Switching JVMs in Mountain Lion

README.md

Switching JVMs in Mountain Lion

Apple made it incredibly difficult to switch JVMs since Mountain Lion. This might make it slightly easier.

Installation

1. Download jvm.sh to ~/bin

2. Create an alias for jvm.sh to jvm in ~/.profile or ~/.zshrc or whatever

   alias jvm="source ~/bin/jvm.sh"

3. Start a new shell.

Usage

1. To see current JVM and list JVMs

   jvm

2. To unset JVM

   jvm -u

3. To switch JVM

   jvm /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home

jvm.sh

#!/bin/bash

listJavaHomes() {
  echo "Choose from:" >&2
  find /Library/Java -name "Home" -type d | grep -i java
  find /System/Library/Java/JavaVirtualMachines -name "Home" -type d | grep -i java
}

echo "Before: JAVA_HOME=${JAVA_HOME}" >&2
if [ "$1" = "" ]; then
  listJavaHomes
elif [ "$1" = "-u" ]; then
  unset JAVA_HOME
else
  export JAVA_HOME=$1
fi
echo "After : JAVA_HOME=${JAVA_HOME}" >&2