linux:安装JDK

#安装JDK
$ mkdir /usr/local/java
$ cp /root/syslog/jdk-6u31-linux-x64.bin  ./
$ ./jdk-6u31-linux-x64.bin
#配置环境变量
$ vi /etc/profile	
#set java enviroment
export JAVA_HOME=/usr/local/java/jdk1.6.0_31
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/jre/lib/rt.jar

$update-alternatives --install /usr/bin/java java /usr/local/java/jdk1.6.0_31/bin/java 60
$update-alternatives --config java


#系统会给予提示，选择使用哪个jdk

$ source /etc/profile
$ java -version