Java is one of the most widely used programming languages, powering applications across various platforms, including desktop, web, mobile, and embedded systems. To develop Java applications, you need the Java Development Kit (JDK), which includes essential tools like the compiler (javac), debugger, and the Java Runtime Environment (JRE).

In this guide, we’ll walk you through installing OpenJDK on Ubuntu 20.04 LTS, setting up environment variables, and verifying the installation.

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Prerequisites

✔ Ubuntu 20.04 LTS (installed and updated)
✔ Terminal access (with sudo privileges)
✔ Stable internet connection

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Step 1: Update System Packages

Before installing any new software, it’s best practice to update your system’s package repository:

sudo apt update

Then, upgrade existing packages:

sudo apt upgrade -y

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Step 2: Install OpenJDK

Ubuntu’s default repositories include multiple OpenJDK versions (11, 13, 14). To install OpenJDK 14, run:

sudo apt install openjdk-14-jdk -y

Alternative versions:

• JDK 11 (LTS) → sudo apt install openjdk-11-jdk
• JDK 13 → sudo apt install openjdk-13-jdk

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Step 3: Verify Installation

Check the installed Java version:

java --version

Expected output:

openjdk 14.0.2 2020-07-14
OpenJDK Runtime Environment (build 14.0.2+12-Ubuntu-120.04)
OpenJDK 64-Bit Server VM (build 14.0.2+12-Ubuntu-120.04, mixed mode, sharing)

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Step 4: Configure Default Java Version (If Multiple JDKs Installed)

If you have multiple JDK versions, set the default using:

sudo update-alternatives --config java

Select the desired version by entering its selection number.

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Step 5: Set JAVA_HOME Environment Variable

Many Java applications require the JAVA_HOME variable.

Find Java Installation Path

Run:

sudo update-alternatives --config java

Copy the path (e.g., /usr/lib/jvm/java-14-openjdk-amd64/bin/java).

Edit Environment File

Open /etc/environment in a text editor:

sudo nano /etc/environment

Add the following line (replace the path with yours):

JAVA_HOME="/usr/lib/jvm/java-14-openjdk-amd64"

Save (Ctrl + X, then Y, then Enter).

Apply Changes

Reload the environment file:

source /etc/environment

Verify:

echo $JAVA_HOME

Should display the JDK path.

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Step 6: Tast Java Compilation

Create a simple Java file:

nano HelloWorld.java

Paste:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, Ubuntu 20.04!");
    }
}

Compile & run:

javac HelloWorld.java
java HelloWorld

Expected outputs::

Hello, Ubuntu 20.04!

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Final Thoughts

You’ve successfully installed OpenJDK 14 on Ubuntu 20.04 LTS and configured the JAVA_HOME environment variable. Now, you’re ready to develop and run Java applications seamlessly.

For more IT tutorials, stay tuned to our blog!

Tags:
Java, JDK, Ubuntu 20.04, OpenJDK, Programming, Linux

Hashtags:

#Java #Ubuntu #OpenJDK #Programming #Linux #TechGuide

Rakesh Bhardwaj

Rakesh Bhardwaj is a seasoned editor and designer with over 15 years of experience in the creative industry. He specializes in crafting visually compelling and professionally polished content, blending precision with creativity. Whether refining written work or designing impactful visuals, Rakesh brings a deep understanding of layout, typography, and narrative flow to every project he undertakes.

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