1. 下载jdk(jdk-8u101-linux-x64.tar.gz):http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
2. 创建java目录: mkdir /usr/local/java, 并将jdk解压到此目录
3. 设置jdk环境变量:在/etc/profile文件最下面添加以下命令,对所有用户永久生效
export JAVA_HOME=/usr/local/java/jdk1.8.0_101
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH
4. 使用配置生效:source /etc/profile
5. java -version
参考文章: http://www.cnblogs.com/haore147/p/3633116.html