export JAVA_HOME=/opt/JAVA/jdk1.8.0_191
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib/tools.jar:${JAVA_HOME}/lib/dt.jar:${JRE_HOME}/lib/rt.jar
export PATH=$PATH:${JAVA_HOME}/bin
原文：https://www.cnblogs.com/MimiSnowing/p/10416517.html