Java环境彻底卸载与安装方法教程(史上最全!)

java -version

dirname $(dirname $(readlink -f $(which java)))

rpm -qa | grep 'java\|jdk\|gcj\|jre'

jdk-1.8-1.8.0_381-9.x86_64

rpm -e --nodeps jdk-1.8-1.8.0_381-9.x86_64

rpm -ql jdk-1.8-1.8.0_381-9.x86_64

yum list installed | grep 'java\|jdk\|gcj\|jre'

jdk-1.8.x86_64      2000:1.8.0_381-9      installed

yum -y remove jdk-1.8.x86_64

rm -rf /usr/local/jdk1.8.0_381/

export JAVA_HOME=/usr/local/jdk1.8.0_381
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib

source /etc/profile

rpm -ivh jdk-8u381-linux-x64.rpm

java -version
which java

wget https://download.oracle.com/otn/java/jdk/8u311-b11/4d5417147a92418ea8b615e228bb6935/jdk-8u311-linux-x64.rpm

yum list installed | grep 'java\|jdk\|gcj\|jre'

yum search java | grep -i --color jdk

java-1.8.0-openjdk.x86_64 : OpenJDK 8 Runtime Environment
java-1.8.0-openjdk-devel.x86_64 : OpenJDK 8 Development Environment

yum install -y java-1.8.0-openjdk-devel.x86_64

java -version
which java

tar -zxvf jdk-8u381-linux-x64.tar.gz

mv jdk1.8.0_381/ /usr/local/
cd /usr/local/jdk1.8.0_381
ll

vim /etc/profile

export JAVA_HOME=/usr/local/jdk1.8.0_381
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib

source /etc/profile

java -version
which java

Java 安装流程
├── 卸载旧版本
│   ├── rpm 卸载
│   ├── yum 卸载
│   └── tar.gz 手动删除
├── 安装新版本
│   ├── RPM 安装
│   ├── YUM 安装
│   └── tar.gz 安装
└── 配置环境变量
    ├── /etc/profile
    ├── source /etc/profile
    └── 验证 java -version