Update 12.04 (precise) to Java 7 (OpenJDK)

Q: By default, Ubuntu 12.04 comes with OpenJDK 6, which is by now quite old and some applications require at least Java 7. How can I update an Ubuntu 12.04 installation to Java 7?

The Ubuntu 12.04 repositories contain both version 6 and 7 of the JDK, but by default only version 6 is installed.

To update, it is best to use the Synaptic package manager – if you don’t have it, install it with sudo apt-get install synaptic.

• Note: Ensure that Java 7 packages are selected before deselecting any Java 6 packages – else Synaptic will deselect anything that depends on Java (including any Java applications)!
• Search for icedtea and select icedtea-7-plugin for installation. This may select some Java 7 dependencies.
• Now search for openjdk and deselect openjdk-6 as well as openjdk-6-jre. This may deselect some further packages.
• If you had openjdk-6-jdk installed, make sure it is now selected for removal and openjdk-7-jdk is selected for installation. (You can skip this step if openjdk-6-jdk is not selected, meaning it was never installed.)
• Click Apply and review your package selections:
  
  • default-jre packages are metapackages which are safe to remove in this process.
  • icedtea-7-jre-cacao is a dummy package, therefore it it OK to remove icaedtea-6-cacao without installing a replacement.
    
  • For any other Java/IcedTea 6 package that is removed, you should be installing the Java 7 equivalent.
  • Packets to be selected for removal should include the following:
    
    • default-jre
    • default-jre-headless
    • icedtea-6-jre-cacao
    • icedtea-6-jre-jamvm
    • openjdk-6-jre openjdk-6-jre-headless
    • openjdk-6-jre-lib
  • Instead, the following should be installed:
    
    • icedtea-7-jre-jamvm
    • icedtea-7-plugin
    • openjdk-7-jre
    • openjdk-7-headless
    • openjdk-7-lib
  • If any packages are missing, go back and select them manually. When everything is OK, install.

From a console, run java -version. If you have JDK installed, also run javac -version. Both should now report version 1.7.0.