Spring Cloud Stream 4.0.4 rabbitmq sends message multi-function

Create a Springboot project using idea

Add Spring cloud stream and rabbitmq dependencies

pom file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springcloudstream-demo1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springcloudstream-demo1</name>
    <description>springcloudstream-demo1</description>
    <properties>
        <java.version>17</java.version>
        <spring-cloud.version>2023.0.0-RC1</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
<!--        <dependency>-->
<!--            <groupId>org.springframework.boot</groupId>-->
<!--            <artifactId>spring-boot-starter-web</artifactId>-->
<!--        </dependency>-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-stream</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-stream-binder-rabbit</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.amqp</groupId>
            <artifactId>spring-rabbit-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-stream-test-binder</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

</project>

Modify configuration file

--- # rabbitmq 消费者配置
spring:
  rabbitmq:
    host: localhost
    port: 5672
    username: ruoyi
    password: ruoyi123
  cloud:
    stream:
      rabbit:
        bindings:
          demo2-in-0:
            consumer:
              delayed-exchange: true
      bindings:
        demo-in-0:
          content-type: application/json
          destination: demo-destination
          group: demo-group
          binder: rabbit
        demo1-in-0:
          content-type: application/json
          destination: demo1-destination
          group: demo1-group
          binder: rabbit
        demo2-in-0:
          content-type: application/json
          destination: demo2-destination
          group: demo2-group
          binder: rabbit
    function:
      definition: demo;demo1;demo2

Create consumer

package com.example.springcloudstreamdemo1;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import java.util.function.Consumer;

@SpringBootApplication
public class SpringcloudstreamDemo1Application {

    public static void main(String[] args) {
        SpringApplication.run(SpringcloudstreamDemo1Application.class, args);
    }
 	 /**
     * 注意方法名称 demo 要与配置文件中的spring.cloud.stream.bindings.demo-in-0 保持一致
     * 其中 -in-0 是固定写法，in 标识消费者类型，0是消费者索引
     */
    @Bean
    public Consumer<Person> demo() {
        return person -> {
            System.out.println("Received: " + person);
        };
    }
    @Bean
    public Consumer<String> demo1() {
        return msg -> {
            System.out.println("Received: " + msg);
        };
    }
    @Bean
    public Consumer<Person> demo2() {
        return msg -> {
            System.out.println("Received: " + msg);
        };
    }

    public static class Person {
        private String name;
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String toString() {
            return this.name;
        }
    }
}

Note that when there are multiple consumers, you need to add configuration items: spring.cloud.function.definition

Startup project

Startup log

View the mq console

switch information

The switch name corresponds to:
The value of the spring.cloud.stream.bindings.demo-in-0.destination configuration item

Queue information

• The queue name is the switch name + group name

Add producer configuration

--- #生产者配置
spring:
  cloud:
    stream:
      rabbit:
        bindings:
          demo2-out-0:
            producer:
              delayedExchange: true #设置为延迟队列
      bindings:
        demo-out-0:
          content-type: application/json
          destination: demo-destination  # 同消费者保持一致
          binder: rabbit
        demo1-out-0:
          content-type: application/json
          destination: demo1-destination
          binder: rabbit
        demo2-out-0:
          content-type: application/json
          destination: demo2-destination
          binder: rabbit

Create message producer

package com.example.springcloudstreamdemo1;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.stream.function.StreamBridge;
import org.springframework.messaging.Message;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class ProducerController
{
    @Autowired
    private StreamBridge streamBridge;


    @GetMapping("sendMsg")
    public String sendMsg(int delay, String name){

        //delay 延时时间毫秒
        SpringcloudstreamDemo1Application.Person person = new SpringcloudstreamDemo1Application.Person();
        person.setName(name);
        Message<SpringcloudstreamDemo1Application.Person> message = MessageBuilder.withPayload(person)
                .setHeader("x-delay", delay).build();
        // 发送延时消息
        streamBridge.send("demo2-out-0", message);

        streamBridge.send("demo1-out-0", person);

        streamBridge.send("demo-out-0", person);

        return "发送成功";
    }
}

Start testing

Send a message

http://localhost:8080/sendMsg?delay=10000&name=zhangsan

Print message

conclusion of issue

Question one

Multiple functional beans were found [*,*], thus can't determine default function definition. Please use 'spring.cloud.function.definition' property to explicitly define it.

Solution:
Check whether the configuration is correct:
spring.cloud.function.definition