RabbitMQ投递消息时确认机制Confirm和Return

最新推荐文章于 2022-09-27 17:33:44 发布

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#交换机 #队列 #rabbitmq

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本文介绍了RabbitMQ的消息确认(Confirm)和返回(Return)机制。通过开启Confirm模式并设置确认回调，当消息成功到达交换机时会触发handleAck方法，未成功则触发handleNack。若消息无法正确路由到队列，需配合监听器和参数设置为true来处理非正确路由的情况，确保消息不会丢失。

<dependencies>
    <dependency>
        <groupId>com.rabbitmq</groupId>
        <artifactId>amqp-client</artifactId>
        <version>5.10.0</version>
    </dependency>
</dependencies>

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.ConfirmListener;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class SendMessage {

    private final static String QUEUE_NAME = "test";

    private final static String ROUTE_KEY = QUEUE_NAME;

    private final static String MESSAGE = "I love three things in this world,the sun ,the moon and you.";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        {
            factory.setHost("49.232.202.201");
            factory.setUsername("gosuncn");
            factory.setPassword("123456");
            factory.setVirtualHost("/gosuncn");
        }
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        /**
         * 消息确认模式[confirm]
         */
        channel.confirmSelect();
        /**
         * 添加确认监听器
         */
        channel.addConfirmListener(new ConfirmListener() {
            //只要是交换机确认收到了消息就会回调ConfirmListener的handleAck方法。(即使交换机没有正确路由到队列中)
            @Override
            public void handleAck(long deliveryTag, boolean multiple) throws IOException {
                if (multiple) {
                    System.out.println("Before No." + deliveryTag + " have been confirmed.");
                } else {
                    System.out.println("No." + deliveryTag + " have been confirmed.");
                }
            }
            //只要是交换机没有确认收到了消息就会回调ConfirmListener的handleNack方法。
            @Override
            public void handleNack(long deliveryTag, boolean multiple) throws IOException {
                if (multiple) {
                    System.out.println("Before No." + deliveryTag + " have been not confirmed.");
                } else {
                    System.out.println("No." + deliveryTag + " have been not confirmed.");
                }
            }
        });
        /**
         * 如果消息到达了交换机且路由不可达那么回调ReturnListener的方法。
         * void basicPublish(String exchange, String routingKey, boolean mandatory, BasicProperties props, byte[] body)
         * 生效条件：第三个参数 mandatory 需要设置为true。
         */
        channel.addReturnListener((replyCode, replyText, exchange, routingKey, properties, body) -> {
            System.out.println(replyCode);
            System.out.println(replyText);
            System.out.println(exchange);
            System.out.println(routingKey);
        });
        /**
         * 发布消息
         */
        channel.basicPublish("", ROUTE_KEY, true, null, MESSAGE.getBytes());
        System.out.println("message delivery [" + MESSAGE + "]");
    }

}

第1步：开启confirm模式

channel.confirmSelect();

第2步：添加确认回调

void addConfirmListener(ConfirmListener listener);

public interface ConfirmListener {
    void handleAck(long deliveryTag, boolean multiple) throws IOException;

    void handleNack(long deliveryTag, boolean multiple) throws IOException;
}