rabbitmq 解决重复消费 保证消息的幂等性

很简单, 我们在生产者生产消息的时候, 都要给消息加一个messageId作为消息的唯一值, 就是为了消费方避免重复消费

    @RabbitListener(queues = ORDER_SUBMIT)
    @RabbitHandler
    @Transactional
    public void orderSubmitHandler(@Payload Map<Object, Object> map, Message message, Channel channel) throws IOException {
        Object order = map.get("messageData");
        String messageId = (String) map.get("messageId");
        Object exist = redisUtils.get(messageId);
        if (null != exist) {
            // 丢弃消息至死信队列
            channel.basicReject(message.getMessageProperties().getDeliveryTag(), false);
            return;
        }
            
        // 业务代码
    }

开启手动确认消息

channel.basicAck(message.getMessageProperties().getDeliveryTag(), false); //手动确认消息

channel.basicReject(message.getMessageProperties().getDeliveryTag(), false); //拒绝消息 false 拒绝消息重新排队

    /**
     * Reject a message. Supply the deliveryTag from the {@link com.rabbitmq.client.AMQP.Basic.GetOk}
     * or {@link com.rabbitmq.client.AMQP.Basic.Deliver} method
     * containing the received message being rejected.
     * @see com.rabbitmq.client.AMQP.Basic.Reject
     * @param deliveryTag the tag from the received {@link com.rabbitmq.client.AMQP.Basic.GetOk} or {@link com.rabbitmq.client.AMQP.Basic.Deliver}
     * @param requeue true if the rejected message should be requeued rather than discarded/dead-lettered
     * @throws java.io.IOException if an error is encountered
     */
    void basicReject(long deliveryTag, boolean requeue) throws IOException;

RabbitMQ 配置死信队列