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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

 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.


share|improve this question
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. – Danatela Jul 18 '13 at 7:55
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 – ur truly friend Jul 18 '13 at 11:07
I see you came from Windows world :) There is no need to change PATH variable. Just add JAVA_HOME and JDK_HOME if some application requires them. – Danatela Jul 18 '13 at 11:16

Installation of Oracle Java:

  1. Donwload the tarball from Oracle website
  2. unzip it by 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

  1. restart the machine and check by java -version and javac -version
share|improve this answer
sudo gedit /etc/environment

then add these lines

JAVA_HOME = ":usr/lib/jvm/java-7-openjdk-amd64/bin"
CLASSPATH = ":usr/lib/jvm/java-7-openjdk-amd64/bin:/home/something etc whatever you want etc" ( separated by semicolon )
share|improve this answer
JAVA_HOME should point to a java installation folder, not its bin subfolder. And what's with those colons? – Marko Bonaci Oct 19 '13 at 22:25

Edit the system Path file /etc/profile

sudo -H gedit /etc/profile # always use -H when you sudo a gui program or anything else which might write config files to the $HOME directory.

Add following lines in end

export JAVA_HOME
export JRE_HOME
export PATH

For complete installation guide..

share|improve this answer
i tried this but still got the same error – Nitesh Verma Dec 8 '14 at 8:35

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