JAVA_HOME change automatically in Linux

Question

I set my JAVA_HOME path by using the command:

export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-i386/jre/bin/java

Then when I use this: echo $JAVA_HOME I get:

/usr/lib/jvm/java-7-openjdk-i386/jre/bin/java

But when I close the terminal, and then open it and check echo $JAVA_HOME , the command will not get any result. That is, there is no JAVA_HOME set.

Answer 1

export only makes available the variable to the current and child processes, it is cleared, when you terminate your process.

You may put your export command into your ~/.bashrc file to have it always available.

So, open your ~/.bashrc file with a text editor, and put this into the first line:

export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-i386/jre

save the file, and after a relog, you can always use the veriable in shell scripts.

Other option (actually the recommended one by Ubuntu documentation ) is to put this line into /etc/environment , this way the variable will be set for all users.

Answer 2

to know java version use, java -showversion

To verify java path is set or not use echo $JAVA_HOME

Use following command to set java path

sudo gedit /etc/environment

In the file set JAVA_HOME

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
JAVA_HOME=/usr/lib/jvm/java-7-oracle/jre/

remember to provide the path completely upto the folder which contains bin/java .

Restart system to activate the changes.