Java确保MQ消息队列不丢失的实现与流程分析

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

public class Producer {
    private static final String QUEUE_NAME = "test_queue";

    public static void main(String[] args) throws Exception {
        // 创建连接工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setUsername("guest");
        factory.setPassword("guest");

        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {

            // 声明队列，设置持久化
            boolean durable = true; // 持久化队列
            channel.queueDeclare(QUEUE_NAME, durable, false, false, null);

            String message = "Hello, RabbitMQ!";
            // 发送消息，设置持久化
            channel.basicPublish("", QUEUE_NAME, 
                MessageProperties.PERSISTENT_TEXT_PLAIN, message.getBytes());
            System.out.println(" [x] Sent '" + message + "'");
        }
    }
}

import com.rabbitmq.client.*;

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

public class Consumer {
    private static final String QUEUE_NAME = "test_queue";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setUsername("guest");
        factory.setPassword("guest");

        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // 声明队列，确保与生产者一致
        boolean durable = true;
        channel.queueDeclare(QUEUE_NAME, durable, false, false, null);

        // 设置手动确认模式
        channel.basicQos(1); // 每次只接收一条消息
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            try {
                // 模拟消息处理
                System.out.println(" [x] Received '" + message + "'");
                doWork(message);
            } finally {
                // 手动确认消息
                channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
                System.out.println(" [x] Done");
            }
        };

        // 开始消费
        channel.basicConsume(QUEUE_NAME, false, deliverCallback, consumerTag -> {});
    }

    private static void doWork(String task) {
        try {
            Thread.sleep(1000); // 模拟任务处理时间
        } catch (InterruptedException _ignored) {
            Thread.currentThread().interrupt();
        }
    }
}