2

当映射信息由第二个映射函数明确提供给 Mapstruct 时，为什么这不会自动生成映射代码？

Flat          Composed
----          --------
- String a    - String a
              - Sub
- String b      - String b
- String c      - String c

.

@Mapper(uses = SubToFlatMapper.class)
public interface ComposedToFlatMapper {

    Flat map(Composed c); // Unmapped target properties: "b, c".
                          // Not OK because Sub mapping is defined in 
                          //    SubToFlatMapper and is used here :(
}

@Mapper
public interface SubToFlatMapper {

    Flat map(Sub s); // Unmapped target properties: "a".
                     //    (OK because 'a' is not in Sub)
}

为清楚起见的用法：

Composed composed = new Composed();
Sub sub = new Sub();

composed.setA("A");
composed.setSub(sub);

sub.setB("B");
sub.setC("C");

Flat flat = ComposedToFlatMapper.INSTANCE.map(composed);

// flat.getA() is "A", OK!
// flat.getB() is null, unexpected, should be "B"
// flat.getC() also null, should be "C".

"B"并且"C"没有映射到，flat因为生成代码没有为此创建方法。

我以为我已经向生成器提供了所需的映射信息。ComposedToFlatMapperImpl当它看到该Flat map(Sub s)方法时，它应该在内部生成。

编辑：

我之前没有提到这一点，但在最初的问题中，我也可以使用update更灵活的 -methods。

现在，假设有一个新Sub2类型。：

@Mapper(uses = {SubToFlatMapper.class, Sub2ToFlatMapper.class})
public interface ComposedToFlatMapper {

    Flat map(Composed c);

    void update(Composed source, @MappingTarget Flat target);
}

@Mapper
public interface SubToFlatMapper {

    Flat map(Sub s); 

    void update(Sub source, @MappingTarget Flat target);
}

@Mapper
public interface Sub2ToFlatMapper {

    Flat map(Sub2 s); 

    void update(Sub2 source, @MappingTarget Flat target);
}

.

Flat          Composed
----          --------
- String a    - String a
              - Sub
- String b      - String b
- String c      - String c
              - Sub2
                - String d
                - String e

由于Flat没有Sub2参考，请忽略它。无需生成映射代码。

4

1 回答 1

1

您可以像这样简单地展平嵌套的源结构：

@Mapper
public interface ComposedToFlatMapper {

    @Mapping(target="b", source="sub.b")
    @Mapping(target="c", source="sub.c")
    Flat map(Composed c);
}
于 2017-01-15T17:33:01.280 回答