https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
进到目录/usr/local/software解压上传的jdk文件：tar -zxvf jdk-8u201-linux-x64.tar.gz
重命名：mv jdk1.8.0_201 jdk8
vim /etc/profile
加入
export JAVA_HOME=/usr/local/software/jdk8
export PATH=
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JAVA_HOME/bin:
JAVAHOME/bin:PATHi
export CLASSPATH=.:
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JAVA_HOME/lib/dt.jar:
JAVAHOME/lib/dt.jar:JAVA_HOME/lib/tools.jar
export JAVA_HOME PATH CLASSPATH
使用 source /etc/profile 让配置立刻生效
