Switching Java Versions on Mac OS X

In order to make a newly-built version of java act as the default java version, copy the entire ./build/bsd-i586/j2sdk-image dir to /usr/local/java-1.7.0-internal and add a suffix with the date:

$ sudo mv build/bsd-i586/j2sdk-image /usr/local/java-1.7.0-internal-`date "+%Y_%m_%d"`

Link /usr/local/java-1.7.0 to the latest build:

$ cd /usr/local
$ sudo ln -s java-1.7.0-internal-`date "+%Y_%m_%d"` java-1.7.0

I encapsulated these functions in the script update-usr-local.sh:

#!/bin/sh
buildname=java-1.7.0-internal-`date "+%Y_%m_%d"`
sudo rm -rf /usr/local/$buildname
sudo mkdir /usr/local/$buildname
sudo cp -r build/bsd-i586/j2sdk-image/* /usr/local/$buildname
cd /usr/local
sudo rm -f java-1.7.0
sudo ln -s $buildname java-1.7.0

This results in a new JVM:

$ ls -l /usr/local
....
lrwxr-xr-x    1 root  wheel    38 Jan 31 20:58 java-1.7.0 -> java-1.7.0-internal-2009_01_31
drwxr-xr-x   15 root  wheel   510 Jan 31 21:37 java-1.7.0-internal-2009_01_31

$ /usr/local/java-1.7.0/bin/java -version
openjdk version "1.7.0-internal"
OpenJDK Runtime Environment (build 1.7.0-internal-stephen_2009_01_25_23_54-b00)
OpenJDK Server VM (build 14.0-b10, mixed mode)