mapstruct native support protobuf

Use case

The reasons are as follows:

1. gRPC use protobuf ,Jakarta EE 10 choise gRPC as Jakarta RPC , . Net Core same choise gRPC.

2. It is a good idea in the near future that protobuf will be selected as the data exchange foundation of heterogeneous platforms for service mash of microservice architecture.

3. MapStruct is not friendly to protobuf. For a long time, it will inevitably generate new components instead of building on the MapStruct foundation. It may introduce technologies similar to ByteBuf to improve the copy efficiency.

4. No configuration is better than complex configuration. Most people choose MapStruct not to learn complex configuration, but to improve efficiency. In complex scenarios, customers write code instead of configuring MapStruct, which seems to go further and further. What is the original intention of the project? Is the goal of the project to solve complex situations through configuration?

I look forward to your reply!

Generated Code

Bean Map copy to Protobuf Map putAll Error : UnsupportedOperationException.
correct：
basicTestMessageMap.putAllTestStrMap(map);
replace
basicTestMessageMap.getTestStrMap().putAll( map );

    @Override
    public BasicTestMessageMap toMap(BasicTestBeanMap beanMap) {
        if ( beanMap == null ) {
            return null;
        }

        BasicTestMessageMap.Builder basicTestMessageMap = BasicTestMessageMap.newBuilder();

        if ( basicTestMessageMap.getTestStrMap() != null ) {
            Map<String, String> map = beanMap.getTestStrMap();
            if ( map != null ) {
                basicTestMessageMap.getTestStrMap().putAll( map );
            }
        }

        return basicTestMessageMap.build();
    }

Possible workarounds

No response

MapStruct Version

1.5.3.Final

まず、生成された BasicTestMessageMap mapper に示されている protobuf map mapping を再現し、getter ベースの putAll 呼び出しで発生する UnsupportedOperationException を確認します。生成されたコードを要求された builder map operation と比較します。protobuf map mappings がその例外なしで動作し、意図した生成動作が regression test でカバーされれば完了です。