event listener

Processing logic:

　　Custom events (including required data bodies) ---> custom listeners (you can limit the events that need to be monitored through generics, of course, you can also not involve) ---> publish events to IOC ---> in The process of completing the actual business in the listener.

1. Custom events.

　　Inherit ApplicationEvent

package com.shanxilgong.linxi.listener;

import org.springframework.context.ApplicationEvent;

import java.util.HashMap;
import java.util.Map;

/**
 * custom events
 */
public class MyApplicationEvent extends ApplicationEvent
{

    public MyApplicationEvent(Object source)
    {
        super(source);
    }

    private Map<String,String> data = new HashMap<String,String>();

    public Map<String, String> getData() {
        return data;
    }

    public void setData(Map<String, String> data) {
        this.data = data;
    }
}

2. Simulate the southbound acquisition task

　 2.1 The ioc container in spring boot

　　　 ConfigurableApplicationContext application = SpringApplication.run(SmalprocesssApplication.class, args);

　　Start the scheduled task:

　　Timing task: Line 34, build an event object. Line 37 publishes events to the IOC container.

1  package com.shanxilgong.linxi.listener;
 2  
3  import org.springframework.beans.factory.annotation.Autowired;
 4  import org.springframework.context.ConfigurableApplicationContext;
 5  import org.springframework.stereotype.Component;
 6  
7  import java. util.HashMap;
 8  import java.util.Map;
 9  import java.util.TimerTask;
 10  
11  
12  /** *
 13  * This scheduled task is used to simulate the southbound periodic collection task and publish collection result events.
14   */ 
15  
16  @Component
 17 public class MyTimerTask extends TimerTask
18 {
19 
20     @Autowired
21     private ConfigurableApplicationContext configurableApplicationContext;
22 
23     public MyTimerTask(){
24 
25     }
26 
27     @Override
28     public void run()
29     {
30         Map map = new HashMap();
31         map.put("name","zhangsan");
32         map.put("age","20");
33 
34          MyApplicationEvent event = new MyApplicationEvent( new Object());
 35          event.setData(map);
 36          // spring's ioc container, publish events 
37          configurableApplicationContext.publishEvent(event);
 38      }
 39 }

3. Custom listener

　　Implement ApplicationListener, and add the event generics that need to be monitored, such as line 14. (Of course, you can also not add listener event generics)

1  package com.shanxilgong.linxi.listener;
 2  
3  import org.springframework.context.ApplicationEvent;
 4  import org.springframework.context.ApplicationListener;
 5  import org.springframework.stereotype.Component;
 6  
7  import java.lang.reflect. Method;
 8  
9  /** 
10  * Custom listener
 11  * 1. You can specify which type of event to listen to through generics
 12   */ 
13  
14  public  class MyApplicationListener implements ApplicationListener<MyApplicationEvent>
 15  {
 16     @Override
 17      public  void onApplicationEvent(MyApplicationEvent event)
 18      {
 19          System.out.println("The captured data is: "+ event.getData());
 20      }
 21 }

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