can anyone tell me how to set the environment variable on linux so that it can just run the java or javac command only!!

=============================
/usr/java/j2sdk1.4.2_04/bin/java HelloWorld
|
V
java HelloWorld
=============================

I have append the line at /etc/profile
#set java environment
export PATH=$PATH:/usr/java/j2sdk1.4.2_04/bin
export JAVA_HOME=/usr/java/j2sdk1.4.2_04
export CLASSPATH=/usr/java/j2sdk1.4.2_04/lib:$CLASSPATH:.





the following code works but I don't understand need to specify the whole path to run java and javac at php

$last = exec("/usr/java/j2sdk1.4.2_04/bin/javac $filename", $output);
$last = exec("/usr/java/j2sdk1.4.2_04/bin/java HelloWorld",$output);




<?php

if(!defined('_DEBUG_')) define('_DEBUG_',1);

if(_DEBUG_)
{
header('Content-type: text/plain');

ini_set('display_errors','1');
error_reporting(E_ALL);
}
$filename = "HelloWorld.java";
$last = exec("/usr/java/j2sdk1.4.2_04/bin/javac $filename", $output);
if(_DEBUG_)
{
echo $last."\n";
print_r($output);
}

$last = exec("/usr/java/j2sdk1.4.2_04/bin/java HelloWorld",$output);
if(_DEBUG_)
{
echo $last."\n";
print_r($output);
}

?>

the PATH depends on which user start httpd ie :
add export PATH=$PATH:/usr/java/j2sdk1.4.2_04/bin to your ~/.bashrc
create a infos.php file, put in it : <?php phpinfo(); ?>, place the file in your site directory

sudo /sbin/apachectl start
With a web browser go to www.yoursite.com/infos.php
and look at the PATH indication, it should have /usr/java/j2sdk1.4.2_04/bin in it