Java

Java is a popular, class-based, object-oriented programming language designed for platform independence and enterprise software development.

Installation

Option 1: OpenJDK 21 LTS (Recommended)

OpenJDK 21 is the current Long-Term Support (LTS) release of Java.

sudo apt update
sudo apt install -y openjdk-21-jdk

Option 2: Default OpenJDK

To install the default OpenJDK version packaged by Ubuntu:

sudo apt update
sudo apt install -y default-jdk

Managing Java Versions

If multiple JDKs are installed, switch between them using:

sudo update-alternatives --config java
sudo update-alternatives --config javac

Verification

Check the installed Java compiler and runtime versions:

java -version
javac -version

Writing and Compiling Code

Create a file named Main.java:

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

Compile

javac Main.java

Execute

java Main

Official Resources

• Official Website