Thread.stop() - deprecated

When your thread handles interrupts correctly, it should be possible to instantly terminate it with use of ExecutorService interface. According to Oracle documentation, ExecutorService.shutdownNow() method, attempts to stop all actively executing tasks without waiting for their termination. There are however no guarantees beyond best-effort attempts to stop them. Here is some sample code:

class MyThread implements Runnable{
    @Override
    public void run() {
        for (int i = 1; i < 10000000; i++)
            try {
            System.out.println(i + " ThreadID: " + Thread.currentThread().getId());
            if (Thread.interrupted()) 
                    throw new InterruptedException();
            } catch (InterruptedException e) {
                return;
        }   
    }
}

ExecutorService executor = Executors.newFixedThreadPool(3);
            executor.submit(new MyThread());
            executor.submit(new MyThread());
            executor.submit(new MyThread());
            executor.shutdownNow();

Without termination each thread should print message to console 10000000 times. executor.shutdownNow() method instantly stops all three threads.

You asked:

My question is if theres no way to stop a thread in Java then how to stop a thread?

The Answer: In Java there's no clean, quick or reliable way to stop a thread.

Thread termination is not so straight forward. A running thread, often called by many writers as a light-weight process, has its own stack and is the master of its own destiny (well daemons are). It may own files and sockets. It may hold locks. Abrupt Termination is not always easy: Unpredictable consequences may arise if the thread is in the middle of writing to a file and is killed before it can finish writing. Or what about the monitor locks held by the thread when it is shot in the head?

Instead, Threads rely on a cooperative mechanism called Interruption. This means that Threads could only signal other threads to stop, not force them to stop.

To stop threads in Java, we rely on a co-operative mechanism called Interruption. The concept is very simple. To stop a thread, all we can do is deliver it a signal, aka interrupt it, requesting that the thread stops itself at the next available opportunity. That’s all. There is no telling what the receiver thread might do with the signal: it may not even bother to check the signal; or even worse ignore it.

Source: https://codeahoy.com/java/How-To-Stop-Threads-Safely/