Resolving version conflict between java and javac on Ubuntu

ubuntu java javac openjdk unsupported-class-version
xralf picture xralf · May 14, 2012 · Viewed 15k times · Source

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 configured in my PATH to run Java:

$ javac -version
javac 1.7.0_147

$ java -version
java version "1.6.0_23"
OpenJDK Runtime Environment (IcedTea6 1.11pre) (6b23~pre11-0ubuntu1.11.10.2)
OpenJDK Client VM (build 20.0-b11, mixed mode, sharing)

How can I resolve this?

Answer

Ruju picture Ruju · May 28, 2013

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

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