Install Oracle Java JDK in Ubuntu 20.04 LTS

Install Java Jdk

Java is the most popular programming language. To install Java on Ubuntu we have to follow the following steps:

Step 1 : Download Oracle Java JDK

First of all Download Java JDK on your system from official oracle website.

Download Oracle Java Jdk :  
https://www.oracle.com/java/technologies/javase-downloads.html

Step 2: Check Java version

Check if java is already installed on your system or not.

$ java -version

Step 3: Install Java using debian file

Use the following command to install the downloaded debian file.

$ sudo dpkg -i jdk-version.deb

Step 4 : Set up Environment variable

For setting up environment varible first of all navigate to this folder. /user/lib/jvm.

$ ls /user/lib/jvm

Now update java alternatives

$ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-16.0.1/bin/java 1

Then, update java compiler alternatives

$ sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk-16.0.1/bin/javac 1

Now if you check the version of Java and Java Compiler :

$ java --version
$ javac --version

For JAVA_HOME

Now for setting up JAVA_HOME type the following commands on terminal.

 $ sudo update-alternatives --config java 
 $ source /etc/environment 
 $ echo $JAVA_HOME

Go through this video for complete instruction for Java JDK installation with JAVA_HOME