Setting up JAVA_HOME on Ubuntu

In the following post, we will follow steps to set up JAVA_HOME for our environment.

First, become root

$ sudo su

and enter password

Next check java install folder

$ which java

However this is just the symbolic link. To find the actual folder, we will use the following command.

$ readlink -f $(which java)

Now we will create a new symbolic link for the actual folder within /usr/lib/jvm called default-java pointing to my Oracle JDK in this case. This will allow me to re-point the symbolic link to any future versions if needed.

$ cd /usr/lib/jvm
$ sudo ln -s /usr/lib/jvm/jdk1.8.0-oracle default-java

Next, go back to home and open the .bashrc file in editor

$ cd 
$ gedit .bashrc

Add the following lines at the end of the file

JAVA_HOME=/usr/lib/jvm/default-java
export JAVA_HOME
PATH=$PATH:$JAVA_HOME
export PATH

Now save and close this file, and close the terminal

Open a new terminal using Ctrl-Alt-T

Enter the command

$ echo $JAVA_HOME
$ java -version

You should see the JAVA_HOME as well as version of Java installed. This way of setting up can allow you to update the current JVM using update-alternatives command. So see how to configure using update alternatives, refer to my previous post.

 That's it!