SpringBoot监听器的实现示例

import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

@Component
public class MyApplicationListener implements ApplicationListener<ApplicationReadyEvent> {

    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        System.out.println("Application is ready!");
    }
}

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

@Component
public class MyEventListener {

    @EventListener
    public void handleApplicationReadyEvent(ApplicationReadyEvent event) {
        System.out.println("Application is ready!");
    }
}

import org.springframework.context.ApplicationEvent;

public class CustomEvent extends ApplicationEvent {
    private String message;

    public CustomEvent(Object source, String message) {
        super(source);
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

import org.springframework.context.ApplicationListener;

public class CustomEventListener implements ApplicationListener<CustomEvent> {

    @Override
    public void onApplicationEvent(CustomEvent event) {
        System.out.println("Received custom event: " + event.getMessage());
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class EventPublisher {
 @Autowired
    private final ApplicationContext context;

   
    public EventPublisher(ApplicationContext context) {
        this.context = context;
    }

    public void publishCustomEvent(String message) {
        context.publishEvent(new CustomEvent(this, message));
    }
}

@Autowired
private EventPublisher eventPublisher;

// ...

eventPublisher.publishCustomEvent("Hello from a custom event!");

import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
 
import java.time.LocalDateTime;
 
@Configuration      //1.主要用于标记配置类，兼备Component的效果。
@EnableScheduling   // 2.开启定时任务
public class ScheduleTask {
    @Scheduled(cron = "0/5 * * * * ?") //定时任务注解+cron表达式
    public void testScheduleTask() {
        System.out.println("执行定时任务" + LocalDateTime.now());
    }
}