定时器quartz的应用

用quartz可以实现web或非web模式的定时器

1、配置文件

quartz_job.xml

1. <!--sp-->xmlversion="1.0"encoding="UTF-8"?>
2. <quartzxmlns="http://www.opensymphony.com/quartz/JobSchedulingData"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. overwrite-existing-jobs="true">
6. <job>
7. <job-detail>
8. <name>yayaittname>
9. <group>CRAWLER_JOB_GROUPgroup>
11. <description>sendtaskperdaydescription>
12. <job-class>com.yahaitt.quartz.QuartzSystemjob-class>
14. <job-data-mapallows-transient-data="true">
15. <entry>
16. <key>usernamekey>
17. <value>wujinlivalue>
18. entry>
19. <entry>
20. <key>passwordkey>
21. <value>mahaibovalue>
23. entry>
24. job-data-map>
25. job-detail>
26. <trigger>
27. <cron>
28. <name>hourTaskJob-triggername>
29. <group>CRAWLER_TRIGGER_GROUPgroup>
30. <job-name>yayaittjob-name>
31. <job-group>CRAWLER_JOB_GROUPjob-group>
34. <cron-expression>1/12****?cron-expression>
36. cron>
37. trigger>
38. job>
44. quartz>

该定时器实现了每12秒触发类com.yahaitt.quartz.QuartzSystem的execute函数，并通过java-data-map标签来实现参数的传递，如果不需要传递参数，可以将整个java-data-map标签去除。

需要注意的是job-detail与trigger中各子标签间的关系，比如trigger中job-name和job-group要与job-detail中的name和group对应。

可以通过在quartz标签中添加多个job来实现多个定时器的管理。

2、定义org.quartz.Job接口的实现类

QuartzSystem.java

1. packagecom.yahaitt.quartz;
3. importorg.quartz.Job;
4. importorg.quartz.JobExecutionContext;
5. importorg.quartz.JobExecutionException;
7. publicclassQuartzSystemimplementsJob{
9. publicvoidexecute(JobExecutionContextcontext)throwsJobExecutionException{
10. //TODOAuto-generatedmethodstub
12. Stringusername=context.getJobDetail().getJobDataMap().getString("username");
13. Stringpassword=context.getJobDetail().getJobDataMap().getString("password");
14. System.out.println("username:"+username);
15. System.out.println("password:"+password);
16. }
18. }

通过调用JobExecutionContext 的getJobDetail().getJobDataMap().getString(String paramname)来取得配置文件中定义的参数的值。

当定时器触发时，将执行该类的execute函数。

3、设置监听器

TaskScheduler.java

1. packagecom.yahaitt.quartz;
3. importjava.util.Properties;
5. importorg.apache.log4j.Logger;
6. importorg.quartz.Scheduler;
7. importorg.quartz.SchedulerException;
8. importorg.quartz.SchedulerFactory;
9. importorg.quartz.impl.StdSchedulerFactory;
10. importorg.quartz.xml.JobSchedulingDataProcessor;
13. publicclassTaskScheduler{
14. //Logger
15. privatestaticLoggerlogger=Logger.getLogger(TaskScheduler.class);
17. privatestaticSchedulerscheduler;
19. privateStringjobsConfigFile="quartz-jobs.xml";
21. publicTaskScheduler(){
22. initScheduler();
23. }
25. /**
26. *
27. *@paramfileName
28. *@return
29. */
30. publicvoidinitScheduler(){
31. try{
32. StdSchedulerFactoryfactory=newStdSchedulerFactory();
33. //
34. Propertiesproperties=newProperties();
35. properties.put("org.quartz.scheduler.instanceName","DefaultQuartzScheduler");
36. properties.put("org.quartz.scheduler.rmi.export","false");
37. properties.put("org.quartz.scheduler.rmi.proxy","false");
38. properties.put("org.quartz.scheduler.wrapJobExecutionInUserTransaction","false");
39. properties.put("org.quartz.threadPool.class","org.quartz.simpl.SimpleThreadPool");
40. properties.put("org.quartz.threadPool.threadCount","20");
41. properties.put("org.quartz.threadPool.threadPriority","5");
42. properties.put("org.quartz.threadPool.threadsInheritContextClassLoaderOfInitializingThread","true");
43. properties.put("org.quartz.jobStore.misfireThreshold","60000");
44. properties.put("org.quartz.jobStore.class","org.quartz.simpl.RAMJobStore");
45. //org.quartz.plugin.jobInitializer.validating=false
46. //org.quartz.plugin.jobInitializer.validatingSchema=false
47. //org.quartz.plugin.jobInitializer.class=org.quartz.plugins.xml.JobInitializationPlugin
48. //org.quartz.plugin.jobInitializer.fileName=quartz-jobs.xml
49. //org.quartz.plugin.jobInitializer.overWriteExistingJobs=false
50. //org.quartz.plugin.jobInitializer.failOnFileNotFound=true
51. factory.initialize(properties);
52. SchedulerFactorysf=(StdSchedulerFactory)factory;
53. scheduler=sf.getScheduler();
54. //PlacingaSchedulerinStand-byMode
55. //scheduler.standby();
56. }catch(SchedulerExceptione){
57. e.printStackTrace();
58. logger.error(e);
59. }
60. }
62. /**
63. *从指定的任务配置文件中初始化计划任务
64. *@paramjobsConfig
65. *@throwsException
66. */
67. publicvoidinitJobs(StringjobsConfig)throwsException{
68. //
69. this.jobsConfigFile=jobsConfig;
70. //
71. JobSchedulingDataProcessorxmlProcessor=newJobSchedulingDataProcessor();
72. //thelastparameterhere(thebooleanone)isforoverwritingexistingjobs
73. xmlProcessor.processFileAndScheduleJobs(jobsConfigFile,scheduler,true);
74. }
76. /**
77. *开启计划任务
78. *@throwsSchedulerException
79. */
80. publicvoidstartScheduler()throwsSchedulerException{
81. //Schedulerwillnotexecutejobsuntilithasbeenstarted(thoughtheycanbescheduledbeforestart())
82. scheduler.start();
83. }
85. /**
86. *停止计划任务
87. *@throwsSchedulerException
88. */
89. publicvoidshutdownScheduler()throwsSchedulerException{
90. scheduler.shutdown();
91. }
93. /**
94. *@paramargs
95. */
96. publicstaticvoidmain(String[]args){
97. StringjobsConfigfile="E:/workspace/crawler/conf/quartz_job.xml";
98. TaskSchedulerscheduler=newTaskScheduler();
99. try{
100. scheduler.initJobs(jobsConfigfile);
101. scheduler.startScheduler();
102. }catch(Exceptione){
103. e.printStackTrace();
104. }
106. }
108. }

• 使用多线程和定时器的例子.rar (1.7 MB)

只有当执行
scheduler.initJobs(jobsConfigfile);
scheduler.startScheduler();
后，定时器才会被启动。
所以，在web中应用时，可以写一个servlet程序，在其init函数中new一个TaskScheduler，并初始化和启动这个TaskScheduler，并通过在web.xml中设置
<load-on-startup>1</load-on-startup>
使得在web服务器启动时将定时器启动。