SpringCloud使用RabbitMQ 实现微服务之间的异步调用
最近公司内部员工为了完成小程序分裂考核任务，使用黑客软件发起大量请求刷任务，导致后台小程序模块A的微服务卡死，
微服务B调用了微服务A的微信消息推送功能，其他微服务又调用微服务B......
由于微服务A卡死，服务调用链产生阻塞，新的请求不断来到，阻塞的线程越来越多，最终因服务器资源耗尽而导致整个系统雪崩。
解决方法：使用RabbitMQ实现微服务之间的异步调用，从而实现解耦
具体步骤：
1、两个微服务工程 community 和 deliver 引入相同依赖（deliver异步调用community）
<!-- RabbitMQ消息队列 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bus-amqp</artifactId>
</dependency>
配置文件bootstrap.yml，我司框架有公共的云端配置文件，配置如下：
本地测试的配置如下：
rabbitmq: host: localhost port: 5672 username: guest password: guest
2、 发送方微服务deliver代码
@Service("spTrDispatchDtlServiceImpl")
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.rabbit.connection.CorrelationData;
@Autowired
private RabbitTemplate rabbitTemplate;
// 消息确认
final RabbitTemplate.ConfirmCallback confirmCallback = new RabbitTemplate.ConfirmCallback() {
@Override
public void confirm(CorrelationData correlationData, boolean ack, String cause) {
if (!ack) {
// 消息发送失败
System.err.println("调用community发送微信消息异常处理……");
}
}
};
// 路由失败的监听 TODO rabbitmq接收信息失败后的处理
final RabbitTemplate.ReturnCallback returnCallback = new RabbitTemplate.ReturnCallback() {
@Override
public void returnedMessage(org.springframework.amqp.core.Message message, int replyCode, String replyText, String exchange, String routingKey) {
System.err.println("return exchange:" + exchange + ",routingKey:" + routingKey + ",replyText:" + replyText + ",replyCode:" + replyCode);
}
};
public void pushDispatchMessage(List<SpTrDispatchDtl> dtlList) {
Map<String,Object> messStr = new HashMap<String, Object>();
Map<String,Object> dataStr = new HashMap<String, Object> ();
Map<String,Object> firstStr = new HashMap<String, Object> ();
firstStr.put("value", "订单号");
dataStr.put("first",firstStr);
Map<String,Object> keyword1Str = new HashMap<String, Object> ();
keyword1Str.put("value", "商品名称");
dataStr.put("keyword1", keyword1Str);
Map<String,Object> keyword2Str = new HashMap<String, Object> ();
keyword2Str.put("value","用户名称");
dataStr.put("keyword2", keyword2Str);
Map<String,Object> keyword3Str = new HashMap<String, Object> ();
keyword3Str.put("value","用户电话");
keyword3Str.put("color", "#173177");
dataStr.put("keyword3", keyword3Str);
Map<String,Object> keyword4Str = new HashMap<String, Object> ();
keyword4Str.put("value", "配送地址");
keyword4Str.put("color", "#173177");
dataStr.put("keyword4", keyword4Str);
Map<String,Object> keyword5Str = new HashMap<String, Object> ();
keyword5Str.put("value", "配送时间");
keyword5Str.put("color", "#173177");
dataStr.put("keyword5", keyword5Str);
Map<String,Object> remarkStr = new HashMap<String, Object> ();
dataStr.put("remark", remarkStr);
messStr.put("touser", wxuser.get("openid").toString());//接收者openid
messStr.put("template_id", template_id);//微信模板ID
messStr.put("data",dataStr);
JSONObject jsonObj=new JSONObject(messStr);
rabbitTemplate.setConfirmCallback(confirmCallback);
rabbitTemplate.setReturnCallback(returnCallback);
// 发送消息
System.out.println("配送派工完成，向消息推送发送消息:"+jsonObj.toString());
MessageProperties messageProperties = new MessageProperties();
messageProperties.setContentType("application/json");
Message message = new Message(jsonObj.toString().getBytes(),messageProperties);
rabbitTemplate.convertAndSend("push_dispatch_**_exchange", "wxpush.msg.*", message); } } } }
3、创建交换机和队列
下载安装RabbitMQ参考：https://www.misboot.com/docs/bushuyunwei/RabbitMQ-anzhuang
创建交换机：push_dispatch_**_exchange和队列 push_dispatch_**_queue
关联交换机和队列 ，指定BindingKey ：wxpush.msg.*
4、接收方community 代码
启动类加注释 @EnableRabbit ，以及配置json转换器
接受消息，创建监听者
package cn.ewsd.community.utils;
import com.rabbitmq.client.Channel;
import org.springframework.amqp.rabbit.annotation.*;
import org.springframework.amqp.support.AmqpHeaders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.handler.annotation.Headers;
import org.springframework.messaging.handler.annotation.Payload;
import org.springframework.stereotype.Component;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;
@Component
public class wechaPushMsg {
@Autowired
private WeChatServiceImpl wechatServiceImpl;
@Autowired
private WxPustInfoMapper wxPustInfoMapper;
@RabbitListener(bindings = @QueueBinding(
value = @Queue(value = "push_dispatch_**_queue", durable = "true"),
exchange = @Exchange(
value = "push_dispatch_**_exchange",
durable = "true",
type = "direct",
ignoreDeclarationExceptions = "true"),
key = "wxpush.msg.*"
))
@RabbitHandler
public void processMessage(@Payload Map<String,Object> pushMsg, Channel channel, @Headers Map<String, Object> headers) throws IOException {
Long deliveryTag = (Long) headers.get(AmqpHeaders.DELIVERY_TAG);
System.out.println("接受到了push_dispatch_**_queue信息");
// 获取信息
try {
//调用消息推送方法
Map<String,Object> resultMap = wechatServiceImpl.pushOneUser(pushMsg);
if(resultMap.get("returncode").toString().equals("1")){
//2 记录已推送表
WxPustInfo wxPustInfo = new WxPustInfo();
String memo = "推送内容：" + data.toString();
//详细数据略过
wxPustInfo.setMemo(memo);
wxPustInfoMapper.insertSelective(wxPustInfo);
}
}catch (Exception e){
System.out.println("【信息存储失败】"+e.getMessage());
e.printStackTrace();
}
// 手工ack
channel.basicAck(deliveryTag,false);
}
}
5、遇到的问题
前期直接发送json字符串，一直报错：
Could not convert incoming message with content-type [text/plain], 'json' keyword missing
后在发送时指定格式后解决问题，代码如下：
参考文章：
https://www.cnblogs.com/sss4/p/16423718.html
https://www.bilibili.com/read/cv4081623
