Step-by-Step Guide to Install Java on Linux Systems

Java Install on Linux, need detailed steps, step by step instruction

Installing Java on a Linux system can vary slightly depending on the distribution you are using (e.g., Ubuntu, CentOS, Fedora, etc.). Below are detailed step-by-step instructions for installing Java on two popular Linux distributions: Ubuntu (or Debian-based systems) and CentOS (or Red Hat-based systems).

Installing Java on Ubuntu/Debian

1. Update Package Index Open a terminal and update the package index to ensure you have the latest information on available packages.

   sudo apt update
   

2. Install Java You can install the default Java Runtime Environment (JRE) or the Java Development Kit (JDK). The JDK includes the JRE and development tools.

   • To install the default JDK:

     sudo apt install default-jdk
     

   • To install a specific version (e.g., OpenJDK 11):

     sudo apt install openjdk-11-jdk
     

3. Verify Installation After installation, verify that Java is installed correctly by checking the version:

   java -version
   

4. Set JAVA_HOME Environment Variable (Optional) If you need to set the JAVA_HOME environment variable, you can do so by adding it to your profile.

   • Open the profile file in a text editor (e.g., nano):

     nano ~/.bashrc
     

   • Add the following line at the end of the file (adjust the path if necessary):

     export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
     

   • Save the file and exit the editor (in nano, press CTRL + X, then Y, and Enter).

   • Load the new environment variable:

     source ~/.bashrc
     

5. Check JAVA_HOME To verify that JAVA_HOME is set correctly, run:

   echo $JAVA_HOME
   

Installing Java on CentOS/RHEL

1. Update Package Index Open a terminal and update the package index:

   sudo yum update
   

2. Install Java You can install the default JDK or a specific version.

   • To install the default JDK:

     sudo yum install java-1.8.0-openjdk-devel
     

   • To install OpenJDK 11:

     sudo yum install java-11-openjdk-devel
     

3. Verify Installation Check the installed version of Java:

   java -version
   

4. Set JAVA_HOME Environment Variable (Optional) If you need to set the JAVA_HOME environment variable, you can do so by adding it to your profile.

   • Open the profile file in a text editor:

     nano ~/.bash_profile
     

   • Add the following line at the end of the file (adjust the path if necessary):

     export JAVA_HOME=/usr/lib/jvm/java-11-openjdk
     

   • Save the file and exit the editor.

   • Load the new environment variable:

     source ~/.bash_profile
     

5. Check JAVA_HOME To verify that JAVA_HOME is set correctly, run:

   echo $JAVA_HOME
   

Conclusion

You have now successfully installed Java on your Linux system. You can start developing Java applications or run Java-based applications as needed. If you encounter any issues, make sure to check the installation logs or consult the documentation for your specific Linux distribution.