Use servlet context to implement listeners

In addition to spring scheduling, you can also use servlet context to implement scheduled tasks in projects.

1. Create a listener class to implement the servletcontextlistener interface and implement the methods in the interface:

Import javax. servlet. servletcontextevent;
Import javax. servlet. servletcontextlistener;

/**
* The Listener class and timer are combined to regularly execute tasks.
*/
Public class contextlistener implements servletcontextlistener {
Private java. util. Timer timer = NULL;
Public void contextinitialized (servletcontextevent arg0 ){
Timer = new java. util. Timer (true); // create a timer and specify its related threads as daemon programs.
// System. Out. println ("START timer ");
// Scheduler, earlywarningtask () is a custom scheduling task
// Execute a task during initialization
Timer. Schedule (New earlywarningtask (), 10, 60*60*1000); // the delay before the task is executed is 10 milliseconds, and the interval between tasks is 60*60*1000 milliseconds.
// System. Out. println ("scheduling task added successfully ");
}
Public void contextdestroyed (servletcontextevent arg0 ){
Timer. Cancel ();
// System. Out. println ("scheduled task destruction ");

}

}

2. Obtain the applicationcontext configuration information of spring to read the related business methods in the configuration file in the scheduling task.

Import org. springframework. Context. Support. abstractapplicationcontext;
Import org. springframework. Context. Support. classpathxmlapplicationcontext;

Public class appcontext {
Private Static appcontext instance;

Private abstractapplicationcontext appcontext;

Public synchronized static appcontext getinstance (){
If (instance = NULL ){
Instance = new appcontext ();
}
Return instance;
}

Private appcontext (){
This. appcontext = new classpathxmlapplicationcontext (
"/Applicationcontext. xml ");
}

Public abstractapplicationcontext getappcontext (){
Return appcontext;
}
}

3. Custom scheduling task class, inheriting timertask class

Import java. util. timertask;

Public class earlywarningtask extends timertask {
Private Static final int c_schedule_hour = 23; // the execution time is 23 hours.
Private Static Boolean isrunning = false;

// Obtain the related business methods in the configuration file through the appcontext class

// Instoragedetailimp
Protected iinstoragedetailservice getinstoragedetailservice (){
Return (iinstoragedetailservice) appcontext. getinstance (). getappcontext ()
. Getbean ("instoragedetailimp ");
}
// Goodswarningimp
Protected igoodswarningservice getgoodswarningservice (){
Return (igoodswarningservice) appcontext. getinstance (). getappcontext ()
. Getbean ("goodswarningimp ");
}
// Lendoutaccounibd
Protected ilendoutaccountservice getlendoutaccountservice (){
Return (ilendoutaccountservice) appcontext. getinstance (). getappcontext ()
. Getbean ("lendoutaccounibd ");
}
// Lendoutwarningimp
Protected ilendoutwarningservice getlendoutwarningservice (){
Return (ilendoutwarningservice) appcontext. getinstance (). getappcontext ()
. Getbean ("lendoutwarningimp ");
}

// The task is implemented in the run () method.
@ Override
Public void run (){
Calendar Cal = calendar. getinstance ();
If (! Isrunning ){
If (c_schedule_hour = Cal. Get (calendar. hour_of_day) {// hour_of_day is used for the 24-hour clock.
Isrunning = true;
System. Out. println ("scheduled task execution ");
// Task code
//..............................
Isrunning = false;
System. Out. println ("scheduled task ended ");
} Else {
System. Out. println ("scheduled task time not reached ");
}
} Else {
System. Out. println ("the previous scheduled task has not ended ");
}
}

4. Web. xml configuration listening

<Listener>
<Listener-class> com. Cl. GDB. util. contextlistener </listener-class>

</Listener>