CentOS 7.6安装jdk1.8.0

1、查看JDK软件包列表：

yum -y list java*

2、安装jdk1.8.0的所有文件：

yum -y install java-1.8.0-openjdk*

3、查看JDK是否安装成功：

java -version
[centos@kafka3 zookeeper-3.4.14]$ java -version
openjdk version "1.8.0_252"
OpenJDK Runtime Environment (build 1.8.0_252-b09)
OpenJDK 64-Bit Server VM (build 25.252-b09, mixed mode)

4、配置环境变量

JDK默认安装路径/usr/lib/jvm

[centos@kafka3 lib]$ cd /usr/lib/jvm
[centos@kafka3 jvm]$ ls
java
java-1.8.0
java-1.8.0-openjdk
java-1.8.0-openjdk-1.8.0.252.b09-2.el7_8.x86_64
java-openjdk
jre
jre-1.8.0
jre-1.8.0-openjdk
jre-1.8.0-openjdk-1.8.0.252.b09-2.el7_8.x86_64
jre-openjdk　

在/etc/profile文件最后一行添加如下代码：

# set java environment  
JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.252.b09-2.el7_8.x86_64
PATH=$PATH:$JAVA_HOME/bin  
CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar  
export JAVA_HOME  CLASSPATH  PATH

ESC 退出:wq保存profile文件

执行如下命令使变量生效：

source /etc/profile