Sprint Cloud Stream整合RocketMq和websocket实现消息发布订阅

1.引入RocketMQ依赖：首先，在pom.xml文件中添加RocketMQ的依赖：

    org.apache.rocketmq
    rocketmq-spring-boot-starter
    2.2.0 

2.配置RocketMQ连接信息：在application.properties或application.yml中配置RocketMQ的连接信息，包括Name Server地址等：

spring:
  application:
    name: ${sn.publish}
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: ${rocket-mq.name-server}
        bindings:
          output:
            producer:
              group: testSocket
              sync: true
      bindings:
        output:
          destination: test-topic
          content-type: application/json

3.消息发布组件

@Component
public class MqSourceComponent {
    @Resource
    Source source;

    public void publishNotify(SampleNotifyDTO notify) {
        source.output().send(MessageBuilder.withPayload(notify).build());
    }
}

4.消息发布控制器

@RestController
@Api(tags = "rocketmq")
public class MqController {
    @Resource
    MqSourceComponent mq;

    @ApiOperation(value = "测试发布消息")
    @PostMapping("test-publish")
    public JsonVO testSend(SampleNotifyDTO notify) {
        mq.publishNotify(notify);
        return JsonVO.success("消息已发送");
    }
}

项目结构：

接下来是websocket模块的搭建

1. 依赖添加

    org.apache.rocketmq
    rocketmq-spring-boot-starter
    2.2.0 

2.application.yml配置文件

server:
  port: ${sp.ws}
spring:
  application:
    name: ${sn.ws}
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: ${rocket-mq.name-server}
      bindings:
        input:
          destination: test-topic
          content-type: application/json
          group: testSocket

3.将应用程序绑定到消息代理

@EnableBinding(Sink.class): 这是Spring Cloud Stream的注解，它用于将应用程序绑定到消息代理（如Kafka、RabbitMQ等）。Sink.class是Spring Cloud Stream提供的预定义输入通道，允许你接收消息。通过这个注解，你的应用程序可以监听消息通道，并定义消息处理逻辑。

@SpringBootApplication
@EnableDiscoveryClient
@EnableBinding(Sink.class)
public class WsApplication {

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

}

4.消息订阅组件

监听消息通道中的消息，一旦有消息到达，就会触发listenNotify方法，该方法负责处理消息并通过chat服务发送响应。

@Component
@Slf4j
public class MqListenComponent {
    @Resource
    ChatService chat;

    @StreamListener(Sink.INPUT)
    public void listenNotify(SampleNotifyDTO notify) {
        log.info(notify.toString());
        chat.sendMessage(notify.getClientId(), notify);
    }
}

5.消息通知服务

package com.zeroone.star.ws.service;

import cn.hutool.json.JSONUtil;
import lombok.SneakyThrows;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;


@Component
@ServerEndpoint("/chat")
public class ChatService {
    /**
     * 连接会话池
     */
    private static ConcurrentHashMap SESSION_POOL = new ConcurrentHashMap<>();

    @OnOpen
    public void onOpen(Session session) throws IOException {
        // 判断客户端对象是否存在
        if (SESSION_POOL.containsKey(session.getQueryString())) {
            CloseReason closeReason = new CloseReason(CloseReason.CloseCodes.CANNOT_ACCEPT, "ID冲突，连接拒绝");
            session.getUserProperties().put("reason", closeReason);
            session.close();
            return;
        }
        // 将客户端对象存储到会话池
        SESSION_POOL.put(session.getQueryString(), session);
        System.out.println("客户端（" + session.getQueryString() + "）：开启了连接");
    }

    @OnMessage
    public String onMessage(String msg, Session session) throws IOException {
        // 解析消息 ==> ID::消息内容
        String[] msgArr = msg.split("::", 2);
        // 处理群发消息，ID==all表示群发
        if ("all".equalsIgnoreCase(msgArr[0])) {
            for (Session one : SESSION_POOL.values()) {
                // 排除自己
                if (one == session) {
                    continue;
                }
                // 发送消息
                one.getBasicRemote().sendText(msgArr[1]);
            }
        }
        // 指定发送
        else {
            // 获取接收方
            Session target = SESSION_POOL.get(msgArr[0]);
            if (target != null) {
                target.getBasicRemote().sendText(msgArr[1]);
            }
        }
        return session.getQueryString() + "：消息发送成功";
    }

    @OnClose
    public void onClose(Session session) {
        // 连接拒绝关闭会话
        Object reason = session.getUserProperties().get("reason");
        if (reason instanceof CloseReason) {
            CloseReason creason = (CloseReason) reason;
            if (creason.getCloseCode() == CloseReason.CloseCodes.CANNOT_ACCEPT) {
                System.out.println("拒绝客户（" + session.getQueryString() + "）：关闭连接");
                return;
            }
        }
        // 从会话池中移除会话
        SESSION_POOL.remove(session.getQueryString());
        System.out.println("客户端（" + session.getQueryString() + "）：关闭连接");
    }

    @OnError
    public void onError(Session session, Throwable throwable) {
        System.out.println("客户端（" + session.getQueryString() + "）错误信息：" + throwable.getMessage());
    }

    @SneakyThrows
    public void sendMessage(String id, Object message) {
        // 群发
        if ("all".equalsIgnoreCase(id)) {
            for (Session one : SESSION_POOL.values()) {
                // 发送消息
                one.getBasicRemote().sendText(JSONUtil.toJsonStr(message));
            }
        }
        // 指定发送
        else {
            // 获取接收方
            Session target = SESSION_POOL.get(id);
            if (target != null) {
                target.getBasicRemote().sendText(JSONUtil.toJsonStr(message));
            }
        }
    }
}

项目结构：