Ubuntu – JREs from different vendors on the same system

javajrepackage-management

In various tutorials, it is said, that you should remove existing JRE/JDK before installing new one (e.g. remove OpenJDK before installing the one from Oracle).
Is it really necessary? I remember having 2 JREs at one point, being able to choose in my IDE which to run program on.

Don't remember to have any conflicts, what's the chance of having any?

Best Answer

You can install multiple JRE/JDK at a time. You just need to configure which one to use by using update-alternatives

sudo update-alternatives --config java

There are 2 choices for the alternative java (providing /usr/bin/java).

Selection Path Priority Status

0 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 auto mode

1 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 manual mode

* 2 /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java 1051 manual mode

Press enter to keep the current choice[*], or type selection number: 1

Similarly, you can configure your JDK with

sudo update-alternatives --config javac

Related Solutions

Software Installation – Setup and Install IntelliJ with JDK

This should get you started:

#!/bin/sh

add-apt-repository ppa:webupd8team/java &&
apt-get update &&
apt-get install oracle-java7-installer &&
echo oracle-java7-installer shared/accepted-oracle-license-v1-1 select true | sudo /usr/bin/debconf-set-selections &&
update-java-alternatives -s java-7-oracle &&

wget -O /tmp/intellij.tar.gz http://download.jetbrains.com/idea/ideaIC-12.0.4.tar.gz &&
tar xfz /tmp/intellij.tar.gz &&
cd idea-IC-123.169/bin &&
./idea.sh

Some things you should consider:

I'm not sure at which part the echo oracle-java7-installer shared/accepted-oracle-license-v1-1 select true | sudo /usr/bin/debconf-set-selections has to be. Might be a line earlier.
The line cd idea-IC-123.169/bin is dependend on the IntelliJ version, as the extracted folder is named in that way. It only works with the version available while I'm writing this.
Same goes for the download link. It might change with a newer version.
I'm not sure what happens if you try to add a ppa that already exists again. This could lead to problems.
You have to execute the script as root

Best Answer

Related Solutions

Software Installation – Setup and Install IntelliJ with JDK

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