如何为 Mapstruct 指定默认映射方法

Question

I have simple object Client

public class Client {
    String externalCode;
    String name;
    String surname;
}

And I want to map it to nearly identical object

public class User {
    String internalCode;
    String name;
    String surname;
}

See, I want externalCode to be mapped to internalCode. And I have a method which does that. I have marker my method with my custom @CodeMapping annotation and put that annotation to qualifiedBy parameter. So, here is my mapper.

@Mapper()
ClientMapper {
     @CodeMapping
     String toInternalCode(String externalCode) {
          return externalCode + " internal part";
     }

    @Mapping(target = "internalCode", source = "externalCode", qualifiedBy = CodeMapping.class)
    User toUser(Client client);
}

The problem is that name and surname fields are also mapped using toInternalCode method. Mapstruct sees that I have defined a method, which maps String to String and thinks it should be used in all cases.

Is there a way to tell Mapstruct, that if no qualifiers are specified, direct mapping should be used? Or make my own method which takes string and return it and tell Mapstruct it should use that method by default?

Answer 1

Most likely the toInternalCode is used by all methods because the @CodeMapping annotation is not meta annotated with @Qualifier (from org.mapstruct.Qualifier ).

The @CodeMapping should be defined in the following way:

import org.mapstruct.Qualifier;

@Qualifier
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.CLASS)
public @interface CodeMapping {
}