CompanyMapperImpl.java

// When using @IterableMapping
...
  
    @Override
    public List<CompanyDTO> toDto(List<Company> company, Locale locale) {
        // NO call to @BeforeMethod
        if ( company == null ) {
            return null;
        }

        List<CompanyDTO> list = new ArrayList<CompanyDTO>( company.size() );
        for ( Company company1 : company ) {
            // here is using the method I need to be used, this is why I'm using @IterableMapping
            list.add( toDto( company1, locale ) );
        }

        return list;
    }
  
...
  
// But If I remove it:
  
...
  
    @Override
    public List<CompanyDTO> toDto(List<Company> company, Locale locale) {
        // Using the @Before method as expected
        List<CompanyDTO> target = fixLazyLoadingList( company );
        if ( target != null ) {
            return target;
        }

        if ( company == null ) {
            return null;
        }

        List<CompanyDTO> list = new ArrayList<CompanyDTO>( company.size() );
        for ( Company company1 : company ) {
            // here I'm missing the context param...
            list.add( toDto( company1 ) );
        }

        return list;
    }
  
...
  
  
  
  

Example.java

##############
# Some beans #
##############
public class Company {
    private String name;
    private List<Employee> employees;
    // getters and setters
}

public class CompanyDTO {
    private String name;
    private List<EmployeeDTO> employees;
    // getters and setters
}

public class Employee {
    private String name;
    //getters and setters
}
public class EmployeeDTO {
    private String name;
    //getters and setters
}

################
# Base Mappers #
################
public interface BaseMapper<T, E> extends SessionAwareMapping <T,E>{
    T toDto (E entity);

    E toEntity (T dto);

    @Named("toDtoLocale")
    T toDto(E entity, @Context Locale locale);

    @Named("toEntityLocale")
    E toEntity(T dto, @Context Locale locale);

    @Named("toDtoListLocale")
    List<T> toDto(List<E> entities, @Context Locale locale);

    @Named("toEntityListLocale")
    List<E> toEntity(List<T> dtos, @Context Locale locale);
}

public interface SessionAwareMapping <T,E> {

    @BeforeMapping
    default <T> List<T> fixLazyLoadingList(Collection<E> c) {
      // some logic here.
    }
}


################
# Mappers      #
################
@Mapper (componentModel = "spring", uses = {EmployeeMapper.class})
public interface CompanyMapper extends BaseMapper<CompanyDTO, Company>{
  
    @Named("toDtoLocale")
    @Mapping(target="employees", qualifiedByName = "toDtoListLocale")
    CompanyDTO toDto(Company company, @Context Locale locale);

    // If I remove below annotation, then the @BeforeMapping method is being used
    @IterableMapping(qualifiedByName = {"toDtoLocale"})
    List<CompanyDTO> toDto(List<Company> company, @Context Locale locale);
}

@Mapper(componentModel = "spring")
public interface EmployeeMapper extends BaseMapper<EmployeeDTO, Employee>{

    @Named("toDtoListLocale")
    @IterableMapping(qualifiedByName = "toDtoLocale")
    List<EmployeeDTO> toDto(List<Employee> entities, @Context Locale locale);
}