I am currently working on an application that has multiple different threads running. The threads are running loops and cannot be stopped using interrupts, because a clean up method has to run after the thread stops.
Because I don't want to implement the same code for all these thread classes, I created an abstract subclass of the Thread class. The new class provides the following new functionality to its subclasses:
- Automatically call start up method when started
- Automatically call a method in an endless loop
- A way to stop the thread
- Automatically call clean up method when stopped
The implemenation of this abstract class:
package com.javaeenotes;
public abstract class AbstractStoppableThread extends Thread {
private volatile boolean stopThread = false;
@Override
public final void run() {
startUp();
while (!stopThread) {
runInLoop();
}
cleanUp();
}
public void stopThread() {
stopThread = true;
}
protected void startUp() {
;
}
protected abstract void runInLoop();
protected void cleanUp() {
;
}
}
A subclass of this class has to provide the actual overriding implementations of the last three methods. A class that demonstrates the use of the abstract class is shown next:
package com.javaeenotes;
public class ExampleThread extends AbstractStoppableThread {
@Override
protected void startUp() {
System.out.println("Thread started!");
}
@Override
protected void runInLoop() {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
;
}
System.out.println("Running in a loop!");
}
@Override
protected void cleanUp() {
System.out.println("Cleaning up resources!");
}
public static void main(String[] args) {
ExampleThread exampleThread = new ExampleThread();
exampleThread.start();
try {
Thread.sleep(10000);
exampleThread.stopThread();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
When the example is class is run, the program will output the following:
Thread started!
Running in a loop!
Running in a loop!
Running in a loop!
Running in a loop!
Running in a loop!
Cleaning up resources!
Other interesting links about stopping threads:
