Introduction

Multithreading in Java is the solution to give you better performance and speed while developing applications. In today’s world, speed and performance matters a lot, especially in software applications. From a web page loading through a mobile app running, users want everything instantly; they do not want any delay in their work.

This is the reason Java is used with multithreading as it makes a program do all its functions simultaneously. This makes the application faster, more efficient, and more responsive.

What is multithreading?

Running multiple threads simultaneously within a single program is called multithreading. A thread is like a small part of a program that can run a task separately.

In simple words, a thread is like a lightweight process: when you start a Java program, it begins with one thread, which is known as the main thread. When you need to do other work but still keep the main thread running, you can create other threads.

For example, if you are playing a game, your character can move while listening to music in the background while at the same time, the game checks for other actions. All three actions are performed using threads.

Why should We Use Multithreading?

Some real benefits of using multithreading in Java are:

• Faster operation: Multiple tasks are running simultaneously.
• Improved User Experience: UI apps do not freeze since the background tasks run in external threads.
• High CPU Utilisation: Free CPU time can be used by threads.

Benefits of Multithreading in Java

This is best for your background tasks, like downloading files or any other data processing, without disturbing the remaining part of your application.
Therefore, if you want to start a multithreaded program, there are two ways in which you can do it in Java itself:

1. Extend the Thread class

This is by creating your new thread by creating a subclass of Thread and redefining its run () method.

class MyFirstThread extends Thread {
    public void run() {
        System. out. println("Thread is running first time");
    }
}
public class Example {
    public static void main(String[] args) {
        MyFirstThread c = new MyFirstThread();
        c.start();
    }
}

2. Implementing the Runnable interface

By implementing the Runnable interface and passing it to a Thread object, you can create another type of thread.

class MyFirstRunnable implements Runnable {
    public void run() {
        System. out. println("Runnable thread is running first time");
    }
}
public class Example {
    public static void main(String[] args) {
        Thread thr1 = new Thread(new MyFirstRunnable());
        thr.start();
    }
}

Key Concepts in Multithreading

Some simple concepts need to be known when working with threads:

1. Thread Life Cycle:
• New: Created thread
• Runnable: Ready to run and waits for the CPU.
• Running: The Thread is currently executing.
• Blocked/Waiting: The Thread has been paused for some time.
• Terminated: The Thread has performed its work.

2. Thread Methods
• start (): Starts the thread.
• run (): Having the code that the thread will execute.
• sleep (ms): Suspend the thread for some given time.
• join (): Waits for one thread to finish before continuing.
• isAlive (): Check to see if the thread is still running.

3. Synchronisation
As two or more threads share the same data, they may make changes to it at the same time, and thus a problem will occur. To avoid this problem, there is synchronisation in Java, which ensures that only one thread can use the shared resource at a time.

Example:

 synchronized void printData() {
   //Only a single thread can access this block at a time
}

A Simple Use Case of Multithreading

Suppose you are downloading a file and want to display a loading bar at the same time; without multithreading, your program would be doing one thing at a time: performing the download or displaying the progress bar. By using threads, you will show the user that the application is smooth and responsive.

Tips for Using Multithreading

Here are practical and effective tips for using multithreading in Java:

• Do not create as many threads as possible because, in the end, it will slow down.
• Synchronise your threads carefully to avoid data errors.
• Use thread pools (ExecutorService) when you have lots of threads.
• Test your multithreaded code in a good manner because if you cannot do this, finding bugs can be really complicated.

Conclusion

Multithreading in Java ensures that your applications can perform multitasking. It allows applications to improve in terms of performance, responsiveness, and, most importantly, system resource utilisation. Learning how to create and manage threads will help you build faster and smarter Java applications.

I suggest you to check out the Java tutorial section on TPoint Tech Website, which helps you to learn Java easily, in clear way with simple explanations and practical approaches.