问题描述
我正在使用 MapStruct 进行dto <-> entity映射.相同的映射器用于从dtos 创建 和 更新实体.完成对dto ID的验证，以了解是否必须创建一个新实体(id == null)还是应该从数据库中检索它(id！= null).
I'm using MapStruct to make dto <-> entity mapping. The same mappers are used to create and update entities from dtos. A verification of the dto's id is done to know whether a new entity must be created (id == null) or it should be retrieved from database (id != null) .
我实际上在使用 MapperDecorator 作为解决方法.示例:
I'm actually using MapperDecorator as a workaround. Example :
@Mapper
@DecoratedWith(UserAccountDecorator.class)
public interface UserAccountMapper {
UserAccountDto map(User user);
User map(UserAccountDto dto);
User map(UserAccountDto dto, @MappingTarget User user);
}
装饰器
public abstract class UserAccountDecorator implements UserAccountMapper {
@Autowired
@Qualifier("delegate")
private UserAccountMapper delegate;
@Autowired
private UserRepository userRepository;
@Override
public User map(UserAccountDto dto) {
if (dto == null) {
return null;
}
User user = new User();
if (dto.getId() != null) {
user = userRepository.findOne(dto.getId());
}
return delegate.map(dto, user);
}
}
但是，由于必须为每个映射器创建一个装饰器，因此该解决方案变得繁重.
But this solution becomes heavy due to the fact that a decorator must be created for each mapper.
有什么好的解决方案吗?
Is there any good solution to perform that ?
我正在使用:
- MapStruct: 1.1.0
推荐答案
我通过遵循 Gunnar 的建议解决了我的问题>在.
I solved my problem by following the advice of Gunnar in the comment.
我转到了 MapStruct 1.2.0 .Beta1 并创建了一个如下所示的UserMapperResolver
I moved to MapStruct 1.2.0.Beta1 and created a UserMapperResolver like below
@Component
public class UserMapperResolver {
@Autowired
private UserRepository userRepository;
@ObjectFactory
public User resolve(BaseUserDto dto, @TargetType Class<User> type) {
return dto != null && dto.getId() != null ? userRepository.findOne(dto.getId()) : new User();
}
}
然后在UserMapper中使用哪个:
Which I use then in my UserMapper :
@Mapper(uses = { UserMapperResolver.class })
public interface BaseUserMapper {
BaseUserDto map(User user);
User map(BaseUserDto baseUser);
}
现在生成的代码是:
@Override
public User map(BaseUserDto baseUser) {
if ( baseUser == null ) {
return null;
}
User user = userMapperResolver.resolve( baseUser, User.class );
user.setId( baseUser.getId() );
user.setSocialMediaProvider( baseUser.getSocialMediaProvider() );
...
}
效果很好！
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