public String generateMessageId(String messageBody) {
    return DigestUtils.md5DigestAsHex(messageBody.getBytes(StandardCharsets.UTF_8));
}

@Autowired
private StringRedisTemplate redisTemplate;

public boolean isDuplicateMessage(String messageId) {
    Boolean exists = redisTemplate.hasKey(messageId);
    return Boolean.TRUE.equals(exists);
}

public void markMessageAsProcessed(String messageId) {
    redisTemplate.opsForValue().set(messageId, "processed", 1, TimeUnit.DAYS);
}

import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.support.MessageProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

@Service
public class RabbitMQConsumer {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @RabbitListener(queues = "task_queue")
    public void receiveMessage(String message, MessageProperties messageProperties) {
        String messageId = messageProperties.getMessageId();
        
        // 如果消息沒有ID，則自行生成一個ID（假設(shè)消息內(nèi)容不變）
        if (messageId == null || messageId.isEmpty()) {
            messageId = generateMessageId(message);
        }

        // 檢查消息是否已經(jīng)處理過
        if (isDuplicateMessage(messageId)) {
            System.out.println("Message with ID " + messageId + " already processed, skipping.");
            return;
        }

        try {
            // 處理消息的業(yè)務(wù)邏輯
            processMessage(message);

            // 處理成功后，標(biāo)記消息ID
            markMessageAsProcessed(messageId);

        } catch (Exception e) {
            System.err.println("Failed to process message with ID " + messageId + ": " + e.getMessage());
            // 如果處理失敗，可以根據(jù)業(yè)務(wù)需求選擇是否重新投遞消息
        }
    }

    private void processMessage(String message) {
        // 具體的消息處理邏輯
        System.out.println("Processing message: " + message);
        // 假設(shè)處理邏輯是冪等的
    }

    private String generateMessageId(String messageBody) {
        return DigestUtils.md5DigestAsHex(messageBody.getBytes(StandardCharsets.UTF_8));
    }

    private boolean isDuplicateMessage(String messageId) {
        Boolean exists = redisTemplate.hasKey(messageId);
        return Boolean.TRUE.equals(exists);
    }

    private void markMessageAsProcessed(String messageId) {
        redisTemplate.opsForValue().set(messageId, "processed", 1, TimeUnit.DAYS);
    }
}