Consumer batch messages API.

[ruoshuixuelabi]

请问怎么批量的接收消息，比如按照文档接收消息是这样的 @Slf4j @Service @RocketMQMessageListener(topic = "test-topic-2", consumerGroup = "my-consumer_test-topic-2") public class MyConsumer implements RocketMQListener<OrderPaidEvent> { @Override public void onMessage(OrderPaidEvent orderPaidEvent) { log.info("received orderPaidEvent: {}", orderPaidEvent); } } 我现在想把里面的OrderPaidEvent orderPaidEvent变成List<OrderPaidEvent> orderPaidEvent这样的，我测试了一下这样会报错，原生的是支持批量的，现在我看了一遍源码没有找到批量接收的方法

[RongtongJin]

It is not supported yet.

[liuanxin]

为什么在 2.1.0 里面又删除了呢?

[liuliuzo]

是这样的我们这里也有批量消费的需求，主要是想结合ORM的批量提交增加性能 ，由于能力有限,，能想到的方式很不优雅，support native listener #293 ，然后在native listener自己处理批量。希望rocketmq-spring能提供批量消费这个功能。

[wz2cool]

We also meet the same problem, this feature is important for us to batch save data to database.

[zdy333666]

yes，we need batch consumer .

[wz2cool]

Currently, I found a workaround to get batch messages. But we still perfer batch listener

@RocketMQMessageListener(topic = "demo_product", consumerGroup = "demo_batch_product_consumerGroup", consumeMode = ConsumeMode.ORDERLY)
public class ProductBatchConsumer implements RocketMQListener<String>, RocketMQPushConsumerLifecycleListener {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public void onMessage(String message) {
        // do noting, have to implement RocketMQListener or throw error
    }

    private AtomicInteger atomicInteger = new AtomicInteger();

    @Override
    public void prepareStart(DefaultMQPushConsumer consumer) {
        consumer.setPullInterval(1000);
        consumer.setConsumeThreadMin(1);
        consumer.setConsumeThreadMax(1);
        consumer.setConsumeMessageBatchMaxSize(1000);
        consumer.setPullBatchSize(100);
        consumer.registerMessageListener((MessageListenerConcurrently) (msgs, context) -> {
            System.out.println("batchSize: " + msgs.size());
            int result = atomicInteger.addAndGet(msgs.size());
            System.out.println("totalSize: " + result);
            return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
        });
    }
}

[wz2cool]

@RongtongJin Any update about this issue ? I found an PR #170 about batch listener

[nidonglin]

we need batch consumer .

[nidonglin]

It is not supported yet.

why?

[ShawshankLin]

使用pull模式的List<String> messages = rocketMQTemplate.receive(String.class)是否就可以获取批量数据？

[771917534]

we need batch consumer

[superleo-cn]

rocketMQTemplate.receive 后，是否需要手工调用下面的代码来提交ack呢？

rocketMQTemplate.getConsumer().commitSync();

[pupilming]

DefaultRocketMQListenerContainer 这个地方能否直接支持把原始的List<MessageExt> msgs传递下去呢，很多场景都需要批量的数据处理提升性能