Resolving version conflict between java and javac on Ubuntu

Question

I have a problem with my compiled Java application on Ubuntu. It throws UnsupportedClassVersionError. I am compiling with a higher JDK version than the one that is

Answer 1

Type following command in terminal :

  sudo update-alternatives --config java

It will ask you for:

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

  Selection      Path                                            Priority   Status

    0           /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   1061      auto mode

    1           /usr/lib/jvm/java-6-openjdk-amd64/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:

I enter 2 as I want to use java 1.7.0_21