1) tar -xvf jdk-8u181-linux-x64.tar.gz
2) mv jdk1.8.0_181/ /usr/local/java
3)vim /etc/profile
4)
export JAVA_HOME=/usr/local/java
export CLASSPATH=$:CLASSPATH:$JAVA_HOME/lib/
export PATH=$PATH:$JAVA_HOME/bin
5)source /etc/profile
6）java -version
