How to set the default Java version

I have been using Java 6 on Ubuntu 11.10, but now I want to update to version 7. I've installed version 7 via PPA as described here. If I run

sudo update-alternatives --config java

I get the following output:

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

  Selection    Path                                     Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-oracle/jre/bin/java   64        auto mode
  1            /usr/lib/jvm/java-6-sun/jre/bin/java      63        manual mode
* 2            /usr/lib/jvm/java-7-oracle/jre/bin/java   64        manual mode

Similarly, if I run:

sudo update-alternatives --config javac

I get the output:

  Selection    Path                                  Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-oracle/bin/javac   64        auto mode
  1            /usr/lib/jvm/java-6-sun/bin/javac      63        manual mode
* 2            /usr/lib/jvm/java-7-oracle/bin/javac   64        manual mode

So it looks like version 7 is already the default. But if I run either

java -version

or

javac -version

The output indicates that version 6 is still the default. How can I set the default to version 7?

As per this answer: How to set default Java version?

Try providing the explicit path along with update-alternatives --install first, and then run update-alternatives to make your selection:

sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/java-7-oracle/jre/bin/java" 1

sudo update-alternatives --config java

sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/java-7-oracle/bin/javac" 1

sudo update-alternatives --config javac

You need to set javac too.

sudo update-alternatives --config javac

I had the same problem. I had sun jdk6 installed. After

    sudo update-alternatives --config java
    sudo update-alternatives --config javac
    sudo update-alternatives --config javaws

a restart was necessary for me. Than it worked.

Edit: I realized it was not enough to do the steps above.

I also had to edit the environment variable:

    sudo nano /etc/environment

And add (a different java version will require a different string) :

    JAVA_HOME="/usr/lib/jvm/java-7-openjdk-amd64"