Switch Java Versions on Debian/Ubuntu

javaSwitch.sh

#!/bin/sh

clear

f_o6 () {
  export JAVA_HOME=/usr/lib/jvm/java-6-openjdk-amd64;
  sudo update-alternatives --set java /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java;
}

f_s6 () {
  export JAVA_HOME=/usr/lib/jvm/java-6-sunjdk-amd64;
  sudo update-alternatives --set java /usr/lib/jvm/java-6-sunjdk-amd64/jre/bin/java;
}

f_o7 () {
  export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64;
  sudo update-alternatives --set java /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java;
}

f_o8 () {
  export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64;
  sudo update-alternatives --set java /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java;
}

echo 'To apply to the current shell, be sure to run as:'
echo '. javaSwitch.sh'
echo

echo 'Choose Java version:  (6) OpenJDK 6, (6s) SunJDK 6, (7) OpenJDK 7, or (8) OpenJDK 8'
read choice

case $choice in
  6) f_o6 ;;
  6s) f_s6;;
  7) f_o7;;
  8) f_o8;;
  *) echo "\"$choice\" is not valid"
esac

#sudo update-alternatives --get-selections | grep -i java
env | grep JAVA_HOME
echo
java -version

Simple but fantastic.

Could be easily modified to support non-amd64 platforms but doesn't work as-is.