spring中ApplicationListener的使用小结

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor

/**
 * 模拟业务对象实体类
 * @author csdn:孟秋与你
 */
public class MyBizEntity {
    private String name;
    private Integer age;
}

import org.springframework.context.ApplicationEvent;

/**
 * 自定义事件（继承ApplicationEvent）
 * @author csdn:孟秋与你
 */
public class MyEvent extends ApplicationEvent {


    public MyEvent(Object source) {
        super(source);
    }
    public MyEvent() {
        // java基础：如果父类只有有参构造 子类需要使用其它构造函数 必须在构造函数第一行调用super 因为子类也是调用父类的构造函数
        super(null);
        // do other
    }
}

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

/**
 * 监听事件
 */
@Component
public class MyApplicationListener implements ApplicationListener {
    @Override
    public void onApplicationEvent(ApplicationEvent applicationEvent) {

        // 必须判断自己要的类型  因为会监听到所有继承ApplicationEvent的事件
        if (applicationEvent instanceof MyEvent) {
            Object source = applicationEvent.getSource();
            MyBizEntity bizEntity = (MyBizEntity) source;
            System.out.println(bizEntity.getName() + "：------------name");
        }

    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RequestMapping("/test/listener")
@RestController
public class MainBizController {

    @Autowired
    private ApplicationContext context;

    @GetMapping
    public String test() {
        // do something
        
        // 模拟要传递的业务对象
        MyBizEntity bizEntity = new MyBizEntity("name",18);
        MyEvent event = new MyEvent(bizEntity);
        // 上下文 发布事件
        context.publishEvent(event);
        return "success";
    }
}

@Configuration
public class EventConfig {

    @Bean(name = "applicationEventMulticaster")
    public SimpleApplicationEventMulticaster simpleApplicationEventMulticaster(TaskExecutor taskExecutor) {
        SimpleApplicationEventMulticaster eventMulticaster = new SimpleApplicationEventMulticaster();
        eventMulticaster.setTaskExecutor(taskExecutor);
        return eventMulticaster;
    }
}

@Configuration
public class AsyncInBootConfig {

    /** 核心线程池大小 */
    private int corePoolSize = 20;

    /**
     * 最大可创建的线程数
     */
    private int maxPoolSize = 50;

    /**
     * 队列最大长度
     */
    private int queueCapacity = 100;

    /**
     * 线程池维护线程所允许的空闲时间
     */
    private int keepAliveSeconds = 300;

    @Primary
    @Bean(name = "threadPool")
    /**
     * springboot 线程池方式
     */
    public ThreadPoolTaskExecutor threadPoolTaskExecutor()
    {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setMaxPoolSize(maxPoolSize);
        executor.setCorePoolSize(corePoolSize);
        executor.setQueueCapacity(queueCapacity);
        executor.setKeepAliveSeconds(keepAliveSeconds);
        // 线程池对拒绝任务(无线程可用)的处理策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        return executor;
    }
}