Ubuntu Tips

JAVA_HOME Errors

When you final setting up JAVA_HOME, you are supposed to set its path in two different places:

1. ~/.bashrc: You will see something like export JAVA_HOME="/usr/lib/jvm/java-8-oracle". Note there are double quote sign in path, and there is no space between JAVA_HOME and path.

2. /etc/environment (Read Only): You will see something like JAVA_HOME="/usr/lib/jvm/java-8-oracle". Note: *there is double quote for path, and there is no space between JAVA_HOME and path*. This is a read-only file and you need to be admin if you want to modify it.

If your JAVA_HOME is not correctly set up, you may get following error in you Ubuntu:

Cannot Update/Remove Software

You can find a official forum here.

One of my application, xpad, cannot be removed because of this. When I run sudo apt-get remove xpad, a error message install-info can fail to install due to syntax errors in /etc/environment appears.

I check my /etc/environment file. It turns out I had extra spaces in my JAVA_HOME, which cause the problem.

Also, if your software updater in Ubuntu failed to download necessary packages, you may have a wrong setup of JAVA_HOME.

Reminder in Terminal

When you open terminal, you may get some error message such as bash: export: ``/usr/lib/jvm/java-8-oracle': not a valid identifier. In this case, you need to check your ~/.bashrc file to make sure your JAVA_HOME format is correct.

If you forget extact format of JAVA_HOME, you can open ~/.bashrc file using gedit, then following the format of other variables. You can varify by checking the color highlight of your JAVA_HOME line should be the same as all lines above.