安装jdk

1.下载：https://download.oracle.com/otn/java/jdk/8u211-b12/478a62b7d4e34b78b671c754eaaf38ab/jdk-8u211-linux-x64.tar.gz?AuthParam=1557370208_e4a17ca2450ed8ea3be227406b6dbc59

2.解压到目录：tar xf jdk-8u211-linux-x64.tar.gz -C /usr/local/elk/java/

3.配置环境变量 vim /etc/profile

export JAVA_HOME=/usr/local/elk/java
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export  PATH=${JAVA_HOME}/bin:$PATH

4.生效配置：source /etc/profile

5.验证版本：java -version