Spring Boot 事件和监听

Java框架

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2019-5-4

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Application Events and Listeners

1、自定义事件和监听

1.1、定义事件

 1 package com.cjs.boot.event;
 2 
 3 import lombok.Data;
 4 import org.springframework.context.ApplicationEvent;
 5 
 6 @Data
 7 public class BlackListEvent extends ApplicationEvent {
 8 
 9     private String address;
10 
11     public BlackListEvent(Object source, String address) {
12         super(source);
13         this.address = address;
14     }
15 }

1.2、定义监听

 1 package com.cjs.boot.event;
 2 
 3 import org.springframework.context.ApplicationListener;
 4 import org.springframework.context.event.EventListener;
 5 import org.springframework.stereotype.Component;
 6 
 7 8 public class BlackListListener implements ApplicationListener<BlackListEvent> {
 9 
10     @Override
11     public void onApplicationEvent(BlackListEvent event) {
12         System.out.println("监听到BlackListEvent事件: " + event.getAddress());
13         try {
14             Thread.sleep(2000);
15         } catch (InterruptedException e) {
16             e.printStackTrace();
17         }
18     }
19 }

1.3、注册监听

 1 package com.cjs.boot;
 2 
 3 import com.cjs.boot.event.BlackListListener;
 4 import org.springframework.boot.SpringApplication;
 5 import org.springframework.boot.autoconfigure.SpringBootApplication;
 6 import org.springframework.boot.web.server.ErrorPage;
 7 import org.springframework.boot.web.server.ErrorPageRegistrar;
 8 import org.springframework.boot.web.server.ErrorPageRegistry;
 9 import org.springframework.cache.annotation.EnableCaching;
10 import org.springframework.context.annotation.Bean;
11 import org.springframework.http.HttpStatus;
12 import org.springframework.scheduling.annotation.EnableAsync;
13 
14 @SpringBootApplication
15 public class CjsSpringbootExampleApplication {
16 
17     public static void main(String[] args) {
18 
19         SpringApplication springApplication = new SpringApplication(CjsSpringbootExampleApplication.class);
20         springApplication.addListeners(new BlackListListener());
21         springApplication.run(args);
22 
23     }

1.4、发布事件

 1 package com.cjs.boot.controller;
 2 
 3 import com.cjs.boot.event.BlackListEvent;
 4 import org.springframework.beans.factory.annotation.Autowired;
 5 import org.springframework.context.ApplicationContext;
 6 import org.springframework.context.ApplicationEventPublisher;
 7 import org.springframework.web.bind.annotation.GetMapping;
 8 import org.springframework.web.bind.annotation.RequestMapping;
 9 import org.springframework.web.bind.annotation.RestController;
10 
11 @RestController
12 @RequestMapping("/activity")
13 public class ActivityController {
14 
15 //    @Autowired
16 //    private ApplicationEventPublisher publisher;
17 
18     @Autowired
19     private ApplicationContext publisher;
20 
21     @GetMapping("/sayHello.json")
22     public void sayHello() {
23 
24         /**
25          * You may register as many event listeners as you wish, but note that by default event listeners receive events synchronously.
26          * This means the publishEvent() method blocks until all listeners have finished processing the event.
27          */
28 
29         BlackListEvent event = new BlackListEvent(this, "abc@126.com");
30         publisher.publishEvent(event);
31         System.out.println("事件发布成功");
32     }
33 
34 }

2、基于注解的事件监听

package com.cjs.boot.event;

import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;

@Component
public class BlackListListener {

    @EventListener
    public void processBlackListEvent(BlackListEvent event) {
        System.out.println(123);
    }
}

---

package com.cjs.boot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class CjsSpringbootExampleApplication {

    public static void main(String[] args) {
        SpringApplication.run(CjsSpringbootExampleApplication.class, args);
    }

}

3、异步监听

1 @EventListener
2 @Async
3 public void processBlackListEvent(BlackListEvent event) {
4     // BlackListEvent is processed in a separate thread
5 }

4、应用

 6 import lombok.extern.slf4j.Slf4j;
 7 import org.springframework.beans.factory.annotation.Autowired;
 8 import org.springframework.context.event.EventListener;
 9 import org.springframework.scheduling.annotation.Async;
10 import org.springframework.stereotype.Component;
11 
12 import java.util.ArrayList;
13 import java.util.List;
14 import java.util.concurrent.ExecutionException;
15 import java.util.concurrent.Future;
16 import java.util.concurrent.atomic.AtomicInteger;
17 
18 /**
19  * 批量送券
20  */
21 @Slf4j
22 @Component
23 public class BatchSendCouponListener {
24 
25     @Autowired
26     private CouponPresentLogService couponPresentLogService;
27 
28     @Async
29     @EventListener
30     public void processBatchSendCouponEvent(BatchSendCouponEvent batchSendCouponEvent) {
31         Long cpId = batchSendCouponEvent.getCouponPresentId();
32         log.info("收到BatchSendCouponEvent, cpId={}", cpId);
33         List<CouponPresentLogEntity> list = couponPresentLogService.selectByPid(cpId);
34 
35         handle(cpId, list, 0);
36     }
37 
38     private void handle(Long cpId, List<CouponPresentLogEntity> list, int times) {
39         if (times >= 2) {
40             log.info("超过重试次数退出, cpId: {}, 剩余: {}", cpId, list.size());
41             return;
42         }
43 
44         List<Future<CouponPresentLogEntity>> futureList = new ArrayList<>();
45 
46         for (CouponPresentLogEntity entity : list) {
47             futureList.add(couponPresentLogService.present(entity));
48         }
49 
50         AtomicInteger count = new AtomicInteger(0);
51         //  收集失败的
52         List<CouponPresentLogEntity> failList = new ArrayList<>();
53         for (Future<CouponPresentLogEntity> future : futureList) {
54             try {
55                 CouponPresentLogEntity couponPresentLogEntity = future.get();
56                 if (couponPresentLogEntity.getStatus() != PresentStatusEnum.SUCCESS.getType().intValue()) {
57                     failList.add(couponPresentLogEntity);
58                 }
59                 count.getAndIncrement();
60                 if (count.intValue() >= list.size()) {
61                     List<CouponPresentLogEntity> failPresentLogList = couponPresentLogService.selectFailLogByPid(cpId);
62                     if (null != failPresentLogList && failPresentLogList.size() > 0) {
63                         times++;
64                         log.info("第{}次重试, CPID: {}, 总计: {}, 失败: {}", times, cpId, list.size(), failPresentLogList.size());
65                         handle(cpId, failPresentLogList, times);
66                     }
67                 }
68             } catch (InterruptedException e) {
69                 log.error(e.getMessage(), e);
70             } catch (ExecutionException e) {
71                 log.error(e.getMessage(), e);
72             }
73         }
74     }
75 
76 }
 1 import lombok.extern.slf4j.Slf4j;
 2 import org.springframework.beans.factory.annotation.Autowired;
 3 import org.springframework.scheduling.annotation.Async;
 4 import org.springframework.scheduling.annotation.AsyncResult;
 5 import org.springframework.stereotype.Service;
 6 
 7 import javax.annotation.Resource;
 8 import java.util.concurrent.*;
 9 
10 @Service
11 @Slf4j
12 public class CouponPresentLogServiceImpl implements CouponPresentLogService {
13 
14     @Autowired
15     private CouponPresentLogDao couponPresentLogDao;
16     @Resource
17     private CouponSendRpcService couponSendRpcService;
18 
19     @Async("myThreadPoolTaskExecutor")
20     @Override
21     public Future<CouponPresentLogEntity> present(CouponPresentLogEntity entity) {
22         try {
23             CouponBaseResponse rst = couponSendRpcService.send(entity.getUserId(), entity.getCouponBatchKey(), "1", entity.getVendorId());
24             if (null != rst && rst.isSuccess()) {
25                 entity.setStatus(PresentStatusEnum.SUCCESS.getType());
26                 entity.setFailureReason(PresentStatusEnum.SUCCESS.getName());
27             }else {
28                 String reason = (null == rst) ? "响应异常" : rst.getMsg();
29                 entity.setFailureReason(reason);
30                 entity.setStatus(PresentStatusEnum.FAILURE.getType());
31             }
32         }catch (Exception ex) {
33             log.error(ex.getMessage(), ex);
34             entity.setFailureReason(ex.getMessage());
35             entity.setStatus(PresentStatusEnum.FAILURE.getType());
36         }
37         couponPresentLogDao.update(entity);
38 
39         return new AsyncResult<CouponPresentLogEntity>(entity);
40     }
41 
42 }

 5、统计异步任务执行的进度

利用Future获取执行结果,比如上面的例子中,由于不是直接提交的任务,所以用AsyncResult来返回结果

上面的例子中,一个大任务,然后下面有许多子任务。在主任务中,统计各子任务的执行情况,是成功还是失败,然后统计成功多少,失败多少

也可以这样写:

@Autowired
ThreadPoolTaskExecutor taskExecutor;

Future<Object> future = taskExecutor.submit(new Callable<Object>() {
    @Override
    public Object call() throws Exception {
        return null;
    }
});
 

作者:不要乱摸