【环境配置】CentOS7环境安装JDK

清除自带openJDK，安装Oracle官网JDK

1 查看Java版本

java -version

2 查看安装包并删除

rpm -qa | grep jdk
rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.181-7.b13.el7.x86_64
rpm -e --nodeps java-1.7.0-openjdk-1.7.0.191-2.6.15.5.el7.x86_64
rpm -e --nodeps java-1.8.0-openjdk-1.8.0.181-7.b13.el7.x86_64
rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.191-2.6.15.5.el7.x86_64

3 下载JDK安装包并解压缩

tar -zxvf jdk-11.0.3_linux-x64_bin.tar.gz
rm -rf jdk-11.0.3_linux-x64_bin.tar.gz

4 修改环境变量

# vim /etc/profile
JAVA_HOME=/root/software/java/jdk-11.0.3
JRE_HOME=/root/software/java/jdk-11.0.3/jre
CLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib
PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin
export JAVA_HOME JRE_HOME CLASS_PATH PATH

vim保存指令--[shift+zz]/[:wq]

生效配置文件
# source /etc/profile

5 测试

# javac
# java -version