如何将 MapStruct 用于不同的数据类型？

Question

我有两种类型的数据要映射：注册用户Dto：public class SignUpUserDto {    private String firstName;    private String lastName;    private String username;    private String email;    private String password;    private String title;}注册用户：@Entitypublic class SignUpUser {    private Long id;    private String firstName;    private String lastName;    private String username;    private String email;    private String password;    private Title title;}标题：public enum Title {    JUNIOR("junior"),    MIDDLE("middle"),    SENIOR("senior"),    MANAGER("manager");    private final String title;    Title(final String title) {        this.title = title;    }    public String toString() {        return this.title;    }}对于DTO title 成员是一个String。对于实体title 成员是Title。映射器应该是什么样子的？我应该传递已经在服务中转换的标题吗？@Mapper(componentModel = "spring")public interface SignUpUserMapper {    SignUpUserMapper INSTANCE = Mappers.getMapper(SignUpUserMapper.class);    @Mapping(target = "title", expression = "title")    public SignUpUserDto signUpUserToSignUpUserDto(SignUpUser signUpUser, String title);    @Mapping(target = "title", source = "title")    public SignUpUser signUpUserDtoToSignUpUser(SignUpUserDto signUpUserDto, Title title);}或者我应该在Mapper中进行转换？@Mapper(componentModel = "spring",  imports = Title.class)public interface SignUpUserMapper {    SignUpUserMapper INSTANCE = Mappers.getMapper(SignUpUserMapper.class);    @Mapping(target = "title", expression = "java(signUpUser.getTitle().toString())")    public SignUpUserDto signUpUserToSignUpUserDto(SignUpUser signUpUser);    @Mapping(target = "title", source = "java(new Title(signUpUserDto.getTitle()))")    public SignUpUser signUpUserDtoToSignUpUser(SignUpUserDto signUpUserDto);}

Answer 1

我应该传递已经在服务中转换的标题吗？

你绝对不应该这样做。这是转换器的工作，而不是服务的

尝试以下方法：

1）枚举类添加转换方法

enum Title {

    ...

    public static Title fromString(String title) {

        if (title != null) {

            for (Title t : Title.values()) {

                if (t.toString().equals(title)) {

                    return t;

                }

            }

        }

        return null;

    }

}

2) Mapper 接口增加2个转换方法（仅限Java 8+）

@Mapper(componentModel = "spring")

public interface SignUpUserMapper {

    SignUpUserDto signUpUserToSignUpUserDto(SignUpUser signUpUser);

    SignUpUser signUpUserDtoToSignUpUser(SignUpUserDto signUpUserDto);

    default String fromEnum(Title title) {

        return title == null ? null : title.toString();

    }

    default Title toEnum(String title) {

        return title == null ? null : Title.fromString(title);

    }

}

Answer 2

像这样使用第二个选项：

 @Mapper(componentModel = "spring",  imports = Title.class)                     

public interface SignUpUserMapper {

SignUpUserMapper INSTANCE = Mappers.getMapper(SignUpUserMapper.class);

@Mapping(target = "title", expression = "java(signUpUser.getTitle().toString())")

public SignUpUserDto signUpUserToSignUpUserDto(SignUpUser signUpUser);

@Mapping(target = "title", source = "java(Title.valueOf(signUpUserDto.getTitle().toUpperCase()))")

public SignUpUser signUpUserDtoToSignUpUser(SignUpUserDto signUpUserDto);            

}