Script to switch between different Java VMs on a Debian based system

jvm

#!/usr/bin/env bash
#
# Switch between different installed Java VMs in a Debian based system
#

available=( $(update-alternatives --list java) )
if [ -n "${1}" ]; then
  case "${1}" in
    /*bin/java)
      VM="${1}"
      ;;
    *)
      for i in "${available[@]}"; do
        if [[ "${i}" =~ ${1} ]]; then
          VM="${i}"
        fi
      done
      ;;
  esac
  if [ -n "${VM}" ]; then
    echo "Switching JVM to ${VM}"
    sudo update-alternatives --set java "${VM}"
  else
    echo "'${1}' didn't match any known jvms :("
    ${0}
  fi
else
  echo "There are ${#available[@]} installed JVM(s)..."
  for vm in "${available[@]}"; do
    echo "  ${vm}"
  done
  echo 
  echo "USAGE: ${0} <vm name>"
fi
echo "Current JVM is $(readlink /etc/alternatives/java)"