shell脚本安装JDK

这个脚本我一直在用但不是我写的，可以在centos和ubuntu下使用，其它系统没测试，使用时要先去官网下好jdk,并改好脚本里的文件名和安装目录

#!/bin/bash
chmod u+x jdk-6u33-linux-x64.bin
installPath=/usr/java
if [ ! -d /usr/java ];
 then
     mkdir /usr/java
 fi
./jdk-6u33-linux-x64.bin -D  /usr/java
cp  -R jdk1.6.0_33/ /usr/java/jdk1.6.0_33/
touch environment
echo "PATH=\"$PATH:/usr/java/jdk1.6.0_33/bin\"" >> environment
echo "JAVA_HOME=/usr/java/jdk1.6.0_33" >> environment
echo "CLASSPATH=.:%JAVA_HOME%/lib/dt.jar:%JAVA_HOME%/lib/tools.jar" >> environment
rm -rf /etc/environment
cp environment /etc
source /etc/environment
update-alternatives --install /usr/bin/java java /usr/java/jdk1.6.0_33/bin/java 300
update-alternatives --install /usr/bin/javac javac /usr/java/jdk1.6.0_33/bin/javac 300
update-alternatives --config java