#!/bin/bash
path="/usr/lib/jvm"
mkdir -p ${path}

echo "enter java tar.gz url (get links at https://jdk.java.net/java-se-ri/7)"
read url

[ "${url}" == "" ] && echo "java url empty!" && exit 1

curl -L ${url} > /tmp/java.tar.gz

tar xfz /tmp/java.tar.gz -C ${path}

for java_path in `ls -d ${path}/*`;
  do
    for app in java javac javadoc javap;
      do
        update-alternatives --install /usr/bin/${app} ${app} ${java_path}/bin/${app} 1
      done
  done