This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
I am guessing that Arun wants to run two different versions of Java (e.g. Java 1.4.2 and Java 5). This would be done by setting the PATH variable suitably, or by hard-coding the path to the java.exe file.