linux安装jdk

1.下载Linux环境下的jdk1.8
https://www.oracle.com/java/technologies/downloads/#java8

2.JDK压缩包解压
tar -zxvf jdk-8u181-linux-x64.tar.gz -C /usr/local

3.环境变量导入
[root@localhost local]# vim /etc/profile

export JAVA_HOME=/usr/local/jdk1.8.0_181  #jdk安装目录
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}

##环境变量生效
[root@localhost local]# source /etc/profile

##确认安装是否成功
[root@localhost local]# javac
[root@localhost local]# java -version