昭通市网站建设_网站建设公司_UX设计_seo优化

一、常用方法

• schedule

private static void schedule(ScheduledExecutorService service, final int sleepTime){ service.schedule(new Runnable() { @Override public void run() { long start = new Date().getTime(); System.out.println("schedule 开始执行时间 " + DateFormat.getTimeInstance().format(new Date())); try { Thread.sleep(sleepTime); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } long end = new Date().getTime(); System.out.println("schedule 执行花费时间= " + (end - start) / 1000+"s"); System.out.println("schedule 结束执行时间 " + DateFormat.getTimeInstance().format(new Date())); System.out.println(">>>>>>>>>>>>>>>>>>>"); } },5,TimeUnit.SECONDS); }

结论：只会执行一次，比较简单

• scheduleAtFixedRate

延迟固定时间频率执行任务

任务执行耗时3s,period间隔为5s

scheduleAtFixedRate(service, 3000); private static void scheduleAtFixedRate(ScheduledExecutorService service, final int sleepTime) { service.scheduleAtFixedRate(new Runnable() { public void run() { long start = new Date().getTime(); System.out.println("scheduleAtFixedRate 开始执行时间 " + DateFormat.getTimeInstance().format(new Date())); try { Thread.sleep(sleepTime); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } // long end = System.currentTimeMillis(); long end = new Date().getTime(); System.out.println("scheduleAtFixedRate 执行花费时间= " + (end - start) / 1000); System.out.println("scheduleAtFixedRate 结束执行时间 " + DateFormat.getTimeInstance().format(new Date())); System.out.println(">>>>>>>>>>>>>>>>>>>"); } }, 1000, 5000, TimeUnit.MILLISECONDS); }

场景一：任务执行耗时时长小于period间隔，任务执行完成后，会等到了延迟时间，再执行下一次任务，本次任务开始时间+延迟时间间隔=下次任务开始时间

场景二：任务执行耗时时长大于period间隔，任务执行耗时5秒，period间隔为3秒，本次任务完成后，下次任务启动会立即执行.

scheduleAtFixedRate(service, 5000); private static void scheduleAtFixedRate(ScheduledExecutorService service, final int sleepTime) { service.scheduleAtFixedRate(new Runnable() { public void run() { long start = new Date().getTime(); System.out.println("scheduleAtFixedRate 开始执行时间 " + DateFormat.getTimeInstance().format(new Date())); try { Thread.sleep(sleepTime); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } // long end = System.currentTimeMillis(); long end = new Date().getTime(); System.out.println("scheduleAtFixedRate 执行花费时间= " + (end - start) / 1000+"s"); System.out.println("scheduleAtFixedRate 结束执行时间 " + DateFormat.getTimeInstance().format(new Date())); System.out.println(">>>>>>>>>>>>>>>>>>>"); } }, 1000, 3000, TimeUnit.MILLISECONDS); }

• ​​​​​scheduleWithFixedDelay

scheduleWithFixedDelay(service, 2000); private static void scheduleWithFixedDelay(ScheduledExecutorService service, final int sleepTime) { service.scheduleWithFixedDelay(new Runnable() { public void run() { long start = new Date().getTime(); System.out.println("scheduleWithFixedDelay 开始执行时间:" + DateFormat.getTimeInstance().format(new Date())); try { Thread.sleep(sleepTime); } catch (InterruptedException e) { e.printStackTrace(); } long end = new Date().getTime(); System.out.println("scheduleWithFixedDelay执行花费时间=" + (end - start) / 1000 + "s"); System.out.println("scheduleWithFixedDelay执行完成时间：" + DateFormat.getTimeInstance().format(new Date())); System.out.println("======================================"); } }, 1000, 3000, TimeUnit.MILLISECONDS); }

场景一：任务执行耗时小于period间隔，任务执行耗时2秒，period间隔为3秒

结论：本次任务执行结束时间+period=下次任务开始时间

scheduleWithFixedDelay(service, 5000); private static void scheduleWithFixedDelay(ScheduledExecutorService service, final int sleepTime) { service.scheduleWithFixedDelay(new Runnable() { public void run() { long start = new Date().getTime(); System.out.println("scheduleWithFixedDelay 开始执行时间:" + DateFormat.getTimeInstance().format(new Date())); try { Thread.sleep(sleepTime); } catch (InterruptedException e) { e.printStackTrace(); } long end = new Date().getTime(); System.out.println("scheduleWithFixedDelay执行花费时间=" + (end - start) / 1000 + "s"); System.out.println("scheduleWithFixedDelay执行完成时间：" + DateFormat.getTimeInstance().format(new Date())); System.out.println("======================================"); } }, 1000, 3000, TimeUnit.MILLISECONDS); }

场景一：任务执行耗时大于period间隔，任务执行耗时5秒，period间隔为3秒

结论：本次任务执行结束时间+period=下次任务开始时间，delay是计算上一个任务执行结束的时间和本次任务开始时间的差值，此值和任务的执行时间就没有关系了