Google Guava：EventBus

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>25.1-jre</version>
</dependency>

package com.example.demo.eventbus.config;

import com.google.common.eventbus.EventBus;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * 注入eventBus bean
 *
 */
@Configuration
public class EventBusConfig {

    @Bean("eventBus")
    public EventBus eventBus() {
        return new EventBus("demo");
    }
}


package com.example.demo.eventbus.listener;

import com.google.common.eventbus.EventBus;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationListener;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;

import java.util.Map;

/**
 * 注册eventListener
 *
 */
@Component
public class ApplicationListenerRegister implements ApplicationListener<ContextRefreshedEvent> {

    @Autowired
    private EventBus eventBus;

    @Autowired
    private ConfigurableApplicationContext context;

    @Override
    public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {
        Map<String, IEventListener> listenerMap = context.getBeansOfType(IEventListener.class);
        if (!CollectionUtils.isEmpty(listenerMap)) {
            for (Map.Entry<String, IEventListener> entry : listenerMap.entrySet()) {
                eventBus.register(entry.getValue());
                System.out.println("eventListener registed: " + entry.getValue().getClass());
            }
        }
    }
}


package com.example.demo.eventbus.listener;

/**
 * 事件监听者接口
 *
 */
public interface IEventListener {
}


package com.example.demo.eventbus.listener;

import com.google.common.eventbus.Subscribe;
import org.springframework.stereotype.Component;

/**
 * 监听Integer
 *
 */
@Component
public class ListenerInt implements IEventListener{

    @Subscribe
    public int call(Integer num) {
        System.out.println("ListenerInt call(): " + num);
        return num;
    }

}


package com.example.demo.eventbus.listener;

import com.google.common.eventbus.Subscribe;
import org.springframework.stereotype.Component;

/**
 * 监听字符串事件
 *
 */
@Component
public class ListenerStr implements IEventListener{

    @Subscribe
    public String call(String str) {
        System.out.println("ListenerStr call() : " + str);
        return str;
    }

    @Subscribe
    public String call2(String str) {
        System.out.println("ListenerStr call2() : " + str);
        return str;
    }
}


package com.example.demo.eventbus;

import com.google.common.eventbus.EventBus;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * eventBus测试
 *
 */
@RestController
@RequestMapping("/event")
public class EventBusTestController {


    @Autowired
    private EventBus eventBus;

    @GetMapping("/eventTest")
    public void eventTest() {
        System.out.println("eventTest started");
        eventBus.post("string test");

        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        eventBus.post(111);
        System.out.println("eventTest end");
    }
}