ubuntu 下jdk安装配置

sudo mkdir /usr/lib/jvm

sudo tar zxvf jdk-8u71-linux-x64.tar.gz  -C /usr/lib/jvm

sudo gedit  /etc/profile

    export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_71 
    export CLASSPATH=".:$JAVA_HOME/lib:$CLASSPATH"  
    export PATH="$JAVA_HOME/bin:$PATH"  

    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_71/bin/java 300  
    sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_71/bin/javac 300  
    sudo update-alternatives --config java  

java -version