1.檢視CentOS自帶JDK是否已安裝
[root@wugenqiang ~]# yum list installed |grep java
若有自帶安裝的JDK,應如下操作進行解除安裝CentOS系統自帶Java環境
[root@wugenqiang ~]# java -version
java version "1.7.0_181"
OpenJDK Runtime Environment (rhel-2.6.14.8.el6_9-x86_64 u181-b00)
OpenJDK 64-Bit Server VM (build 24.181-b00, mixed mode)
[root@wugenqiang ~]# yum -y remove java-1.7.0-openjdk*
[root@wugenqiang ~]# yum -y remove tzdata-java.noarch
[root@wugenqiang ~]# java --version
-bash: /usr/bin/java: No such file or directory
2.檢視yum庫中的Java安裝包
[root@wugenqiang ~]# yum -y list java*
以yum庫中java-1.8.0為例, "*"表示将java-1.8.0的所有相關Java程式都安裝上
[root@wugenqiang ~]# yum -y install java-1.8.0-openjdk*
3.檢視剛安裝的Java版本資訊。
輸入:"java -version" 可檢視Java版本
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiI0gTMx81dsQWZ4lmZf1GLlpXazVmcvwFciV2dsQXYtJ3bm9CX9s2RkBnVHFmb1clWvB3MaVnRtp1XlBXe0xCMy81dvRWYoNHLwEzX5xCMx8FesU2cfdGLwMzX0xiRGZkRGZ0Xy9GbvNGLpZTY1EmMZVDUSFTU4VFRR9Fd4VGdsYTMfVmepNHLrJXYtJXZ0F2dvwVZnFWbp1zczV2YvJHctM3cv1Ce-cmbw5iM5IzNxEWZ0U2YxQjMxU2YxYzXxQDMxQDMxMzLcJTMxIDMy8CXn9Gbi9CXzV2Zh1WavwVbvNmLvR3YxUjLyM3Lc9CX6MHc0RHaiojIsJye.png)
輸入:"javac" 可檢視Java的編譯器指令用法