downgrading java version on the fly

[jjunos]

Hello all,

I was wondering if there's a way to add a java version to update-java-alternatives.

I currently need both java 1.4.2 and Java 6 for two seperate projects, but flipping between the two is a hassle. I've set it up in my bashrc at the moment, but i know that:

/usr/bin/java -> etc/alternatives/java -> my java home

What i'd like is to (from reading online in a few places) do a

sudo update-java-alternative -s <javaversion>

when i need java 1.4.2, or java 6. But whe ni do a

sudo update-java-alternative -l

I can only see my java 1.6. I manually installed the java 1.4.2 (since it's not in the repo). Idea's on how to add it to update-java-alternatives?


Thanks,
JJunos

[Zorael]

I know you can do it with the normal update-alternatives, not sure how you do it with update-java-alternatives.


$ sudo update-alternatives --install /etc/alternatives/java java /usr/lib/jvm/java-version/java 0
Change the last integer to give it another priority when autodetecting which should be used, such as when calling it with --auto java.

List installed alternatives with 'update-alternatives --list java'. Set it with --set. And of course, spawn a menu with --config.

$ sudo update-alternatives --set java <path to java executable added earlier, listed with --list>
Omit sudo to make it a user-specific alternative.

If it gets botched up somehow (happens), just do '--remove java <path to executable>'. If it gets *really* botched up, manually edit /var/lib/dpkg/alternatives/java; Karmic seems to get stuff wrong on occasion, for one.