1、应答模式
NONE
可以称之为自动回调，即使无响应或者发生异常均会通知队列消费成功，会丢失数据。
AUTO
自动检测异常或者超时事件，如果发生则返回noack，消息自动回到队尾，但是这种方式可能出现消息体本身有问题，返回队尾其他队列也不能消费，造成队列阻塞。
MANUAL
手动回调，在程序中我们可以对消息异常记性捕获，如果出现消息体格式错误问题，手动回复ack，接着再次调用发送接口把消息推到队尾。
2、java示例
2.1 pom.xml
<dependencies>
<!-- spring boot -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>
</dependencies>
2.2 配置文件application.yml
spring:
application:
name: rabbitmq
rabbitmq:
host: 127.0.0.1
port: 5672
username: admin
password: pwd
listener:
simple:
retry:
enabled: true #是否开启消费者重试（为false时关闭消费者重试，这时消费端代码异常会一直重复收到消息）
max-attempts: 5 #最大重试次数
initial-interval: 5000 #重试间隔时间（单位毫秒）
max-interval: 1200000 #重试最大时间间隔（单位毫秒）
multiplier: 5 #应用于前一重试间隔的乘法器。
2.3 配置类
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
* @ClassName: TopicRabbitConfig
* @Description:
* @author weiyb
* @date 2018年2月26日 下午4:38:16
*/
@Configuration
public class TopicRabbitConfig {
public final static String QUEUE_NAME = "spring-boot-queue";
public final static String EXCHANGE_NAME = "spring-boot-exchange";
public final static String ROUTING_KEY = "spring-boot-key";
/**
* 创建队列
* @return
* @author weiyb
*/
@Bean("queueMessage")
public Queue queueMessage() {
return new Queue(QUEUE_NAME);
}
/**
* 创建一个 topic 类型的交换器
* @return
* @author weiyb
*/
@Bean("exchange")
TopicExchange exchange() {
return new TopicExchange(EXCHANGE_NAME);
}
/**
* 使用路由键（routingKey）把队列（Queue）绑定到交换器（Exchange）
* @param queueMessage
* @param exchange
* @return
* @author weiyb
*/
@Bean
Binding bindingExchangeMessage(@Qualifier("queueMessage") Queue queueMessage,@Qualifier("exchange") TopicExchange exchange) {
return BindingBuilder.bind(queueMessage).to(exchange).with(ROUTING_KEY);
}
}
2.4 消费者（监听）
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSON;
import com.spring.pro.config.exchange.TopicRabbitConfig;
import com.spring.pro.config.exchange.transaction.TopicRabbitConfigTransaction;
import com.spring.pro.model.User;
@Component
public class HelloReceiver {
private Logger logger = LoggerFactory.getLogger(getClass());
@RabbitListener(queues = TopicRabbitConfig.QUEUE_NAME)
public void process11(User user) {
logger.info("Receiver process11: " + JSON.toJSONString(user));
// 这里抛出异常,测试消息重发机制
// throw new RuntimeException("***********");
}
}
2.5 model
import java.io.Serializable;
/**
* @Title: User.java
* @Package com.spring.pro.model
* @Description:
* @author ybwei
* @date 2018年11月22日 下午2:46:10
* @version V1.0
*/
public class User implements Serializable {
private static final long serialVersionUID = 337531670671807745L;
private String id;
private String name;
private int age;
public User() {
super();
}
public User(String id, String name, int age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
2.6 生产者
import java.util.Date;
import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.spring.pro.config.exchange.TopicRabbitConfig;
import com.spring.pro.model.User;
@Component
public class HelloSender {
@Autowired
private AmqpTemplate rabbitTemplate;
public void send1() {
User user=new User("1", "张三", 12);
this.rabbitTemplate.convertAndSend(TopicRabbitConfig.EXCHANGE_NAME, TopicRabbitConfig.ROUTING_KEY, user);
}
}
2.7 测试
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import com.spring.pro.send.HelloSender;
@RunWith(SpringRunner.class)
@SpringBootTest
public class RabbitMqHelloTest {
@Autowired
private HelloSender helloSender;
@Test
public void hello1() throws Exception {
helloSender.send1();
}
}
3、应用场景
- 常用的mq通信。
- 上游向下游回调通知策略。配置文件中的max-attempts（最大重试次数），multiplier（应用于前一重试间隔的乘法器）可以制定策略。
测试重试，第二种方式的日志如下：
[INFO ] 2018-11-22 18:03:51.853 [SimpleAsyncTaskExecutor-1] c.spring.pro.receiver.HelloReceiver - Receiver process11: {"age":12,"id":"1","name":"张三"}
[INFO ] 2018-11-22 18:03:56.881 [SimpleAsyncTaskExecutor-1] c.spring.pro.receiver.HelloReceiver - Receiver process11: {"age":12,"id":"1","name":"张三"}
[INFO ] 2018-11-22 18:04:21.893 [SimpleAsyncTaskExecutor-1] c.spring.pro.receiver.HelloReceiver - Receiver process11: {"age":12,"id":"1","name":"张三"}
[INFO ] 2018-11-22 18:06:26.907 [SimpleAsyncTaskExecutor-1] c.spring.pro.receiver.HelloReceiver - Receiver process11: {"age":12,"id":"1","name":"张三"}
当前时间间隔=上次重试间隔*multiplier。
当前时间间隔<max-interval（重试最大时间间隔）。
