解决ModelMapper在列表类型映射中的实例化问题

Failed to instantiate instance of destination java.util.List. Ensure that java.util.List has a non-private no-argument constructor.

public class VetClinic {
    private List<Doctor> doctors = new ArrayList<>(); // 关键：初始化为ArrayList
    // ... 其他属性和方法
}

public class VetClinicDto {
    private List<DoctorDto> doctorDtos = new ArrayList<>(); // 同样可以在DTO中初始化
    // ... 其他属性和方法
}

import org.modelmapper.ModelMapper;
import org.modelmapper.TypeMap;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class MappingConfig {

    public ModelMapper modelMapper() {
        ModelMapper mapper = new ModelMapper();

        // 为VetClinicDto到VetClinic的映射创建TypeMap
        TypeMap<VetClinicDto, VetClinic> typeMap = mapper.createTypeMap(VetClinicDto.class, VetClinic.class);

        // 定义如何映射doctorDtos到doctors
        typeMap.addMappings(mapping -> {
            mapping.using(context -> {
                // context.getSource() 是 VetClinicDto 对象
                // context.getDestination() 是 VetClinic 对象
                List<DoctorDto> doctorDtos = (List<DoctorDto>) context.getSource();
                if (doctorDtos == null) {
                    return null;
                }
                // 手动将 DoctorDto 列表映射到 Doctor 列表
                return doctorDtos.stream()
                        .map(doctorDto -> mapper.map(doctorDto, Doctor.class)) // 递归映射单个 DoctorDto
                        .collect(Collectors.toList());
            }).map(VetClinicDto::getDoctorDtos, VetClinic::setDoctors);
        });

        // 或者，如果你的自定义映射逻辑在 VetClinicDto 的子类中：
        // @Override
        // protected void mapSpecificFieldsToModelFromDto(VetClinicDto source, VetClinic destination) {
        //     if (source.getDoctorDtos() != null) {
        //         destination.setDoctors(source.getDoctorDtos().stream()
        //                 .map(doctorDto -> mapper.map(doctorDto, Doctor.class))
        //                 .toList()); // Java 16+
        //         // .collect(Collectors.toList()); // Java 8+
        //     } else {
        //         destination.setDoctors(new ArrayList<>()); // 确保目标列表不为null
        //     }
        // }

        return mapper;
    }
}

// DoctorMapper.java
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.factory.Mappers;

import java.util.List;

// 标记为Spring组件，如果你的项目使用Spring
@Mapper(componentModel = "spring")
public interface DoctorMapper {

    // 获取 MapStruct 生成的实例
    DoctorMapper INSTANCE = Mappers.getMapper(DoctorMapper.class);

    // 定义如何将 List<DoctorDto> 映射到 List<Doctor>
    List<Doctor> mapDoctorDtoListToDoctorList(List<DoctorDto> doctorDtos);

    // 定义如何将单个 DoctorDto 映射到 Doctor
    // 如果属性名相同，无需@Mapping注解
    Doctor mapDoctorDtoToDoctor(DoctorDto doctorDto);

    // 定义如何将 List<Doctor> 映射到 List<DoctorDto>
    List<DoctorDto> mapDoctorListToDoctorDtoList(List<Doctor> doctors);

    // 定义如何将单个 Doctor 映射到 DoctorDto
    DoctorDto mapDoctorToDoctorDto(Doctor doctor);
}

// VetClinicMapper.java
@Mapper(componentModel = "spring", uses = {DoctorMapper.class}) // 引用DoctorMapper
public interface VetClinicMapper {
    VetClinicMapper INSTANCE = Mappers.getMapper(VetClinicMapper.class);

    // 映射 VetClinicDto 到 VetClinic
    VetClinic mapToVetClinic(VetClinicDto vetClinicDto);

    // 映射 VetClinic 到 VetClinicDto
    VetClinicDto mapToVetClinicDto(VetClinic vetClinic);
}