Get it from the App Store.
In XCode's Preferences > Downloads you can install command line tools.
$ java -version | |
java version "1.6.0_25" | |
Java(TM) SE Runtime Environment (build 1.6.0_25-b06) | |
Java HotSpot(TM) 64-Bit Server VM (build 20.0-b11, mixed mode) | |
$ alias -p | grep clhsdb | |
alias clhsdb='java -classpath .:$JAVA_HOME/lib/sa-jdi.jar sun.jvm.hotspot.CLHSDB' | |
$ clhsdb | |
hsdb> help | |
Available commands: | |
assert true | false |