任务调度
quartz框架
quartz框架实现了Spring的任务调度,用户可以随意的定义触发器调度时间表,并将触发器和任务进行映射。quartz通过调度器、触发器和任务实现任务调度。
Job:主要用来设计任务实现的逻辑,并且只有一个方法execute。
JobDetail:主要用来通过newInstance()方法创建Job实例,该角色主要通过一些静态信息来描述Job的名称等信息。
Triger:作为任务的触发器,有两个类:SimpleTriger和CronTriger。当只触发一次或者周期性触发选择SimpleTriger。当定时触发时可以选择CronTriger。
Calendar:作为时间点的集合。
Scheduler:任务调度容器,Scheduler中注册Triger和JobDetail,将Triger和JobDetail关联起来。
实现任务调度步骤:
1、创建任务,并设置名称和组名。2、创建触发器,并设置名称和组名。3、对触发器设置时间规则。4、定义任务调度容器,将触发器与任务加入容器,并这只关联。
SimpleTriger任务调度实例:
创建任务类
package scheduler; import org.quartz.Job; import org.quartz.JobDetail; import org.quartz.JobExecutionContext; import org.quartz.JobExecutionException; public class SimpleJob implements Job{ @Override public void execute(JobExecutionContext arg0) throws JobExecutionException { // TODO Auto-generated method stub System.out.println("定时任务调度================="); } }
将任务与触发器关联
/** * */ /** * @author Administrator * */ package scheduler; import java.util.Collection; import org.quartz.Job; import org.quartz.JobBuilder; import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.SchedulerFactory; import org.quartz.SimpleScheduleBuilder; import org.quartz.SimpleTrigger; import org.quartz.TriggerBuilder; import org.quartz.impl.StdSchedulerFactory; import sun.java2d.pipe.SpanShapeRenderer.Simple; public class SimpleTriggerRunner { public static void main(String[] args){ try{ JobDetail jobDetail = JobBuilder.newJob(SimpleJob.class).withIdentity("job_1", "group_1").build(); SimpleTrigger trigger = TriggerBuilder .newTrigger() .withIdentity("trigger_1","group_triger") .startNow() .withSchedule(SimpleScheduleBuilder .simpleSchedule() .withIntervalInSeconds(5) .repeatForever()) .build(); SchedulerFactory factory = new StdSchedulerFactory(); Scheduler scheduler = factory.getScheduler(); scheduler.scheduleJob(jobDetail, trigger); scheduler.start(); }catch(Exception e){ e.printStackTrace(); } } }
CronTriger实现任务调度实例:
import java.util.Collection; import org.quartz.Job; import org.quartz.JobBuilder; import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SchedulerException; import org.quartz.SchedulerFactory; import org.quartz.SimpleScheduleBuilder; import org.quartz.SimpleTrigger; import org.quartz.TriggerBuilder; import org.quartz.impl.StdSchedulerFactory; import sun.java2d.pipe.SpanShapeRenderer.Simple; public class SimpleTriggerRunner { public static void main(String[] args){ try{ JobDetail jobDetail = JobBuilder.newJob(SimpleJob.class).withIdentity("job_1", "group_1").build(); SimpleTrigger trigger = TriggerBuilder .newTrigger() .withIdentity("trigger_1","group_triger") .startNow() .withSchedule(SimpleScheduleBuilder .simpleSchedule() .withIntervalInSeconds(5) .repeatForever()) .build(); SchedulerFactory factory = new StdSchedulerFactory(); Scheduler scheduler = factory.getScheduler(); scheduler.scheduleJob(jobDetail, trigger); scheduler.start(); }catch(Exception e){ e.printStackTrace(); } } }
Spring中使用quartz
创建JobDetailBean
步骤:
1、创建JobDetail实例JobDetailBean。对JobDetailBean进行属性设置,jobClass:用来指定任务;beanName:设置任务的名称;JobDataAsMap为任务的JobDataMap提供值;applicationContextJobDataKey:为Job提供applicationContext。2、创建Trigger触发器,主要是通过SimpleTriggerBean、CronTriggerBean和CronTriggerFactoryBean进行创建,需要将任务实例配置其中。3、通过SchedulerFactoryBean类配置Scheduler,将Trigger加入Schedulerde的Trigger列表中。
实例:
定义任务类
package scheduler; import java.util.Map; import org.quartz.Job; import org.quartz.JobExecutionContext; import org.quartz.JobExecutionException; import org.springframework.stereotype.Component; import bean.User; @Component("myJob") public class MyJob{ public void myexecute() { // TODO Auto-generated method stub System.out.println("Spring开始任务调度========="); System.out.println("Spring结束任务调度=========="); } }
将任务加入触发器,并设置调度时间。将触发器加入调度。
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd" > <context:component-scan base-package="scheduler"/> <!-- jobDetail --> <bean id="jobnew" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean"> <property name="targetObject" ref="myJob"/> <property name="targetMethod" value="myexecute"/> <!--false表示等上一个任务执行完后再开启新的任务--> <property name="concurrent" value="false"/> </bean> <!-- Trigger--> <bean id="oceanStatusCronTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean"> <property name="jobDetail" ref="jobnew"/> <property name="cronExpression" value="0 */2 * * * ?"/> </bean> <!--Scheduler --> <bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean"> <property name="triggers"> <list> <ref bean="oceanStatusCronTrigger"/> </list> </property> </bean> </beans>
Spring中使用Timer
Timer
当使用调度比较频繁时,可以考虑使用Timer,并不适合固定时间点例如每周周一上午八点的调度策略。但是对于长时间执行的任务来说,该调度会严重影响性能,因为每一个Timer是在同一个线程,Timer中的有多个TimerTask,执行时间过长容易引起积压。
TmierTask
TimerTask相当于Job,TimerTask实现了Runnable接口,该类中主要有三个方法:任务执行逻辑,执行时间,取消执行。
实现任务调度的步骤:
1、创建TimerTask类。2、创建Timer类。3、将TimerTask实例注册到Timer中。
实例
创建任务实例
package scheduler; import java.util.TimerTask; public class SimpleTimerTask extends TimerTask{ private int count=0; @Override public void run() { // TODO Auto-generated method stub System.out.println("线程执行次数========="+count); count++; if(count>10){ cancel(); } } }
将任务注册到Timer中
package scheduler; import java.util.Timer; import java.util.TimerTask; public class TimerRunner { public static void main(String[] args){ Timer timer = new Timer(); TimerTask timerTask = new SimpleTimerTask(); timer.schedule(timerTask, 1000, 2000); } }
Spring对Timer的使用
创建任务类
package scheduler; import org.springframework.stereotype.Component; @Component("myService") public class MyService { public void timerTest(){ System.out.println("开始使用TimerTask========="); } }
将任务类封装为TimerTask,并将TimerTask设置定时规则,将规则注入Timer。
<!-- 通过生成任务TimerTask --> <bean id="timerTask" class="org.springframework.scheduling.timer.MethodInvokingTimerTaskFactoryBean" p:targetObject-ref="myService" p:targetMethod="timerTest"/> <!-- 定义调度规则 --> <bean id="scheduledTask" class="org.springframework.scheduling.timer.ScheduledTimerTask" p:timerTask-ref="timerTask" p:delay="1000" p:period="1000"/> <!-- 将调度规则放入调度队列 --> <bean id="timerFactoryBean" class="org.springframework.scheduling.timer.TimerFactoryBean"> <property name="scheduledTimerTasks"> <list> <ref bean="scheduledTask"/> </list> </property> </bean>
Spring中使用Executor
Executor主要有两个任务:任务提交和任务执行。Executor只有一个方法:void execute(Runnable command),该方法接收任何实现了Runnable的实例。
Executor的简单实现:
package scheduler; import java.util.concurrent.Executor; public class SimpleExecutor implements Executor{ @Override public void execute(Runnable command) { // TODO Auto-generated method stub command.run(); } }
可以为每个任务创建一个线程:
package scheduler; import java.util.concurrent.Executor; public class TaskExecutor implements Executor{ @Override public void execute(Runnable command) { // TODO Auto-generated method stub //为每一个任务重新创建一个线程 new Thread(command).start(); } }
可以将任务放到线程池调度中,每一个任务会通过获取线程,进行任务处理。SchedulerThreadPoolExecutor继承ThreadPoolExecutor,ThreadPoolExecutor继承了Executor和ExecutorService。而SchedulerThreadPoolExecutor通过newFixedThreadPool(int nThreads)创建一个线程池进行任务处理。
使用实例:
package scheduler; public class SimpleRunnable implements Runnable{ @Override public void run() { // TODO Auto-generated method stub System.out.println("开启任务执行=========="); } }
package scheduler; import java.util.concurrent.Executor; import java.util.concurrent.Executors; public class ExecutorExample { private Executor executor; public void setExecutor(Executor executor){ this.executor = executor; } public void executeTask(){ for(int i=0;i<6;i++){ executor.execute(new SimpleRunnable()); } } public static void main(String args){ ExecutorExample ee = new ExecutorExample(); ee.setExecutor(Executors.newFixedThreadPool(3)); ee.executeTask(); } }
Spring任务调度的注解支持
@Schedule的实例
配置定时任务:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:task="http://www.springframework.org/schema/task" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.0.xsd"> <context:component-scan base-package="scheduler"/> <!-- 启用注解驱动的定时任务 --> <task:annotation-driven scheduler="myScheduler"/> <!-- 推荐配置线程池,若不配置多任务下会有问题。后面会详细说明单线程的问题。 --> <task:scheduler id="myScheduler" pool-size="5"/> </beans>
创建任务类
package scheduler; import java.util.Map; import org.quartz.Job; import org.quartz.JobExecutionContext; import org.quartz.JobExecutionException; import org.springframework.stereotype.Component; import bean.User; @Component("myJob") public class MyJob{ public void myexecute() { // TODO Auto-generated method stub System.out.println("Spring开始任务调度========="); System.out.println("Spring结束任务调度=========="); } }