java 几种常见的定时器
今天闲着没事就总结了一下在java中常用的几种定时器。
主要有3种java.util.Timer, ScheduledExecutorService和quartz
一.Timer
举个简单例子。每隔5秒自动刷新。
- Timer timerFresh = new Timer();
- timerFresh.schedule(new TimerTask() {
- public void run() {
- Display.getDefault().syncExec(new Runnable() {
- public void run() {
- setInputValue();//这里写你的方法,就可以了。
- }
- });
- }
- }, 5000, 5000);
二.ScheduledExecutorService
ScheduledExecutorService
schedule(Runnablecommand, long delay, TimeUnitunit) : ScheduledFuture
schedule(Callable<V> callable, long delay, TimeUnitunit) : ScheduledFuture
scheduleAtFixedRate(Runnablecomand, long initDelay, long period, TimeUnitunit) : ScheduledFuture
scheduleWithFixedDelay(Runnablecommand, long initDelay, long delay, TimeUnitunit) :
ScheduledFuturejava.util.concurrent.Executors是ScheduledExecutorService的工厂类,通过Executors,你可以创建你所需要的ScheduledExecutorService。JDK 1.5之后有了ScheduledExecutorService,不建议你再使用java.util.Timer,因为它无论功能性能都不如ScheduledExecutorService。
ScheduledExecutorService
ScheduledTaskSubmitter
ScheduleFuture<Object> future = scheduler.schedule(task, 1, TimeUnit.SECONDS);
// 等待到任务被执行完毕返回结果
// 如果任务执行出错,这里会抛ExecutionException
future.get();
//取消调度任务
future.cancel();
ScheduledFuturejava.util.concurrent.Executors是ScheduledExecutorService的工厂类,通过Executors,你可以创建你所需要的ScheduledExecutorService。JDK 1.5之后有了ScheduledExecutorService,不建议你再使用java.util.Timer,因为它无论功能性能都不如ScheduledExecutorService。
比如这篇文章讲的很好。
在Timer和ScheduledExecutorService间决择
http://sunnylocus.javaeye.com/blog/530969
三.quartz
这个目前考虑的比较全面用的比较多。
- /*
- * Copyright 2005 OpenSymphony
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy
- * of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
- *
- */
- package org.quartz.examples.example4;
- import java.util.Date;
- import org.apache.commons.logging.Log;
- import org.apache.commons.logging.LogFactory;
- import org.quartz.JobDetail;
- import org.quartz.Scheduler;
- import org.quartz.SchedulerFactory;
- import org.quartz.SchedulerMetaData;
- import org.quartz.SimpleTrigger;
- import org.quartz.TriggerUtils;
- import org.quartz.impl.StdSchedulerFactory;
- /**
- * This Example will demonstrate how job parameters can be
- * passed into jobs and how state can be maintained
- *
- * @author Bill Kratzer
- */
- public class JobStateExample {
- public void run() throws Exception {
- Log log = LogFactory.getLog(JobStateExample.class);
- log.info("------- Initializing -------------------");
- // First we must get a reference to a scheduler
- SchedulerFactory sf = new StdSchedulerFactory();
- Scheduler sched = sf.getScheduler();
- log.info("------- Initialization Complete --------");
- log.info("------- Scheduling Jobs ----------------");
- // get a "nice round" time a few seconds in the future....
- long ts = TriggerUtils.getNextGivenSecondDate(null, 10).getTime();
- // job1 will only run 5 times, every 10 seconds
- JobDetail job1 = new JobDetail("job1", "group1", ColorJob.class);
- SimpleTrigger trigger1 = new SimpleTrigger("trigger1", "group1", "job1", "group1",
- new Date(ts), null, 4, 10000);
- // pass initialization parameters into the job
- job1.getJobDataMap().put(ColorJob.FAVORITE_COLOR, "Green");
- job1.getJobDataMap().put(ColorJob.EXECUTION_COUNT, 1);
- // schedule the job to run
- Date scheduleTime1 = sched.scheduleJob(job1, trigger1);
- log.info(job1.getFullName() +
- " will run at: " + scheduleTime1 +
- " and repeat: " + trigger1.getRepeatCount() +
- " times, every " + trigger1.getRepeatInterval() / 1000 + " seconds");
- // job2 will also run 5 times, every 10 seconds
- JobDetail job2 = new JobDetail("job2", "group1", ColorJob.class);
- SimpleTrigger trigger2 = new SimpleTrigger("trigger2", "group1", "job2", "group1",
- new Date(ts + 1000), null, 4, 10000);
- // pass initialization parameters into the job
- // this job has a different favorite color!
- job2.getJobDataMap().put(ColorJob.FAVORITE_COLOR, "Red");
- job2.getJobDataMap().put(ColorJob.EXECUTION_COUNT, 1);
- // schedule the job to run
- Date scheduleTime2 = sched.scheduleJob(job2, trigger2);
- log.info(job2.getFullName() +
- " will run at: " + scheduleTime2 +
- " and repeat: " + trigger2.getRepeatCount() +
- " times, every " + trigger2.getRepeatInterval() / 1000 + " seconds");
- log.info("------- Starting Scheduler ----------------");
- // All of the jobs have been added to the scheduler, but none of the jobs
- // will run until the scheduler has been started
- sched.start();
- log.info("------- Started Scheduler -----------------");
- log.info("------- Waiting 60 seconds... -------------");
- try {
- // wait five minutes to show jobs
- Thread.sleep(60L * 1000L);
- // executing...
- } catch (Exception e) {
- }
- log.info("------- Shutting Down ---------------------");
- sched.shutdown(true);
- log.info("------- Shutdown Complete -----------------");
- SchedulerMetaData metaData = sched.getMetaData();
- log.info("Executed " + metaData.numJobsExecuted() + " jobs.");
- }
- public static void main(String[] args) throws Exception {
- JobStateExample example = new JobStateExample();
- example.run();
- }
- }
需要源码的可以去这里下载 http://dl.dbank.com/c0a4wn14yl