java debian install

java debian install:

#!/bin/bash
path="/usr/lib/jvm"

echo "enter java url:"
read url

[ "${url}" == "" ] && echo "java url empty!"; exit 1
gurl ${url} > /tmp/java.tar.gz

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

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