sudo vi /etc/profile
#set java environment
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_121
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib:CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
source /etc/profile
sudo gedit /etc/environment
## 添加以下内容
PATH=¨" :$JAVA_HOME/bin"
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_121
export CLASSPATH=..:$JAVA_HOME/lib:$JAVA_HOME/jre/lib
source /etc/environment
原文:https://www.cnblogs.com/ilyar1015/p/14679330.html