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：

@Entity
public 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标题成员是String。

• 对于实体title 成员是Title。

映射器应该是什么样子的？

我应该传递已在Service 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，而不是服务的工作

尝试以下方法：

1) 为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) 向 Mapper 接口添加 2 种转换方法（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);
    }
}