如何使后台活动在应用程序停止时停止

public class MainActivity extends AppCompatActivity {
    private MyBackgroundTask backgroundTask;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        backgroundTask = new MyBackgroundTask();
        backgroundTask.start();
    }

    @Override
    protected void onStop() {
        super.onStop();
        backgroundTask.stop();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        backgroundTask.releaseResources();
    }

    private class MyBackgroundTask {
        private boolean running;

        public void start() {
            running = true;
            // 启动后台活动的逻辑代码
        }

        public void stop() {
            running = false;
            // 停止后台活动的逻辑代码
        }

        public void releaseResources() {
            // 释放后台活动的资源的逻辑代码
        }
    }
}