How to interrupt a running thread in Java?
A thread can send an interrupt by invoking interrupt on the Thread object for the thread to be interrupted. This means interruption of a thread is caused by any other thread calling the interrupt() method.
The Thread class provides three interrupt methods
- void interrupt() - Interrupts the thread.
- static boolean interrupted() - Tests whether the current thread has been interrupted.
- boolean isInterrupted() - Tests whether the thread has been interrupted.
Example
public class ThreadInterruptTest {
public static void main(String[] args) {
System.out.println("Thread main started");
final Task task = new Task();
final Thread thread = new Thread(task);
thread.start();
thread.interrupt(); // calling interrupt() method
System.out.println("Main Thread finished");
}
}
class Task implements Runnable {
@Override
public void run() {
for (int i = 0; i < 5; i++) {
System.out.println("[" + Thread.currentThread().getName() + "] Message " + i);
if(Thread.interrupted()) {
System.out.println("This thread was interruped by someone calling this Thread.interrupt()");
System.out.println("Cancelling task running in thread " + Thread.currentThread().getName());
System.out.println("After Thread.interrupted() call, JVM reset the interrupted value to: " + Thread.interrupted());
break;
}
}
}
}Output
Thread main started
Main Thread finished
[Thread-0] Message 0
This thread was interruped by someone calling this Thread.interrupt()
Cancelling task running in thread Thread-0
After Thread.interrupted() call, JVM reset the interrupted value to: false
Published on 10-Sep-2019 10:20:35
