Check installed java version and upgrade if new release is available

update-java.sh

#! /bin/bash

# function to install latest java
function download() {
  echo "Downloading java $1"
  # here you have to write curl or wget command to download java 
  # version to be downloaded will be available in $1
}

# get version of JAVA installed
INSTALLED_JAVA_VERSION=`java -version 2>&1 | awk 'NR==1{ gsub(/"/,""); print $3 }'`
echo "Installed version $INSTALLED_JAVA_VERSION"

# check the latest version of JAVA available
LATEST_JAVA_VERSION=`curl -s http://javadl-esd-secure.oracle.com/update/baseline.version | head -n 1`
echo "Latest version $LATEST_JAVA_VERSION"

if [ "$(printf "$LATEST_JAVA_VERSION\n$INSTALLED_JAVA_VERSION" | sort -V | head -n1)" == "$INSTALLED_JAVA_VERSION" ] && [ "$LATEST_JAVA_VERSION" != "$INSTALLED_JAVA_VERSION" ]; then
  echo "Upgrading to $LATEST_JAVA_VERSION"
  download $LATEST_JAVA_VERSION
else
  echo "Everything up-todate"
fi