Install JAVA on Ubuntu 18.04 LTS manually

How to install JAVA on Ubuntu 18.04 LTS manually.

Prerequisites:-

Make sure the non root user is under sudo group.

Install the tar.gz file of java 8 or any version you want

(I did it with java1.8.0_221)

Steps to Perform:

Step1: unzip the java….tar.gz file accordingly to any folder

Step2: Check if /usr/lib/ has a java or jvm or any other repository of jdk home if not present then create one.

$ sudo mkdir /usr/lib/java

(java is home of jdk dir)

Step3: move the unzip jdk to the following newly created ‘java’ directory.

$ sudo mv /sourcefile /usr/lib/java

Change sourcefile with the unzip jdk path and paste it to /usr/lib/java

Step4: check if java or javac executable file is created under /usr/bin/

If not present then run the following commad if present then something is wrong either is not completely installed earlier

For JAVA:

$ sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/java/jdk(version/folder) /bin/java" 1

For JAVAC

$ sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/java/jdk(version/folder) /bin/javac" 1

Step5: export the JAVA_HOME

Open Terminal run the following command:

$ export JAVA_HOME=/usr/lib/java/jdk(folder/version)

Done !!

Check if java installed and JAVA_HOME is set by following command

1.     $ java -version

Output :

Java version. “1.8.0_211“

………..

…..xx..x.x..x

2.     $ echo $JAVA_HOME

Output  /usr/lib/java/jdk