彻底理解spring的定制任务（scheduling）

相信做软件的朋友都有这样的经历，我的软件是不是少了点什么东西呢？比如定时任务啊， 字串3

就拿新闻发布系统来说，如果新闻的数据更新太快，势必涉及一个问题，这些新闻不能由人工的去发布，应该让系统自己发布，这就需要用到定时定制任务了，以前定制任务无非就是设计一个Thread，并且设置运行时间片，让它到了那个时间执行一次，就ok了，让系统启动的时候启动它，想来也够简单的。不过有了 spring，我想这事情就更简单了。 字串3

看看spring的配置文件，想来就只有这个配置文件了

xml 代码

1. < bean id = "infoCenterAutoBuildTask"
2. class = "com.teesoo.teanet.scheduling.InfoCenterAutoBuildTask" >
3. < property name = "baseService" ref = "baseService" />
4. < property name = "htmlCreator" ref = "htmlCreator" />
5. </ bean >
7. < bean id = "scheduledTask"
8. class = "org.springframework.scheduling.timer.ScheduledTimerTask" >
9. <!-- wait 10 seconds before starting repeated execution -->
10. < property name = "delay" value = "10000" />
11. <!-- run every 50 seconds -->
12. < property name = "period" value = "1000000" />
13. < property name = "timerTask" ref = "infoCenterAutoBuildTask" />
14. </ bean >
17. < bean id = "timerFactory" class = "org.springframework.scheduling.timer.TimerFactoryBean" >
18. < property name = "scheduledTimerTasks" >
19. < list >
20. <!-- see the example above -->
21. < ref bean = "scheduledTask" />
22. </ list >
23. </ property >
24. </ bean >

上面三个配置文件中只有一个配置文件是涉及到您自己的class的，其他的都是spring的类。很简单吧

字串1

我们只需要涉及一个class让他继承java.util.TimerTask;

字串2

java 代码

1. BaseTask extends java.util.TimerTask {
2. //用户只需要实现这个方面，把自己的任务放到这里
3. public void run(){
4. }
5. }

字串2

字串2

字串8

下面让我们来看看 spring的源代码 字串7

java 代码

1. /*
2. * Copyright 2002-2005 the original author or authors.
3. *
4. * Licensed under the Apache License, Version 2.0 (the "License");
5. * you may not use this file except in compliance with the License.
6. * You may obtain a copy of the License at
7. *
8. * http://www.apache.org/licenses/LICENSE-2.0
9. *
10. * Unless required by applicable law or agreed to in writing, software
11. * distributed under the License is distributed on an "AS IS" BASIS,
12. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13. * See the License for the specific language governing permissions and
14. * limitations under the License.
15. */
17. package org.springframework.scheduling.timer;
19. import java.util.TimerTask;
21. /**
22. * JavaBean that describes a scheduled TimerTask, consisting of
23. * the TimerTask itself (or a Runnable to create a TimerTask for)
24. * and a delay plus period. Period needs to be specified;
25. * there is no point in a default for it.
26. *
27. *

    The JDK Timer does not offer more sophisticated scheduling 字串2

28. * options such as cron expressions. Consider using Quartz for
29. * such advanced needs.
30. *
31. *

    Note that Timer uses a TimerTask instance that is shared

    字串8

32. * between repeated executions, in contrast to Quartz which
33. * instantiates a new Job for each execution.
34. *
35. * @author Juergen Hoeller
36. * @since 19.02.2004
37. * @see java.util.TimerTask
38. * @see java.util.Timer#schedule(TimerTask, long, long)
39. * @see java.util.Timer#scheduleAtFixedRate(TimerTask, long, long)
40. */
41. public class ScheduledTimerTask {
43. private TimerTask timerTask;
45. private long delay = 0 ;
47. private long period = 0 ;