Friday, 4 November 2016

How to install JAVA in Linux OS?

Hi,

In this article, I am going to share you how to install JAVA in Linux - ubuntu/CentOS in a step by step manner.

Things required before install JAVA in Linux OS:



1. Download the JAVA from Oracle.com website. 
       1.1 : Under Downloads  - Select Java for Developers  option under popular download menu.
       1.2 : Click on JDK download button.JDK Download Icon from Oracle.com

       1.3 : Navigates to JDK Download Page and select appropriate JDK file from the listed one.

   Note:
        1. Before downloading the file, we need to accept the license and select the file to download
        2. File Format is to select tar.gz 
     Ex : jdk-8u111-linux-x64.tar.gz

2. Once the file download in your system, Open the terminal to unzip the file, from here onwards we use Unix commands to install JAVA.

Note:
   -  Unix commands are case-sensitive which means CD and cd are both different. 

3. First, navigate to file location path in terminal
      Ex: consider my JAVA file is in download location
          > cd download
4. To Unzip the tar file
      Ex: 
         > tar -xvf  jdk-8u111-linux-x64.tar.gz
5.  Check whether java folder was there in /usr/lib/ folder, if java folder was not there then create the folder inside /usr/lib.
         5.1 : first navigate to /usr/lib path
                  > cd /usr/lib
         5.2 : Create a java folder using mkdir command
                 > mkdir java inside /usr/lib directory.
                -- If it throws permission error then run using sudo before mkdir command.
                > sudo mkdir java
         5.3 : Navigate to java folder and move the unzipped JDK file from Downloads to java folder.
                 java> sudo mv jdk-1.8.0_11/ /usr/lib/java
         5.4 : Navigate to /usr/lib/java/jdk1.8.0_11/bin/ directory and next run the following commands                    in the same path.
                 > sudo update-alternatives --install "/usr/bin/java" "java"                      "/usr/lib/java/JDK_VERSION/bin/java" 1
                 > sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/java/JDK_VERSION/bin/javac" 1
                 > sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/java/JDK_VERSION/bin/javaws" 1

        5.5 : Navigate to Home directory using the cd ~ command.

 6. Now we need to enter Java path in bashrc file
        > gedit ~/.bashrc
        
      6.1 : Enter the following path details
           # JAVA HOME path details
          export JAVA_HOME=/usr/lib/java/JDK_VERSION
          export PATH="$PATH:$JAVA_HOME/bin"   
      6.2 : Save and close the text editor file.
 /bashrc file contains all the environment path details and tells that JAVA path to run.

 7. Close the terminal and open the new terminal
       7.1 : For checking whether JAVA is installed correctly then type the following commands,
              >java
             > javac 
             >java -version  - Shows the version of JAVA installed in our machine.

NoteReplace JDK_VERSION to your installed version.

Please let your comments in the comments section and share to others if you feel really useful and worth.

Thanks and happy coding :)
Nuthan.M