

B
Core Java



Copy text from EXCEL in to Java
redrasp12 — Tue, 13 Sep 2011 15:31:05 -0400
Daily grind at work requires me to copy and paste text in to a Java based company intranet web page. This is a labor intensive task due to the volume of data needing to be input. Using my mouse all day for this task is insane.
How is it possible to copy text from EXCEL and paste it in to a java based web page using VBA from Excel? Please describe as many characteristics of this process as possible and sources of potential VBA code.
Tools and Methods



Inheritence problem(a demo form Thing in java)
ljjy23 — Sun, 07 Aug 2011 03:25:04 -0400
while reading Thinking in java, I get confused when I saw the example below(the example is in page 290, Chapter polymorphism):

public class PrivateOverride{
private void f(){print("private f()");}
public static void main(){
PrivateOverride po = new Derived();
po.f();
}
}
class Derived extends PrivateOverride{
public void f(){print("public f()")}
}


the result is private f();

I have two confusions: 

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Core Java