下载jdk-8u71-linux-x64.tar.gz创建jvm文件夹（/usr/lib/jvm）sudo mkdir /usr/lib/jvm
创建jvm文件夹（/usr/lib/jvm）sudo tar zxvf jdk-8u71-linux-x64.tar.gz -C /usr/lib/jvm
设置环境变量（全局）sudo gedit /etc/PRofile
打开profile文件输入
exportjava_HOME=/usr/lib/jvm/jdk1.8.0_71
export CLASSPATH=".:$JAVA_HOME/lib:$CLASSPATH"export PATH="$JAVA_HOME/bin:$PATH"
设置系统默认JDKsudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_71/bin/java300sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_71/bin/javac300sudo update-alternatives --config java
验证JDKjava -version