How to uninstall OpenJDK then to install JDK on CentOS7? The bellow is the process to uninstall OpenJDK then to install JDK on CentOS.

Here, I use JDK 1.8 as an example.

1. Check JDK version on CentOS

[[email protected] ~]# java -version
openjdk version "1.8.0_131"
OpenJDK Runtime Environment (build 1.8.0_131-b12)
OpenJDK 64-Bit Server VM (build 25.131-b12, mixed mode)

2. Use grep Linux command to query the installed JDK package.

[[email protected] ~]# rpm -qa|grep jdk
java-1.7.0-openjdk-1.7.0.141-2.6.10.5.el7.x86_64
copy-jdk-configs-2.2-3.el7.noarch
java-1.8.0-openjdk-headless-1.8.0.131-11.b12.el7.x86_64
java-1.8.0-openjdk-1.8.0.131-11.b12.el7.x86_64
java-1.7.0-openjdk-headless-1.7.0.141-2.6.10.5.el7.x86_64

3. Using rpm command to uninstall openJDK

[[email protected] ~]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.141-2.6.10.5.el7.x86_64 java-1.8.0-openjdk-headless-1.8.0.131-11.b12.el7.x86_64 java-1.8.0-openjdk-1.8.0.131-11.b12.el7.x86_64 java-1.7.0-openjdk-headless-1.7.0.141-2.6.10.5.el7.x86_64

4. Download the JDK1.8 installation package and install it

Download the Linux rpm installation package from the Oracle web. TheĀ JDK download address.

[[email protected] download]# rpm -ivh jdk-8u162-linux-x64.rpm 
In preparation... ######################################## [100%]
Upgrading/installing...
   1:jdk1.8-2000:1.8.0_162-fcs        ################################# [100%]
Unpacking JAR files...
	tools.jar...
	plugin.jar...
	javaws.jar...
	deploy.jar...
	rt.jar...
	jsse.jar...
	charsets.jar...
	localedata.jar...

5. View the installed JDK version

[[email protected] ~]# java -version
java version "1.8.0_162"
Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)

When you see the installed JDK version information, it means you have installed the JDK on CentOS.