Runnable vs. Thread in Java

Runnable vs. Thread in Java: A Concise Guide

For Java/Spring Boot developers, choosing between implementing Runnable and extending Thread for multithreading boils down to flexibility and best practices. Extending Thread directly limits inheritance (you can only extend one class), while implementing Runnable allows for multiple interfaces and better code organization.

Recommended Approach: Implement Runnable

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        // Your thread logic here
        System.out.println("Runnable thread running");
    }
}

// Usage:
Thread thread = new Thread(new MyRunnable());
thread.start();

Why Runnable is preferred:

• Flexibility: Allows multiple inheritance of interfaces. A class can implement Runnable and other interfaces.
• Composition over Inheritance: Promotes better code design by favoring composition over inheritance.
• Testability: Easier to unit test your runnable logic independently of the Thread class.

Using Thread directly (Less preferred):

public class MyThread extends Thread {
    @Override
    public void run() {
        // Your thread logic here
        System.out.println("Thread subclass running");
    }
}

// Usage:
MyThread thread = new MyThread();
thread.start();

In Spring Boot, consider using @Async annotation for simpler asynchronous operations, avoiding manual thread management. This handles thread pool management for you.

In summary: Favor Runnable for its flexibility, maintainability, and adherence to good object-oriented principles. Only extend Thread if absolutely necessary and understand the implications. For Spring Boot, leverage the @Async annotation wherever possible.