springboot 事件监听（@EventListener实现）

梦里梦外; 2023-02-23 03:53 1阅读 0赞

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### springboot 事件监听（@EventListener实现） ###

**应用：使用注解实现事件监听**

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**相关注解**

**@EventListener**

@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    public @interface EventListener {
        @AliasFor("classes")
        Class<?>[] value() default {};  //监听的类
    
        @AliasFor("value")
        Class<?>[] classes() default {};
    
        String condition() default "";
    }

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**示例**

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**event 层**

**CustomEvent**

public class CustomEvent extends ApplicationEvent {
    
        private String message;
    
        public CustomEvent(Object source,String message){
            super(source);
            this.message=message;
        }
    
        public String getMessage() {
            return message;
        }
    
        public void setMessage(String message) {
            this.message = message;
        }
    }

**CustomEventListener**

@Component
    public class CustomEventListener {
    
        @EventListener(CustomEvent.class)
        public void onApplicationEvent(CustomEvent customEvent){
            System.out.println("监听器接受消息："+System.currentTimeMillis());
            System.out.println("接收到的消息为："+customEvent.getMessage());
        }
    }

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**controller 层**

**HelloController**

@RestController
    public class HelloController {
    
        @Resource
        private ApplicationContext applicationContext;
    
        @RequestMapping("/hello")
        public String hello(){
            System.out.println("事件开始发布消息："+System.currentTimeMillis());
            applicationContext.publishEvent(new CustomEvent(this,"你好啊"));
    
            return "success";
        }
    }

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**使用测试**

**localhost:8080/hello**

2020-07-05 10:20:14.512  INFO 18472 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
    2020-07-05 10:20:14.517  INFO 18472 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 5 ms
    事件开始发布消息：1593915614552
    监听器接受消息：1593915614553
    接收到的消息为：你好啊