java修复了在具有相同方法类型的@Qualifier上为映射属性错误找到的不明确映射方法

Question

我使用MapStruct 1.3.1得到了“mapping from map”的不明确映射错误。决赛

@Mapper( uses = MappingUtil.class )
public interface SourceTargetMapper {

    SourceTargetMapper MAPPER = Mappers.getMapper( SourceTargetMapper.class );

    @Mapping(source = "map", target = "aProperty", qualifiedBy = A.class )
    @Mapping(source = "map", target = "bProperty", qualifiedBy = B.class )
    Target toTarget(Map<String,Map<String, Object>> map);
}


public class MappingUtil {

  @Qualifier
  @Target(ElementType.METHOD)
  @Retention(RetentionPolicy.CLASS)
  public @interface A {
  }

  @Qualifier
  @Target(ElementType.METHOD)
  @Retention(RetentionPolicy.CLASS)
  public @interface B {
  }

  @A
  public String abc(Map<String,Map<String, Object>> in) {
     return (String) in.get("first_key").get("a_second_key");
  }

  @B
  public String xyz(Map<String,Map<String, Object>> in) {
     return (String) in.get("first_key").get("b_second_key");
  }

}

当我将@A或@B更改为其他类型时，错误消失了

  @B
  public int xyz(Map<String,Map<String, Object>> in) {
     return (int) in.get("first_key").get("b_second_key");
  }

我错过了什么？{a2}使用了相同类型的两个方法，因此这不应该是一个问题

编辑：Mapstruct 4.1.2上的相同问题。决赛

Answer 1

限定符的实现不正确。下面是link，它展示了如何在映射不明确的情况下使用限定符实现自定义映射

下面是如何基于限定符创建自定义映射的简短代码版本：

@Qualifier
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.CLASS)
public @interface Translator {
}

@Qualifier
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.CLASS)
public @interface A {
}

@Qualifier
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.CLASS)
public @interface B {
}

@Translator
public class MappingUtil {
    @A
    public String abc(Map<String,Map<String, Object>> in) {
        return (String) in.get("first_key").get("a_second_key");
    }

    @B
    public String xyz(Map<String,Map<String, Object>> in) {
        return (String) in.get("first_key").get("b_second_key");
    }
}

@Mapper( uses = MappingUtil.class )
public interface SourceTargetMapper {

    SourceTargetMapper MAPPER = Mappers.getMapper( SourceTargetMapper.class );

    @Mapping(source = "map", target = "aProperty", qualifiedBy = { Translator.class, A.class } )
    @Mapping(source = "map", target = "bProperty", qualifiedBy = { Translator.class, B.class } )
    Target toTarget(Map<String,Map<String, Object>> map);
}

备选方案：

如果不想创建单独的实用程序类，可以使用qualifiedByName。下面是它的示例代码：

@Mapper
public interface SourceTargetMapper {

    SourceTargetMapper MAPPER = Mappers.getMapper( SourceTargetMapper.class );

    @Mapping(source = "map", target = "aProperty", qualifiedByName= "abc" )
    @Mapping(source = "map", target = "bProperty", qualifiedByName= "xyz" )
    Target toTarget(Map<String,Map<String, Object>> map);

    @Named("abc")
    default String abc(Map<String,Map<String, Object>> in) {
        // return whatever need to return
    }

    @Named("xyz")
    default String xyz(Map<String,Map<String, Object>> in) {
        // return whatever need to return
    }
}

Answer 2

在使用1.4.2时，这似乎是正确的。最终的但是，在1.5.0中。Beta1由于新引入了映射到Bean的映射，这不再有效。我们正在调查如何解决这个问题

但是，有一种替代解决方案可以使其正常工作：

@Mapper( uses = MappingUtil.class )
public interface SourceTargetMapper {

    SourceTargetMapper MAPPER = Mappers.getMapper( SourceTargetMapper.class );

    @Mapping(source = "first_property", target = "aProperty", qualifiedBy = A.class )
    @Mapping(source = "first_property", target = "bProperty", qualifiedBy = B.class )
    Target toTarget(Map<String,Map<String, Object>> map);
}


public class MappingUtil {

  @Qualifier
  @Target(ElementType.METHOD)
  @Retention(RetentionPolicy.CLASS)
  public @interface A {
  }

  @Qualifier
  @Target(ElementType.METHOD)
  @Retention(RetentionPolicy.CLASS)
  public @interface B {
  }

  @A
  public String abc(Map<String, Object> in) {
     return (String) in.get("a_second_key");
  }

  @B
  public String xyz(Map<String, Object> in) {
     return (String) in.get("b_second_key");
  }

}

注意MappingUtil中签名的更改和Mapping#source中的更改