1. 查看CentOS自带JDK是否已安装
[root@test ~]# yum list installed |grep java
2. 若有自带安装的JDK，应如下操作进行卸载CentOS系统自带Java环境
[root@test ~]# 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@test ~]# yum -y remove java-1.7.0-openjdk*
[root@test ~]# yum -y remove tzdata-java.noarch
[root@test ~]# java --version
-bash: /usr/bin/java: No such file or directory
3. 查看yum库中的Java安装包
[root@test ~]# yum -y list java*
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: centos.ustc.edu.cn
* extras: centos.ustc.edu.cn
* updates: centos.ustc.edu.cn
base | 3.7 kB 00:00
extras | 3.4 kB 00:00
updates | 3.4 kB 00:00
Available Packages
java-1.5.0-gcj.x86_64 1.5.0.0-29.1.el6 base
java-1.5.0-gcj-devel.x86_64 1.5.0.0-29.1.el6 base
java-1.5.0-gcj-javadoc.x86_64 1.5.0.0-29.1.el6 base
java-1.5.0-gcj-src.x86_64 1.5.0.0-29.1.el6 base
java-1.6.0-openjdk.x86_64 1:1.6.0.40-1.13.12.6.el6_8 updates
java-1.6.0-openjdk-demo.x86_64 1:1.6.0.40-1.13.12.6.el6_8 updates
java-1.6.0-openjdk-devel.x86_64 1:1.6.0.40-1.13.12.6.el6_8 updates
java-1.6.0-openjdk-javadoc.x86_64 1:1.6.0.40-1.13.12.6.el6_8 updates
java-1.6.0-openjdk-src.x86_64 1:1.6.0.40-1.13.12.6.el6_8 updates
java-1.7.0-openjdk.x86_64 1:1.7.0.111-2.6.7.2.el6_8 updates
java-1.7.0-openjdk-demo.x86_64 1:1.7.0.111-2.6.7.2.el6_8 updates
java-1.7.0-openjdk-devel.x86_64 1:1.7.0.111-2.6.7.2.el6_8 updates
java-1.7.0-openjdk-javadoc.noarch 1:1.7.0.111-2.6.7.2.el6_8 updates
java-1.7.0-openjdk-src.x86_64 1:1.7.0.111-2.6.7.2.el6_8 updates
java-1.8.0-openjdk.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-debug.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-demo.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-demo-debug.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-devel.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-devel-debug.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-headless.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-headless-debug.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-javadoc.noarch 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-javadoc-debug.noarch 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-src.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java-1.8.0-openjdk-src-debug.x86_64 1:1.8.0.101-3.b13.el6_8 updates
java_cup.x86_64 1:0.10k-5.el6 base
java_cup-javadoc.x86_64 1:0.10k-5.el6 base
java_cup-manual.x86_64 1:0.10k-5.el6 base
javacc.x86_64 4.1-0.5.el6 base
javacc-demo.x86_64 4.1-0.5.el6 base
javacc-manual.x86_64 4.1-0.5.el6 base
javassist.noarch 3.9.0-6.el6 base
javassist-javadoc.noarch 3.9.0-6.el6 base
4. 安装
** 以yum库中java-1.8.0为例, "*"表示将java-1.8.0的所有相关Java程序都安装上**
[root@test ~]# yum -y install java-1.8.0-openjdk*
- 查看刚安装的Java版本信息。 输入："java -version" 可查看Java版本 输入："javac" 可查看Java的编译器命令用法