switch between java versions

.bash_profile

# Simple way ============================
function setjdk() {
  if [ $# -ne 0 ]; then
    if [ -n "${JAVA_HOME+x}" ]; then
        removeFromPath "$JAVA_HOME/bin"
    fi

    export JAVA_HOME=`/usr/libexec/java_home -v $@`
    export PATH=$JAVA_HOME/bin:$PATH
  fi
}

function removeFromPath() {
  export PATH=$(echo $PATH | sed -E -e "s;:$1;;" -e "s;$1:?;;")
}


# Simple way 2 ============================
function setjdk() {
  if [ $# -ne 0 ]; then
    switchjdk $@
  else
    echo "Choose from the following Java versions:"
    choosejdk
    echo "Please enter the correct full version number:"
    read jdkPick
    switchjdk $jdkPick
  fi
}

function switchjdk() {
  removeFromPath '/System/Library/Frameworks/JavaVM.framework/Home/bin'
  if [ -n "${JAVA_HOME+x}" ]; then
    removeFromPath $JAVA_HOME
  fi
  export JAVA_HOME=$(/usr/libexec/java_home -v $@)
  export PATH=$JAVA_HOME/bin:$PATH
}

function choosejdk() {
  allVersions=$(/usr/libexec/java_home -V)
}

function removeFromPath() {
  export PATH=$(echo $PATH | sed -E -e "s;:$1;;" -e "s;$1:?;;")
}

# For zsh Function to switch JDK versions
function setjdk() {
  echo "Select the java version you wish to switch to from the following:"
  echo
  allVersions=()
  count=0

  while IFS= read -r line; do
    if [[ ! "$line" == M* ]] && [[ ! "$line" == /* ]] && [[ ! -z "$line" ]]; then
      allVersions+=($line)
      ((count++))
      echo '['"$count"']'${allVersions[$count]}
    fi
  done < <(/usr/libexec/java_home -V 2>&1)

  echo "Please chose a value from the options above:"
  read selectedOption </dev/tty

  if [ "$count" -ge "$selectedOption" ] && [ "$selectedOption" -ge '0' ]; then
    removeFromPath '/System/Library/Frameworks/JavaVM.framework/Home/bin'
    removeFromPath "$JAVA_HOME/bin"
    stringArray=(${allVersions[$selectedOption]})
    export JAVA_HOME="${stringArray[@]: -1}"
    export PATH="$JAVA_HOME"/bin:$PATH
    echo "JAVA_HOME is set to be ${JAVA_HOME}"
  else
    echo "Invalid option, JAVA_HOME was not set"
  fi
}

function removeFromPath() {
  export PATH=$(echo $PATH | sed -E -e "s;:$1;;" -e "s;$1:?;;")
}



# For bash Function to switch JDK versions
function setjdk() {
    echo "Select the java version you wish to switch to from the following:" 
    echo 
    options=()
    count=-1

        while IFS= read -r line
        do
            if [[ ! "$line" == M* ]] && [[ ! "$line" == /* ]] && [[ ! -z "$line" ]]; then
                options+=("$line")
                ((count++))
                echo '['"$count"']'${options["$count"]}
            fi
        done < <(/usr/libexec/java_home -V 2>&1)

    echo 
    read -p "Please chose a value from the options above: " selectedOption </dev/tty
    
    if [ "$count" -ge "$selectedOption" ] && [ "$selectedOption" -ge '0' ]; then
        removeFromPath '/System/Library/Frameworks/JavaVM.framework/Home/bin'
        removeFromPath "$JAVA_HOME/bin"
        stringArray=(${options["$selectedOption"]})
        export JAVA_HOME="${stringArray[@]: -1}"
        export PATH="$JAVA_HOME"/bin:$PATH
        echo "JAVA_HOME is set to be ${JAVA_HOME}"
    else
        echo "Invalid option, JAVA_HOME was not set"
    fi
}

function removeFromPath() {
  export PATH=$(echo $PATH | sed -E -e "s;:$1;;" -e "s;$1:?;;")
 }

from developer.atlassian.com