卸载centos自带openjdk

1 查看jdk版本

[root@localhost ~]# java -version
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (build 1.8.0_242-b08)
OpenJDK 64-Bit Server VM (build 25.242-b08, mixed mode)

2 查看自带的jdk

[root@localhost ~]# rpm -qa|grep java
javapackages-tools-3.4.1-11.el7.noarch
java-1.8.0-openjdk-1.8.0.242.b08-1.el7.x86_64
python-javapackages-3.4.1-11.el7.noarch
tzdata-java-2019c-1.el7.noarch
java-1.8.0-openjdk-headless-1.8.0.242.b08-1.el7.x86_64

3 卸载openjdk

rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.242.b08-1.el7.x86_64 tzdata-java-2019c-1.el7.noarch python-javapackages-3.4.1-11.el7.noarch java-1.8.0-openjdk-1.8.0.242.b08-1.el7.x86_64 javapackages-tools-3.4.1-11.el7.noarch

.noarch的也可以不用删除

4 上传下载的jdk,并解压

[root@localhost ~]# mkdir -p /usr/java
[root@localhost ~]# cd /usr/java/
[root@localhost ~]# tar -zxvf jdk-8u202-linux-x64.tar.gz
[root@localhost ~]# cp -r jdk1.8.0_202/ /usr/java/

5 设置环境变量

[root@localhost home]# vim /etc/profile

根据自己的目录设置环境变量,替换目录后追加到/etc/profile文件尾部

export JAVA_HOME=/usr/java/jdk1.8.0_202
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}

6 刷新环境变量

[root@localhost ~]# source /etc/profile
[root@localhost usr]# java -version
java version "1.8.0_202"
Java(TM) SE Runtime Environment (build 1.8.0_202-b08)
Java HotSpot(TM) 64-Bit Server VM (build 25.202-b08, mixed mode)