Multithreading and Multitasking in Java

Example:

class Task1 extends Thread {
    public void run() {
        for (int i = 1; i <= 5; i++) {
            System.out.println("Task 1 - Count: " + i);
        }
    }
}

class Task2 extends Thread {
    public void run() {
        for (int i = 1; i <= 5; i++) {
            System.out.println("Task 2 - Count: " + i);
        }
    }
}

public class MultiThreadExample {
    public static void main(String[] args) {
        Task1 t1 = new Task1();
        Task2 t2 = new Task2();
        t1.start();
        t2.start();
    }
}
    

Output: Both threads run concurrently, displaying interleaved results.

Example:

Running a Java program while listening to music and downloading a file — all at the same time. Each task runs independently in separate processes handled by the OS.

Improve program performance by executing tasks concurrently.
Utilize system resources efficiently.
Enable simultaneous operations for smoother user experience.

Faster execution and responsiveness.
Better CPU utilization.
Efficient use of idle processor time.
Supports real-time, parallel operations.

Thread synchronization can be complex.
Debugging multithreaded code is harder.
Improper handling may lead to deadlocks.
Performance overhead if too many threads are created.

1. Create threads using Thread class or Runnable interface.
2. Start threads using start() method.
3. Use sleep(), join(), and synchronized for managing execution.
4. Monitor thread lifecycle and handle exceptions.
5. Terminate threads after task completion.

Use proper synchronization to prevent race conditions.
Keep thread tasks lightweight and independent.
Utilize thread pools for managing large numbers of threads.
Handle exceptions inside threads for stability.