When Tomcat is started, a specific method is executed. When tomcat is started

When Tomcat is started, a specific method is executed. When tomcat is started

import java.util.Timer;import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;public class TestListener implements ServletContextListener {  private Timer timer = null;  public void contextInitialized(ServletContextEvent event) {    timer = new Timer(true);    timer.schedule(new TestTimer(), 0, 86400000);//milliseconds  }  public void contextDestroyed(ServletContextEvent event) {    timer.cancel();  }}------------------------------------------import java.util.TimerTask;public class TestTimer extends TimerTask {  public void run() {    // do something ...  }}------------------------------------------web.xml:<listener><listener-class>test.TestListener</listener-class></listener>

When tomcat is started in a java program, the methods in a class are executed.

Java has a Listener! Call your own method when tomcat starts! It can also be called cyclically! Web. xml <listener>
<Listener-class> com. function. SysContextListener </listener-class>
</Listener> SysContextListener. javapackage com. function; import java. util. Timer; // Timer class
Import javax. servlet. ServletContextEvent;
Import javax. servlet. ServletContextListener;
Public class SysContextListener implements ServletContextListener
{
Private Timer timer = null;
Public void contextInitialized (ServletContextEvent event)
{// Initialize the listener here. The Listener starts when tomcat is started. The timer function can be implemented here.
Timer = new Timer (true );
System. out. println ("started successfully ");
Event. getServletContext (). log ("timer started --------------------------------------------------"); // Add logs, which can be viewed in tomcat logs
// Timer. schedule (new exportHistoryBean (event. getServletContext (), DealDate. getTime (), 1000*1000); // call exportHistoryBean. 0 indicates that the task has no latency, 5*1000 indicates that the task is executed every 5 seconds, and 60*60 * indicates an hour.
Event. getServletContext (). log ("added task --------------------------------------------------");
}
Public void contextDestroyed (ServletContextEvent event)
{// Disable the listener here, So destroy the timer here.
Timer. cancel ();
Event. getServletContext (). log ("timer destruction --------------------------------------------------");
} ExportHistoryBean. javapackage com. function; import java. util. Calendar;
Import java. util. TimerTask;
Import javax. servlet. ServletContext;
Public class exportHistoryBe... the remaining full text>

How to execute a program at tomcat startup

Write a serlvet and start this thread in the Init method.
Set start up to 1 s.