查找:
echo $JAVA_HOME
java -verion
ps -ef|grep java
安装:
tar -zxvf jdk-8u231-linux-x64.tar.gz -C /export/java
vi /etc/profile
export JAVA_HOME=/usr/java/jdk1.8.0_211
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib:$CLASSPATH
export JAVA_PATH=${JAVA_HOME}/bin:${JRE_HOME}/bin
export PATH=$PATH:${JAVA_PATH}
