Install Oracle JDK on Oracle Linux

I could't find a reference to this in the JDK Install instructions so I thought I'd make a note of it here.

I installed the latest Oracle JDK on Oracle Linux using the RPM downloaded from here, but when I checked the version number I was still getting OpenJDK.
# rpm -ivh jdk-7u21-linux-x64.rpm
# java -version
java version "1.7.0_19"
OpenJDK Runtime Environment (rhel-
OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)

The solution is to use the RedHat "alternatives" utility.

1) Register the newly installed Oracle JDK with "alternatives"

# alternatives --install /usr/bin/java java /usr/java/default/bin/java 2

2) Set the new JDK to be the default

# alternatives --config java

Choose the option that represents the Java version you require.