kafka stream 没有从平面 map 值向 dlq 主题生成消息

Question

valid.flatMapValues(v -> {
            long start = System.currentTimeMillis();
            try {
                List<JsonNode> result = Collections.singletonList(validmethods(v));
                long end = System.currentTimeMillis();
                logger.info("Time taken to process :: " + (end - start));
                return result;
            } catch (Exception e) {
                SendToDeadLetterQueueExceptionHandler.sendtotopic(new ProducerRecord<String,String>(KafkaConstants.deadLetterTopic,e.getCause().toString()));
                logger.error("Exception in stream topology", e);
            }
            long end = System.currentTimeMillis();
            logger.info("Time taken to process (errored out) :: " + (end - start));
            return Collections.emptyList();
        }).to(KafkaConstants.targetTopic, Produced.with(Serdes.String(), producerserde()));

它会关闭 kafka stream 以防有效方法（v）中出现异常。但是，如果我停止从 catch 块生成 dlq 主题，它工作正常。