Spring task instructions

Spring task instructions

Because the project needs to perform scheduled task operations, the previous knowledge of java timer task is not very good. Today, I found that the task in spring is quite good, so I learned it,

First, spring3 and later versions are required. Annotations and configurations are supported. Let's talk about the configuration format:

1. Add the red part to the spring configuration file.

<Beans xmlns = "http://www.springframework.org/schema/beans"
Xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns: context = "http://www.springframework.org/schema/context"
Xmlns: mvc = "http://www.springframework.org/schema/mvc"
Xmlns: task = "http://www.springframework.org/schema/task"
Xsi: schemaLocation = "http://www.springframework.org/schema/beans
Http://www.springframework.org/schema/beans/spring-beans.xsd
Http://www.springframework.org/schema/context
Http://www.springframework.org/schema/context/spring-context-3.2.xsd
Http://www.springframework.org/schema/mvc
Http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
Http://www.springframework.org/schema/task
Http://www.springframework.org/schema/task/spring-task-3.0.xsd>

2. annotation scan package <context: component-scan base-package = "com. lenovo. task"/>

3. Configure the task

<Task: scheduled-tasks>
<! -- <Task: scheduled ref = "taskJob" method = "getAccessTokenJob" cron = "0 27 23/2 **? "/> -->
<Task: scheduled ref = "taskJob" method = "getAccessTokenJob" fixed-rate = "# {1000*60*60*2}"/>
</Task: scheduled-tasks>

The three attributes cron, fixed-rate, and fixed-delay are supported.

3.1.cron Expression Form

I won't talk about the cron expression. You may have a lot of cron expressions on your own, but note that the task execution in this way has a fixed time point. For example, the above expression is executed, the task is executed every two hours, instead of restarting the server. Also pay attention to the month, and week, must there be a question mark?

3.2fixed-rate and fixed-delay are executed at intervals, in milliseconds. I don't know the difference between them. Let's talk about it.

4. the java class is as follows:

Package com. lenovo. task;

Import java. util. Date;

Import org. springframework. stereotype. Service;

Import com. lenovo. util. Constants;
Import com. lenovo. util. WxPayHelper;

@ Service
Public class TaskJob {

Public void getAccessTokenJob (){

WxPayHelper wxPayHelper = new WxPayHelper ();
WxPayHelper. SetAppId (Constants. appId );
WxPayHelper. setAppSecret (Constants. secret );
WxPayHelper. setURL (Constants. accessUrl );
System. out. println (Constants. accesen En + "-----");
System. out. println (Constants. jsapi_ticket + "nidaye ");
System. out. println (new Date ());

Try {
Constants. accesstoken = wxPayHelper. getAccessToken ();
Constants. jsapi_ticket = wxPayHelper. getJsToken (Constants. accesstoken );
} Catch (Exception e ){
E. printStackTrace ();
}

}


}