上篇文章咱们简单的介绍了stream的使用,发现使用仍是蛮方便的,可是在上个案例中,若是有多个消息接收者,那么消息生产者发送的消息会被多个消费者都接收到,这种状况在某些实际场景下是有很大问题的,好比在以下场景中,订单系统咱们作集群部署,都会从RabbitMQ中获取订单信息,那若是一个订单同时被两个服务获取到,那么就会形成数据错误,咱们得避免这种状况。这时咱们就可使用Stream中的消息分组来解决了!java
消息分组的做用咱们已经介绍了。注意在Stream中处于同一个group中的多个消费者是竞争关系。就可以保证消息只会被其中一个应用消费一次。不一样的组是能够消费的,同一个组内会发生竞争关系,只有其中一个能够消费。经过案例咱们来演示看看,这里咱们会建立3个服务,分别以下
|服务|介绍 |
|--|:--|
| stream-group-sender |消息发送者服务 |
| stream-group-receiverA|消息接收者服务 |
|stream-group-receiverB | 消息接收者服务 |git
<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 http://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>1.5.13.RELEASE</version> </parent> <groupId>com.bobo</groupId> <artifactId>stream-group-sender</artifactId> <version>0.0.1-SNAPSHOT</version> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Dalston.SR5</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-stream-rabbit</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
配置中的“outputProduct”能够自定义,可是咱们等会在消息接口中要使用到。github
spring.application.name=stream-sender server.port=9060 #设置服务注册中心地址,指向另外一个注册中心 eureka.client.serviceUrl.defaultZone=http://dpb:123456@eureka1:8761/eureka/,http://dpb:123456@eureka2:8761/eureka/ #rebbitmq 连接信息 spring.rabbitmq.host=192.168.88.150 spring.rabbitmq.port=5672 spring.rabbitmq.username=dpb spring.rabbitmq.password=123 spring.rabbitmq.virtualHost=/ # 对应 MQ 是 exchange outputProduct自定义的信息 spring.cloud.stream.bindings.outputProduct.destination=exchangeProduct
/** * 发送消息的接口 * @author dengp * */ public interface ISendeService { String OUTPUT="outputProduct"; /** * 指定输出的交换器名称 * @return */ @Output(OUTPUT) SubscribableChannel send(); }
@SpringBootApplication @EnableEurekaClient // 绑定咱们刚刚建立的发送消息的接口类型 @EnableBinding(value={ISendeService.class}) public class StreamSenderStart { public static void main(String[] args) { SpringApplication.run(StreamSenderStart.class, args); } }
在本案例中咱们发送的消息是自定义的对象web
package com.bobo.stream.pojo; import java.io.Serializable; public class Product implements Serializable{ private Integer id; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Product(Integer id, String name) { super(); this.id = id; this.name = name; } public Product() { super(); } @Override public String toString() { return "Product [id=" + id + ", name=" + name + "]"; } }
<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 http://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>1.5.13.RELEASE</version> </parent> <groupId>com.bobo</groupId> <artifactId>stream-group-receiverA</artifactId> <version>0.0.1-SNAPSHOT</version> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Dalston.SR5</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-stream-rabbit</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
配置文件中配置分组“groupProduct”spring
spring.application.name=stream-group-receiverA server.port=9070 #设置服务注册中心地址,指向另外一个注册中心 eureka.client.serviceUrl.defaultZone=http://dpb:123456@eureka1:8761/eureka/,http://dpb:123456@eureka2:8761/eureka/ #rebbitmq 连接信息 spring.rabbitmq.host=192.168.88.150 spring.rabbitmq.port=5672 spring.rabbitmq.username=dpb spring.rabbitmq.password=123 spring.rabbitmq.virtualHost=/ # 对应 MQ 是 exchange 和消息发送者的 交换器是同一个 spring.cloud.stream.bindings.inputProduct.destination=exchangeProduct # 具体分组 对应 MQ 是 队列名称 而且持久化队列 inputProduct 自定义 spring.cloud.stream.bindings.inputProduct.group=groupProduct
/** * 接收消息的接口 * @author dengp * */ public interface IReceiverService { String INPUT = "inputProduct"; /** * 指定接收的交换器名称 * @return */ @Input(INPUT) SubscribableChannel receiver(); }
/** * 具体接收消息的处理类 * @author dengp * */ @Service @EnableBinding(IReceiverService.class) public class ReceiverService { @StreamListener(IReceiverService.INPUT) public void onReceiver(Product p){ System.out.println("消费者A:"+p); } }
注意一样须要添加Product类apache
package com.bobo.stream.pojo; import java.io.Serializable; public class Product implements Serializable{ private Integer id; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Product(Integer id, String name) { super(); this.id = id; this.name = name; } public Product() { super(); } @Override public String toString() { return "Product [id=" + id + ", name=" + name + "]"; } }
@SpringBootApplication @EnableEurekaClient @EnableBinding(value={IReceiverService.class}) public class StreamReceiverStart { public static void main(String[] args) { SpringApplication.run(StreamReceiverStart.class, args); } }
此服务和stream-group-receiverA同样,复制一份只需修改application.properties中的服务名称,端口。咱们先将group设置不同,咱们测试来看看app
spring.application.name=stream-group-receiverB server.port=9071 #设置服务注册中心地址,指向另外一个注册中心 eureka.client.serviceUrl.defaultZone=http://dpb:123456@eureka1:8761/eureka/,http://dpb:123456@eureka2:8761/eureka/ #rebbitmq 连接信息 spring.rabbitmq.host=192.168.88.150 spring.rabbitmq.port=5672 spring.rabbitmq.username=dpb spring.rabbitmq.password=123 spring.rabbitmq.virtualHost=/ # 对应 MQ 是 exchange 和消息发送者的 交换器是同一个 spring.cloud.stream.bindings.inputProduct.destination=exchangeProduct # 具体分组 对应 MQ 是 队列名称 而且持久化队列 inputProduct 自定义 spring.cloud.stream.bindings.inputProduct.group=groupProduct1
@RunWith(SpringRunner.class) @SpringBootTest(classes=StreamSenderStart.class) public class StreamTest { @Autowired private ISendeService sendService; @Test public void testStream(){ Product p = new Product(666, "stream test ..."); // 将须要发送的消息封装为Message对象 Message message = MessageBuilder .withPayload(p) .build(); sendService.send().send(message ); } }
在stream-group-receiverA和stream-group-receiverB服务的group不一致的状况下maven
改成同组的状况下ide
启动服务,发送数据spring-boot
经过结果能够看到只有其中一个受到消息。避免了消息重复消费。
案例代码github:https://github.com/q279583842q/springcloud-e-book