CentOS 7 卸载 OpenJDK 安装 OracleJDK

1. 查看 JDK 安装版本

java -version
java version 1.7.0_51
OpenJDK Runtime Environment ( rhel-2.4.5.5.el7-x86_64 u51-b31)
OpenJDK 64-Bit Server VM (build 24.51-b03, mixed mode)

1. 查找 OpenJDK 安装包

rpm -qa | grep openjdk
java-1.7.0-openjdk-headless-1.7.0.51-2.4.5.5.el7.x86_64
java-1.7.0-openjdk-1.7.0.51-2.4.5.5.el7.x86_64

1. 卸载 OpenJDK 安装包

yum -y remove java-1.7.0-openjdk-headless.x86_64
yum -y remove java-1.7.0-openjdk.x86_64

1. 下载 Oracal JDK 1.8 安装包

https://download.oracle.com/otn/java/jdk/8u271-b09/61ae65e088624f5aaa0b1d2d801acb16/jdk-8u271-linux-x64.tar.gz?AuthParam=1604821028_917e41350e9f21dd34a92eb8fc26e861

1. 解压 Oracal JDK 1.8

tar -zvxf jdk-8u271-linux-x64.tar.gz

1. 配置环境变量

vim /etc/profile

在文件末尾添加如下内容

JAVA_HOME=/opt/java
PATH=$JAVA_HOME/bin:$PATH
CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export JAVA_HOME
export PATH
export CLASSPATH

刷新环境变量配置

source /etc/profile

1. 查看安装结果

java -version
java version "1.8.0_271"
Java(TM) SE Runtime Environment (build 1.8.0_271-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.271-b09, mixed mode)

Done