Servlet Listener and Timer timer for Java Web application simple automatic job

In Web applications, sometimes customers need timed programs that do not require the customer to operate on their own, but are triggered by the application to perform certain actions on their own. This time, the use of monitoring and timer can basically achieve this requirement.

1. Create a listening Servelet, this class inherits Javax.servlet.http.HttpServlet and implements Javax.servlet.ServletContextListener.

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2. Package com.bndz.outMail;
6. Import Java.util.Timer;
10. Import javax.servlet.ServletContextEvent;
12. Import Javax.servlet.ServletContextListener;
14. Import Javax.servlet.http.HttpServlet;
18. /**
20. *
22. * Files sent by the listener need to be configured in Web-xml
24. */
26. public class Mailsendlistener extends HttpServlet implements
28. Servletcontextlistener {
32. /**
34. * Monitoring begins to destroy
36. */
38. public void contextdestroyed (Servletcontextevent sce) {
42. }
46. /**
48. * Monitoring starts execution
50. */
52. public void contextinitialized (Servletcontextevent sce) {
56. When the listener starts executing, set a time
58. Timer timer = new timer ();
60. System.out.println ("-------MailSend timer begins execution--------------");
62. Mailsendtask msendtask = new Mailsendtask ();
64. Timer.schedule (Msendtask, 60 * 1000, 10 * 1000);
66. System.out.println ("-------MailSend timer is already executing--------------");
68. }
70. }

2. Configure the Web. xml file for configuration.

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1. <listener>
2. <listener-class>com.bndz.outmail.mailsendlistener</listener-class>
3. </Listener>

3. Create a mailsendtask, inherit the Java.util.TimerTask, and execute the program within the Run method.

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2. Package com.bndz.outMail;
6. Import Java.util.Date;
8. Import Java.util.TimerTask;
12. /**
14. * JAVA a timed task
16. *
18. * @author guox2011-05-10
20. *
22. */
24. public class Mailsendtask extends TimerTask {
28. Public Mailsendtask () {
32. }
36. /**
38. * The Run method is put into a schedule when executing a timed program to perform the import
40. */
42. public void Run () {
46. System.out.println (New Date () + "---mailsendtask begin to RUN------------");
48. Mailsendmanager Mainsendmanager = new Mailsendmanager ();
50. Mainsendmanager.waitingmailremind ();
52. }
56. }

4. In the Contextinitialized method of listening for Servelet, write a timer, and let it schedule method to perform the Mailsendtask task described above.

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1. When the listener starts executing, set a time
2. Timer timer = new timer ();
3. System.out.println ("-------MailSend timer begins execution--------------");
4. Mailsendtask msendtask = new Mailsendtask ();
5. Timer.schedule (Msendtask, 60 * 1000, 10 * 1000);
6. System.out.println ("-------MailSend timer is already executing--------------");

Servlet Listener and Timer timer for Java Web application simple automatic job