4.1.1 Thread Creation Explained

Thread creation in Java is a fundamental aspect of concurrent programming. Threads allow multiple tasks to run concurrently, improving the efficiency and responsiveness of applications. Understanding how to create and manage threads is crucial for developing robust and high-performance Java applications.

Key Concepts

1. Extending the Thread Class

One way to create a thread in Java is by extending the Thread class and overriding its run() method. The run() method contains the code that will be executed in the new thread.

Example

        class MyThread extends Thread {
            public void run() {
                System.out.println("Thread is running");
            }
        }
        
        public class Main {
            public static void main(String[] args) {
                MyThread thread = new MyThread();
                thread.start(); // Starts the thread
            }
        }
    

2. Implementing the Runnable Interface

Another common approach to creating a thread is by implementing the Runnable interface. This method is more flexible as it allows the class to extend other classes if needed. The Runnable interface requires the implementation of the run() method.

Example

        class MyRunnable implements Runnable {
            public void run() {
                System.out.println("Thread is running");
            }
        }
        
        public class Main {
            public static void main(String[] args) {
                MyRunnable runnable = new MyRunnable();
                Thread thread = new Thread(runnable);
                thread.start(); // Starts the thread
            }
        }
    

3. Using Lambda Expressions

With the introduction of lambda expressions in Java 8, creating threads has become more concise. Lambda expressions can be used to implement the Runnable interface inline, reducing boilerplate code.

Example

        public class Main {
            public static void main(String[] args) {
                Thread thread = new Thread(() -> {
                    System.out.println("Thread is running");
                });
                thread.start(); // Starts the thread
            }
        }
    

Examples and Analogies

Think of a thread as a worker in a factory. Each worker (thread) can perform a specific task independently. By creating multiple workers (threads), you can increase the overall productivity of the factory (application). For example, one worker might be responsible for assembling products, while another handles packaging.

By mastering thread creation, you can design applications that efficiently utilize system resources, leading to better performance and responsiveness.