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import java.util.Collections;public class Test {	public void test() {		SScheduleExecutor scheduledThreadpool = new SScheduleExecutor();		System.out.println("Main test:time stamp = "+System.currentTimeMillis()/1000);  /*显示以秒为单位*/		scheduledThreadpool.submit(new NormalWork(), 2000);   /*以毫秒为单位*/		scheduledThreadpool.submit(new LoopWork(), 3000, 6000);	}		private class LoopWork implements Runnable {		@Override		public void run() {			// TODO Auto-generated method stub			System.out.println("LoopWork,time stamp = "+System.currentTimeMillis()/1000);		}			}		private class NormalWork implements Runnable {		@Override		public void run() {			// TODO Auto-generated method stub			System.out.println("NormalWork,time stamp = "+System.currentTimeMillis()/1000);		}			}}

import java.util.concurrent.Delayed;import java.util.concurrent.TimeUnit;public abstract class DelayTask implements Delayed{	protected Runnable command = null;	protected long iniDelay = -1; /*in milliseconds*/		public DelayTask() {			}		public Runnable getTask() {		return command;	}		@Override	/*返回：	 * 负值：当前对象小于输入对象	 * zero：当前对象等于输入对象	 * 正值：当前对象大于输入对象*/	public int compareTo(Delayed o) {		// TODO Auto-generated method stub		long defference = iniDelay - o.getDelay(TimeUnit.MILLISECONDS);				return (defference < 0) ? -1 : (defference > 0) ? 1 : 0;	}}

public class DelayTaskFactory {	public DelayTask createDelayTask(Runnable command,long iniDelay) {		return new NormalDelayTask(command,iniDelay);	}		public DelayTask createDelayTask(Runnable command,long iniDelay,long period) {		return new LoopTask(command, iniDelay, period);	}}

import java.util.concurrent.TimeUnit;public class LoopTask extends DelayTask{	private long period = -1;	private long periodTimeStamp = -1;	private boolean isFirstRun = true;  /*第一次执行后置为false*/		public LoopTask(Runnable command,long iniDelay,long period) {		super();		this.command = command;		this.iniDelay = System.currentTimeMillis()+iniDelay;		this.period = period;	}		@Override	public long getDelay(TimeUnit unit) {		// TODO Auto-generated method stub		if( false == isFirstRun && -1 != period ) {			/*周期任务，非第一次执行，返回period*/			return periodTimeStamp-System.currentTimeMillis();		}		return iniDelay-System.currentTimeMillis();	}		private void setFirstRunFalse() { isFirstRun = false; };	private void setFirstRunTrue() { isFirstRun = true; }		public void resetTask() {		setFirstRunFalse();		periodTimeStamp = System.currentTimeMillis()+period;	}}

import java.util.concurrent.TimeUnit;public class NormalDelayTask extends DelayTask{		public NormalDelayTask(Runnable command,long iniDelay) {  /*暂时默认以毫秒为单位*/		super();  		this.command = command;		this.iniDelay = System.currentTimeMillis()+iniDelay;	}		@Override	public long getDelay(TimeUnit unit) {  /*暂时默认以毫秒为单位*/		// TODO Auto-generated method stub		return iniDelay-System.currentTimeMillis();	}}

public interface SExecutorService {	public void submit(Runnable r,long delay,long period);	public void submit(Runnable r,long delay);}

import java.util.concurrent.BlockingQueue;import java.util.concurrent.DelayQueue;import java.util.concurrent.Delayed;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class SScheduleExecutor implements SExecutorService{	/*内部保存一个线程池，用来产生consumer，线程池暂定无界；producer则是每次调用submit，SScheduleExecutor自己；	 * 内部保存一个DelayQueue*/	private ExecutorService threadpool = Executors.newCachedThreadPool();	private BlockingQueue
   
     delayQueue = new DelayQueue
    
     ();		private DelayTaskFactory taskFac = new DelayTaskFactory();	private WorkerThreadFactory threadFac = new WorkerThreadFactory();		private void addWorkerThread(DelayTask task) {		try {			delayQueue.put(task);			/*新创建一个工作线程，执行对DelayQueue的take操作*/			threadFac.createWorkerThread().start();		} catch (InterruptedException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}	}		@Override	public void submit(Runnable r,long delay,long period) {		// TODO Auto-generated method stub		DelayTask task = taskFac.createDelayTask(r, delay, period);		addWorkerThread(task);	}		@Override	public void submit(Runnable r, long delay) {		// TODO Auto-generated method stub		DelayTask task = taskFac.createDelayTask(r, delay);		addWorkerThread(task);	}		/*工作线程，每提交一个任务，分配一个工作线程来take此任务，工作线程从DelayQueue中取出任务后，再执行任务*/	private class WorkerThread extends Thread{				public WorkerThread() {					}				@Override		public void run() {			// TODO Auto-generated method stub			/*对DelayQueue执行take操作，获取成功后，将task的是否第一次执行置为false（先判断是否looptask），			 * 如果是looptask，需要将此task再put到DelayQueue，执行完这些操作后，给task分配一个线程执行。*/			DelayTask task = null;			do {				task = (DelayTask)delayQueue.poll();  /*返回值若为null，表示queue里面没有数据*/				if( null != task ) {					if( task instanceof LoopTask ) {						((LoopTask) task).resetTask();						addWorkerThread(task);					}										threadpool.execute(task.getTask());				}			}while(null == task);		}	}		private class WorkerThreadFactory {		public WorkerThread createWorkerThread() {			return new WorkerThread();		}	}}/*用DelayQueue模拟了一个ScheduledExecutorService。 * 要点： * 1、Delayed接口的两个方法的实现 * 2、每个DelayTask配置一个工作线程，用来将DelayTask从DelayQueue中取出，执行，或者重设后执行 * 3、LoopTask的处理，initDelay与period的区别处理 * 4、getDelay方法，返回的是动态值，其单位与入参的TimeUnit匹配，具体匹配方式在方法内部实现 *  * 思考： * 1、priorityQueue使用compareTo方法将DelayTask排序 * 2、DelayQueue使用getDelay方法，根据返回值让工作线程delay，直到超时时间到 * 3、如果将工作线程也交给线程池分配，是否可降低开销？ * 4、工作线程与DelayTask线程能否合并？*/
    
   

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