we are new to Ubuntu.Recently we changed my server OS to ubuntu 12.04 from windows 7 . every one have their own login details. one of my college installed Open-Jdk7. I asked him, where you installed JAVA, then he suggested to switch the following directory

su root
cd /usr/lib/Jvm

Totally 3 folders are there in JVM folder. names are.

1. java-1.7.0-openjdk-amd64

2. java-7-openjdk-amd64

3. java-7-openjdk-common

generally, If you install Java in Windows, we will get 2 folder. 1 folder is for JDKand another points to JRE.

but, in Ubuntu we have 3 folders. is it right?

for my conformation, whether he installed correctly or not. I open Terminal. I run the following 2 commands

 javac
 java -version

both commands are working fine.

now I want to set-up Java-Home and Path for all users at same place.because everyone is working on Application server.

Can anyone explain step-by-step.

Thanks.