The RocketMQListener can not deserialize generic onMessage method parameter

[caimofei]

Problems:
When definition the listener like this. the starter cannot settup
public class Listener1 implements RocketMQListener<MsgDto<String>>

Recently, I tryied solve this problem,only modify the DefaultRocketMQListenerContainer class. Wish to improve the starter in next release.

1. My Main idea is use org.springframework.messaging.converter.SmartMessageConverter#fromMessage .This interface define a third parameter called "Object conversionHint".
2. I switch the Definition of DefaultRocketMQListenerContainer#messageType to Type insteadof Class
3. add a "private MethodParameter onMessageParameter" member to DefaultRocketMQListenerContainer and init it to indicate the onMessage parameter when afterPropertiesSet()
4. when doCovertMessage. if the messageType instanceof ParameterizedType, then call fromMessage with the third parameter(methodParameter). The MappingJackson2MessageConverter can use it to deserialization the message.

[RongtongJin]

@caimofei , good catch! Could you submit a PR to fix this issue?

[caimofei]

@caimofei , good catch! Could you submit a PR to fix this issue?

i have make a pr #201

[RongtongJin]

@caimofei OK, I will reivew the pr ASAP.