@SuppressWarnings("unchecked")
    private Object doConvertMessage(MessageExt messageExt) {
        if (Objects.equals(messageType, MessageExt.class) || Objects.equals(messageType, org.apache.rocketmq.common.message.Message.class)) {
            return messageExt;
        } else {
            String str = new String(messageExt.getBody(), Charset.forName(charset));
            if (Objects.equals(messageType, String.class)) {
                return str;
            } else {
                // If msgType not string, use objectMapper change it.
                try {
                    if (messageType instanceof Class) {
                        //if the messageType has not Generic Parameter
                        return this.getMessageConverter().fromMessage(MessageBuilder.withPayload(str).build(), (Class<?>) messageType);
                    } else {
                        //if the messageType has Generic Parameter, then use SmartMessageConverter#fromMessage with third parameter "conversionHint".
                        //we have validate the MessageConverter is SmartMessageConverter in this#getMethodParameter.
                        return ((SmartMessageConverter) this.getMessageConverter()).fromMessage(MessageBuilder.withPayload(str).build(), (Class<?>) ((ParameterizedType) messageType).getRawType(), methodParameter);
                    }
                } catch (Exception e) {
                    log.info("convert failed. str:{}, msgType:{}", str, messageType);
                    throw new RuntimeException("cannot convert message to " + messageType, e);
                }
            }
        }
    }
Message consume retry strategy in concurrently mode.

-1,no retry,put into DLQ directly
0,broker control retry frequency
>0,client control retry frequency
rocketmq-spring-boot/src/main/java/org/apache/rocketmq/spring/support/DefaultRocketMQListenerContainer.java