Return a value for `$JAVA_HOME` or execute command using this variable.
List JVMs based on a specific version
java_home --version 1.5+
List JVMs based on a specific [arch]itecture
java_home --arch i386
List JVMs based on a specific tasks (defaults to `CommandLine`)
java_home --datamodel Applets|WebStart|BundledApp|JNI|CommandLine
List JVMs in a XML format
java_home --xml
Display help
java_home --help