Moving from JDK 1.7 to JDK 1.8 on Ubuntu

Question

I am on UBUNTU. JDK version currently installed is:

java version \"1.7.0_51\"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Se         


        

Answer 1

Most of the answers for this question can not helped me in 2020.

This notification from download site of Oracle may be the reason:

Important Oracle JDK License Update

The Oracle JDK License has changed for releases starting April 16, 2019.

I try to google a little bit and those tutorials below helped me a lot.

1. Remove completely the previous version of JVM installed on your PC.

   sudo update-alternatives --remove-all java
   sudo update-alternatives --remove-all javac
   sudo update-alternatives --remove-all javaws
   
   # /usr/lib/jvm/jdk1.7.0 is the path you installed the previous version of JVM on your PC
   sudo rm -rf /usr/lib/jvm/jdk1.7.0 
   

   Check to see whether java is uninstalled or not

   java -version
   

2. Install Java 8 JDK.

   • Download Java 8 from Oracle's website. The version being used is 1.8.0_251. Pay attention to this value, you may need it to edit commands in this answer when Java 8 is upgraded to another version.
   • Extract the compressed file to the place where you want to install.

   cd /usr/lib/jvm
   sudo tar xzf ~/Downloads/jdk-8u251-linux-x64.tar.gz
   

   • Edit environment file

   sudo gedit /etc/environment
   

   • Edit the PATH's value by appending the string below to the current value

   :/usr/lib/jvm/jdk1.8.0_251/bin:/usr/lib/jvm/jdk1.8.0_251/jre/bin
   

   • Append those strings to the environment file

   J2SDKDIR="/usr/lib/jvm/jdk1.8.0_251"
   J2REDIR="/usr/lib/jvm/jdk1.8.0_251/jre"
   JAVA_HOME="/usr/lib/jvm/jdk1.8.0_251"
   

   • Complete the installation by running commands below

   sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.8.0_251/bin/java" 0
   sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.8.0_251/bin/javac" 0
   sudo update-alternatives --set java /usr/lib/jvm/jdk1.8.0_251/bin/java
   sudo update-alternatives --set javac /usr/lib/jvm/jdk1.8.0_251/bin/javac
   
   update-alternatives --list java
   update-alternatives --list javac