How to uninstall openjdk and install Oracle JDK under CentOS

Write it at the front

commonly Linux The system will bring its own JDK, nothing but Open JDk, What we usually use in development is Oracle JDK, So we need to write in Open JDK, And then install Oracle JDK

One 、 uninstall Open JDK

The next operation needs to be in root Under permission

1、 It is recommended to switch to root Account

#  Switch to root Account 
su -

2、 Query whether the system can install jdk

rpm -qa|grep java

3、 Uninstall installed jdk

#  reminder , The file name is for reference only , The details shall be subject to your own 
rpm -e --nodeps java-1.8.0-openjdk-1.8.0.161-2.b14.el7.x86_64
rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.161-2.b14.el7.x86_64

4、 Verify that there are jdk

rpm -qa|grep java
java -version

Two 、 install Oracle JDK

1. First download a Linux Version of JDK, Recommended download JDK8, Here is a quick download Mirror website , It's much better than the turtle speed on the official website , Suggest collection ！！！

2. First copy the installation package to Centos in , Recommended here Xftp, If you don't know how to use , See my other blog Portal

   

3. Then decompress jdk Compressed package

   #  Small Tips：0jdk Knock it out   Directly by tab It will be completed automatically ^_^
   tar -zxvf jdk-8u202-linux-x64.tar.gz
   

   

4. edit /etc/profile file , Configure environment variables

   Just put it at the end

   # Set Java Envieonment
   #  Just pay attention to JAVA_HOME Change your path to your own , You can copy the rest 
   export JAVA_HOME=/home/jsj/jdk1.8.0_202
   export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
   export PATH=$PATH:$JAVA_HOME/bin
   

   

5. take effect profile

   source /etc/profile
   java -version
   

   

Conclusion

It's not easy to create , If it helps you , Give me a free compliment ！！！