Core Java提供对多线程程序的完全控制.您可以开发一个多线程程序,可以根据您的要求完全暂停,恢复或停止.您可以在线程对象上使用各种静态方法来控制它们的行为.下表列出了这些方法 :
Sr.No. | 方法&说明 |
---|---|
1 | public void suspend() 此方法将线程置于挂起状态,并可使用resume()方法恢复. |
2 | public void stop( ) 此方法完全停止线程. |
3 | public void resume() 此方法恢复使用suspend()方法挂起的线程. |
4 | public void wait() 导致当前线程等到另一个线程调用notify(). |
5 | public void notify() 唤醒正在此对象监视器上等待的单个线程. |
请注意最新的版本Java的sions已经弃用了suspend(),resume()和stop()方法,所以你需要使用可用的替代方法.
class RunnableDemo implements Runnable { public Thread t; private String threadName; boolean suspended = false; RunnableDemo(String name) { threadName = name; System.out.println("Creating " + threadName ); } public void run() { System.out.println("Running " + threadName ); try { for(int i = 10; i > 0; i--) { System.out.println("Thread: " + threadName + ", " + i); // Let the thread sleep for a while. Thread.sleep(300); synchronized(this) { while(suspended) { wait(); } } } } catch (InterruptedException e) { System.out.println("Thread " + threadName + " interrupted."); } System.out.println("Thread " + threadName + " exiting."); } public void start () { System.out.println("Starting " + threadName ); if (t == null) { t = new Thread (this, threadName); t.start (); } } void suspend() { suspended = true; } synchronized void resume() { suspended = false; notify(); } } public class TestThread { public static void main(String args[]) { RunnableDemo R1 = new RunnableDemo("Thread-1"); R1.start(); RunnableDemo R2 = new RunnableDemo("Thread-2"); R2.start(); try { Thread.sleep(1000); R1.suspend(); System.out.println("Suspending First Thread"); Thread.sleep(1000); R1.resume(); System.out.println("Resuming First Thread"); R2.suspend(); System.out.println("Suspending thread Two"); Thread.sleep(1000); R2.resume(); System.out.println("Resuming thread Two"); } catch (InterruptedException e) { System.out.println("Main thread Interrupted"); } try { System.out.println("Waiting for threads to finish."); R1.t.join(); R2.t.join(); } catch (InterruptedException e) { System.out.println("Main thread Interrupted"); } System.out.println("Main thread exiting."); } }
上述程序产生以下输出 :
Creating Thread-1 Starting Thread-1 Creating Thread-2 Starting Thread-2 Running Thread-1 Thread: Thread-1, 10 Running Thread-2 Thread: Thread-2, 10 Thread: Thread-1, 9 Thread: Thread-2, 9 Thread: Thread-1, 8 Thread: Thread-2, 8 Thread: Thread-1, 7 Thread: Thread-2, 7 Suspending First Thread Thread: Thread-2, 6 Thread: Thread-2, 5 Thread: Thread-2, 4 Resuming First Thread Suspending thread Two Thread: Thread-1, 6 Thread: Thread-1, 5 Thread: Thread-1, 4 Thread: Thread-1, 3 Resuming thread Two Thread: Thread-2, 3 Waiting for threads to finish. Thread: Thread-1, 2 Thread: Thread-2, 2 Thread: Thread-1, 1 Thread: Thread-2, 1 Thread Thread-1 exiting. Thread Thread-2 exiting. Main thread exiting.