How to setup Java-Home and Path in Ubuntu 12.04

Question

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.

Solution

Installation of Oracle Java:

1. Donwload the tarball from Oracle website

2. unzip it using this command:

   sudo tar -xvpzf fileName -C /installation_folder_name`
   

3. change the files permission and ownership

4. add the following two lines in /etc/profile

   export JAVA_HOME=/home/abu/Java/jdk1.8.0_45/
   export PATH=$JAVA_HOME/bin:$PATH
   

5. restart the machine and check by java -version and javac -version

Comments

[Danatela]

The best way to setup environment variables for all users is editing /etc/environment file. It has pretty simple syntax. And to setup user-specific environment variable you should edit ~/.bashrc file. Add the export VAR=value to the end of this file.

[ur truly friend]

I mention like this. PATH=PredefinePaths:/usr/lib/jvm/java-7-openjdk-amd64/bin JAVA_HOME="/usr/lib/jvm/java-7-openjdk-amd64". I didn't mention any special charachers in between Path and JAVA-HOME variables. Is it right, What I did

[Marko Bonaci]

JAVA_HOME should point to a java installation folder, not its bin subfolder. And what's with those colons?

[Nitesh Verma]

i tried this but still got the same error