Thursday, October 31, 2013

Installing java on your linux machine without removing the native version it comes with

I like to have all my software installations in a single place so I know exactly what state my machine is in by glancing at a single directory, say ~/Software
My ancient CentOs setup doesn't have jdk 1.7 in its repo, so instead of fooling around with alternatives <shudder>, I downloaded the jdk version I wanted and put it into said ~/Software directory.

Here's a simple way to go about changing the default version of java that your system picks up without having to uninstall the native java that it comes with.

1. Switch to su
2. Create a file,say in /etc/profile.d/ containing :


3. Save out the file, and logout and log back in to your machine.
4. To test out your java version, run
java -version
5. To see which executable will be picked up, run
which java