Install Oracle Java from source

Background

I am using jhipster to generate spring boot project. It compile but it does not work well. The first thing is that some function is not compatible. Also, hibernate insert data twice that cause ConstraintViolationException. I had post a Issue.

It works well on Java 8, so I have to install one more version. However, I cannot install via PPA. It is because webupd8 has DISCONTINUED since we need to login to download. So, I have to download java manually. I can use update-alternatives to switch version.

Install

1. Download 1.8 jdk from Oracle. Register an account and then download. It is better to download jdk-8u211-linux-x64.tar.gz.
2. scp upload the file to server.
3. unzip the file at server with tar xzvf filename.
4. Move the folder into /usr/lib/jvm/ (The location my java 11 was installed).
5. Then use update-alternatives with commands.

   update-alternatives --install /usr/bin/java java /usr/lib/jvm/java-8-oracle-amd64/bin/java 100
   update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/java-8-oracle-amd64/bin/javac 100
   update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/java-8-oracle-amd64/bin/jar 100
   

6. Update command to specify version.

   update-alternatives --config java
   update-alternatives --config javac
   update-alternatives --config jar
   

7. Check java version if it works.
8. write $JAVA_HOME to specify location. I write it to /usr/lib/jvm/default-java and link to directory with ln.

Then when you switch version, you just change the link to specify version. Inspired by Rahul.