目录解压
cd /usr/java/jdk1.8.0
tar -xvf jdk1.8.0.tar
//修改环境变量
vi etc/profile
export JAVA_HOME=/usr/java/jdk1.8.0
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
:q!
source etc/profile
java -version