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

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



read inputstream works in office, not at home
senderj — Sun, 11 Dec 2011 22:26:59 -0500
I use NetBeans both at work and at home, v7.0.1. Recently, I developed a small program using HttpURLConnection to read web page and process the contents. It works fine in my office, but not at home! In the office, the whole html code is listed. At home, it stopped in the middle with socket reset or freeze forever. After many testing, I summarize my finding here:
With higher chance (but not always) of success:

1. use read(byteArray, offset, length)

2. use byteArray size = inputStream length

3. write the byteArray to file immediately

4. small inputStream size (e.g web page small) 

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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



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



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



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



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



sahi framework
ejaenv — Tue, 13 Sep 2011 06:03:21 -0400
you forgot sahi framework, which falls in the category of IDE and scripting
JW Talkback



Limited mainly to untrusted applets
metatech — Fri, 02 Sep 2011 10:13:51 -0400
Although the article does not mention it explicitly, these recommndations are primarily aimed for applications running as untrusted applets in a browser.  Trusted applets or applications using the normal system classpath (Java desktop applications or Java EE applications) can anyway use the Java reflection API to bypass most of those restrictions (by calling for instance "setAccessible").
JW Talkback



great article!
clin — Mon, 25 Jul 2011 17:32:31 -0400
great article!
JW Talkback



DevOps will lead to a new set of dev and test tools
sancheti — Wed, 13 Jul 2011 01:26:51 -0400
Very well written. DevOps will make applications reflect user behavior more closely with application changes all the time. The dev and test tools for continuous development are just becoming mainstream. We have just launched the first performance testing solution for DevOps - blitz.io - which you will soon see integrated in the leading PaaS platforms.
JW Talkback



Oracle open source
calvin77becker — Sat, 02 Jul 2011 00:23:04 -0400
i think you are right, Oracle open source should focus for making money rather to see big empires.
regards,
JW Talkback



How to associate couple of programs, each to its needed java .
isotoper — Sun, 26 Jun 2011 03:48:18 -0400
Hello,

We have about 6 products who uses java.

Every product needs its own java version and distributor (java sun, java IBM ...).

How should I configure that every program will get and use the specific java it needs ?
Thanks !!
Core Java



Java Application
pedrito287 — Wed, 22 Jun 2011 09:11:34 -0400
Hi all,
I'm in the process of creating a java application for users to create electronic timesheets.  After I'm finished with coding, how can i make my program a file that users can run on their machines as an actual application?  
Users are all using Microsoft XP if it matters.
Community Discussion



Good
pararudalf — Sat, 28 May 2011 00:45:19 -0400
Hi
I really liked it and thanks for sharing.
JW Talkback



source code
andhika_rahmad — Fri, 29 Apr 2011 19:33:44 -0400
I need some source code get I can learned if you can help me some  more i will grateful.( espcially java code)
sent to :ars_telkom@yahoo.com

cc: andhika_rahmad@plasa.com
JW Talkback



Oops rules conflict
nandhakumar — Wed, 27 Apr 2011 08:44:28 -0400
The getDeclaredFields() method in the package called java.lang.Class  returns all the declared variables inside a class including private variables. But as per the rule of Oops concept a private variable should not get accessible at the outside of the class.
can any one give a clarification about this.?
Tools and Methods



Dynamic check boxes in java
Fatema Mohsen — Fri, 22 Apr 2011 10:05:11 -0400
I was asking how could i create dynamic check boxes in java on a button press,especially without knowing the bounds of each check box.Then remove all checked boxes on another button press.Here is my manually created check boxes code

cb1=new JCheckBox("Task 1");
cb2=new JCheckBox("Task 2");
cb3=new JCheckBox("Task 3");
cb4=new JCheckBox("Task 4");
cb5=new JCheckBox("Task 5");
cb6=new JCheckBox("Task 6");
addTask= new JButton("Add Task");
removeTask= new JButton("Remove Checked");
addTask.addActionListener(this);
removeTask.addActionListener(this);

Core Java



JavaOne 2011
t3chno — Tue, 19 Apr 2011 03:05:52 -0400
My development team is largely Java based. I am aware of Devoxx and would hope to attend next year, but what are the other conferences that would be useful for my requirements?
Mobile Java



Judges face
OrganizedDocs — Wed, 13 Apr 2011 04:00:34 -0400
I would like to see judges face when he try to understand what's the class and what's the object :)
JW Talkback