Java platform and JVM overview - Mini Project: Build & Apply

Java Platform and JVM Overview

📖 Scenario: You are learning how Java programs run on different computers using the Java platform and the Java Virtual Machine (JVM). This project will help you understand the basic setup and how Java code is executed step-by-step.

🎯 Goal: Build a simple Java program that shows the role of the Java platform and JVM by creating a class, setting a version variable, running a method, and printing the output.

📋 What You'll Learn

Create a Java class named JavaPlatformDemo

Add a String variable called javaVersion with value "Java SE 17"

Write a method runJVM() that returns the string "Running on JVM"

Print the javaVersion and the result of runJVM() in the main method

💡 Why This Matters

🌍 Real World

Understanding the Java platform and JVM basics helps you write programs that run anywhere Java is installed, making your code portable and reliable.

💼 Career

Many software jobs require knowledge of how Java programs execute on the JVM, which is essential for debugging, performance tuning, and cross-platform development.

1

Create the Java class and version variable

Create a public class called JavaPlatformDemo. Inside it, declare a String variable named javaVersion and set it to "Java SE 17".

Java

public class JavaPlatformDemo {
    // Declare javaVersion variable here
    // Your code here
}

Need a hint?

Remember to write public class JavaPlatformDemo and inside it String javaVersion = "Java SE 17";

2

Add the runJVM method

Inside the JavaPlatformDemo class, add a method named runJVM that returns a String. This method should return the text "Running on JVM".

Java

public class JavaPlatformDemo {
    String javaVersion = "Java SE 17";

    // Add runJVM method here
    // Your code here
}

Need a hint?

Define String runJVM() method that returns "Running on JVM".

3

Add the main method to run the program

Add a public static void main(String[] args) method inside JavaPlatformDemo. Inside it, create an object of JavaPlatformDemo named demo. Then call demo.runJVM() and store the result in a variable named jvmStatus.

Java

public class JavaPlatformDemo {
    String javaVersion = "Java SE 17";

    String runJVM() {
        return "Running on JVM";
    }

    // Add main method here
    // Your code here
}

Need a hint?

Write the main method, create demo object, and call runJVM().

4

Print the Java version and JVM status

In the main method, add two System.out.println statements. First, print the javaVersion variable from the demo object. Second, print the jvmStatus variable.

Java

public class JavaPlatformDemo {
    String javaVersion = "Java SE 17";

    String runJVM() {
        return "Running on JVM";
    }

    public static void main(String[] args) {
        JavaPlatformDemo demo = new JavaPlatformDemo();
        String jvmStatus = demo.runJVM();
        // Print javaVersion and jvmStatus here
        // Your code here
    }
}

Need a hint?

Use System.out.println(demo.javaVersion); and System.out.println(jvmStatus); to print the values.