SpringBoot-RabbitMQ篇-消息可靠投递

一、发送者异常监控

1.1 发送者异常种类

1.基本处理流程

• 补偿(兜底)方案
  
  2.模拟broker宕机：修改发送者端口如5673，然后启动，发送消息，端口不对无法连接主机
• 错误信息：java.net.ConnectException: Connection timed out: connect
• 补偿方案：加入异常处理，如果不可达则返回错误
• 这种错误在发送的时候就已经可以发现，直接将错误返回给调用方即可

@RequestMapping("/direct")
public Object sendEmail(String msg) {
    try {
        rabbitTemplate.convertAndSend("exchange.direct.springboot.email", "queue.email.routing.key", msg);
        return msg;
    } catch (AmqpException e) {
        System.out.println("发送出现异常：" + e.getMessage());
        return "网络中断，请稍后再试";
    }
}

3.模拟无交换器异常

• 错误信息

ERROR 4880 — [.200.57.39:5672] o.s.a.r.c.CachingConnectionFactory : Channel shutdown: channel error; protocol method: #method(reply-code=404, reply-text=NOT_FOUND - no exchange ‘noExchange’ in vhost ‘/’, class-id=60, method-id=40)

• 错误说明：如果没有交换器并不会报错，只会输出一条日志
• 补偿方案：需要采用发送回调来确认是否成功发送消息

4.模拟无路由异常

• 错误信息：无任何提示，消息直接被丢弃
• 补偿方案：需要采用发送回调来确认是否成功发送消息

1.2 消息发送回调

1. 因为消息是异步发送，所以需要确保消息能正确发送
2. 所以可配置RabbitTemplate然后指定回调信息
3. 步骤01：修改配置文件，配置回调参数

publisher-confirm-type

• org.springframework.boot.autoconfigure.amqp.RabbitProperties#publisherConfirmType
• org.springframework.amqp.rabbit.connection.CachingConnectionFactory.ConfirmType

spring:
  rabbitmq:
    host: 127.0.0.1
    port: 5672
    username: tianxin
    password: tianxin
    # 开启消息发broker回调
    publisher-confirm-type: correlated
    # 开启路由消息路由回调
    publisher-returns: true
    # 强制确认，也可以在代码中开启
    template:
      mandatory: true

/**
 * The type of publisher confirms to use.
 */
public enum ConfirmType {

	/**
	 * Use {@code RabbitTemplate#waitForConfirms()} (or {@code waitForConfirmsOrDie()}
	 * within scoped operations.
	 */
	SIMPLE,

	/**
	 * Use with {@code CorrelationData} to correlate confirmations with sent
	 * messsages.
	 */
	CORRELATED,

	/**
	 * Publisher confirms are disabled (default).
	 */
	NONE
}

4.步骤02：配置RabbitTemplate，设置交换器确认回调和路由回调
setConfirmCallback：无论成功与否都会调用
setReturnCallback：错误时才调用

import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.Objects;

@Configuration
public class CustomRabbitTemplate {

    @Bean
    public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
        RabbitTemplate rabbitTemplate = new RabbitTemplate();
        // 开启mandatory为true才能触发回调方法，无论消息推送结果如何强制调用回调方法
        rabbitTemplate.setMandatory(true);
        // 设置连接工厂信息
        rabbitTemplate.setConnectionFactory(connectionFactory);

        // 消息发broker回调：发送者到broker的exchange是否正确找到
        rabbitTemplate.setConfirmCallback((correlationData, ack, cause) -> {
            System.out.println("setConfirmCallback 消息数据：" + correlationData);
            if (Objects.nonNull(correlationData)) {
                System.out.println("setConfirmCallback 消息数据：" + correlationData.getReturnedMessage());
            }
            System.out.println("setConfirmCallback 消息确认：" + ack);
            System.out.println("setConfirmCallback 原因：" + cause);
            System.out.println("-----------------------------------");
        });

        // 消息路由回调：从交换器路由到队列是否正确发送
        rabbitTemplate.setReturnCallback((message, replyCode, replyText, exchange, routingKey) -> {
            System.out.println("setReturnCallback 消息：" + message);
            System.out.println("setReturnCallback 回应码：" + replyCode);
            System.out.println("setReturnCallback 回应信息：" + replyText);
            System.out.println("setReturnCallback 交换器：" + exchange);
            System.out.println("setReturnCallback 路由键：" + routingKey);
            System.out.println("-----------------------------------");
        });

        return rabbitTemplate;
    }
}

• 路由回调和消息回调

/**
 * A callback for publisher confirmations.
 *
 */
@FunctionalInterface
public interface ConfirmCallback {

	/**
	 * Confirmation callback.
	 * @param correlationData correlation