set_java_ver

#!/bin/bash
###########################################################
#
# script to download and set default java version
#
# (c) 2021 nimmis <kjell.havneskold@gmail.com>
#
###########################################################

function get_cpu_arch_for_java () {
  cpu_arch_line=$(lscpu | grep Architecture)
  case "$cpu_arch_line" in
    *x86_64*)
      echo "x64"
      ;;
    *armv7*)
      echo "arm"
      ;;
    *armv8*) # unconfirmed
      echo "aarch64"
      ;;
    *)
      echo "Unknown processor architecture. Please file a bug report."
      ;;
  esac
}

function set_java_17 () {
  if ! [ -d /usr/lib/jvm/jdk-17* ]; then
    CPU_ARCH=$(get_cpu_arch_for_java)
    echo "Downloading JDK 1.17 $CPU_ARCH"
    curl -L "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.2%2B8/OpenJDK17U-jdk_${CPU_ARCH}_linux_hotspot_17.0.2_8.tar.gz"  | tar xz -C /usr/lib/jvm
  fi

  echo "set java version to 17"
  rm -f /usr/lib/jvm/default-jvm
  ln -s /usr/lib/jvm/jdk-17* /usr/lib/jvm/default-jvm

}


function set_java_16 () {
  if ! [ -d /usr/lib/jvm/jdk-16* ]; then
    CPU_ARCH=$(get_cpu_arch_for_java)
    echo "Downloading JDK 1.16 $CPU_ARCH"
    curl -L "https://github.com/adoptium/temurin16-binaries/releases/download/jdk-16.0.2%2B7/OpenJDK16U-jdk_${CPU_ARCH}_linux_hotspot_16.0.2_7.tar.gz"  | tar xz -C /usr/lib/jvm
  fi

  echo "set java version to 16"
  rm -f /usr/lib/jvm/default-jvm 
  ln -s /usr/lib/jvm/jdk-16* /usr/lib/jvm/default-jvm

}

function set_java_11 () {
  if ! [ -d /usr/lib/jvm/jdk-11* ]; then
    CPU_ARCH=$(get_cpu_arch_for_java)
    echo "Downloading JDK 1.11 $CPU_ARCH"
    curl -L "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.14.1%2B1/OpenJDK11U-jdk_${CPU_ARCH}_linux_hotspot_11.0.14.1_1.tar.gz"  | tar xz -C /usr/lib/jvm
  fi

  echo "set java version to 11"
  rm -f /usr/lib/jvm/default-jvm 
  ln -s /usr/lib/jvm/jdk-11* /usr/lib/jvm/default-jvm

}

function set_java_8 () {
  if ! [ -d /usr/lib/jvm/jdk8* ]; then
    CPU_ARCH=$(get_cpu_arch_for_java)
    echo "Downloading JDK 1.8 $CPU_ARCH"
    curl -L "https://github.com/adoptium/temurin8-binaries/releases/download/jdk8u322-b06/OpenJDK8U-jdk_${CPU_ARCH}_linux_hotspot_8u322b06.tar.gz"  | tar xz -C /usr/lib/jvm
  fi

  echo "set java version to 8"
  rm -f /usr/lib/jvm/default-jvm
  ln -s /usr/lib/jvm/jdk8* /usr/lib/jvm/default-jvm

}
case "$1" in
  17)
    set_java_17
    ;;

  16)
    set_java_16
    ;;

  11)
    set_java_11
    ;;
  8)
    set_java_8
    ;;

  *)
    echo "set_java_ver <version>"
    echo "set the java version for the container"
    echo 
    echo "Available versions are 8, 11, 16 and 17"
    exit 1
  ;;
esac

exit 0