MapStruct：来自不同实体的字段映射到同一实体的不同字段

Question

我有 Class A、B 和 C。Class A 有三个变量，它根据 Class B 和 C 的不同字段填充。当我使用 mapper 来填充对象仅保留最后使用的映射器值。我怎样才能确保所有值都被填充。我正在使用 MapStruct 映射器（版本 1.2.0）和 Spring 引导版本 2.0.3

Sample code below:
Class A{

  String a;
  String b;
  String c;

  }

Class B{
 String b1;
}

Class C{
    String c1;
}

public interface AtoCmapper{
  @Mappings({
      @Mapping(target="c", source="source.c1")
  })
  A CtoA(C source);

  @Mappings({
      @Mapping(target="c1", source="source.c")
  })
  C AtoC(A source);
}

public interface AtoBmapper{
  @Mappings({
      @Mapping(target="b", source="source.b1")
  })
  A BtoA(B source);

  @Mappings({
      @Mapping(target="b1", source="source.b")
  })
  B AtoB(A source);
}

Class DAO{

 @Autowired
 AtoBmapper aToBMapper;

 @Autowired
 AtoCmapper aToCMapper;

 public void testMapping(){
  A aObject = new A();

  aObject = aToBMapper(bObject); // Assume bObject is object to Type B and it is initialized properly

  aObject = aToCMapper(cObject); // Assume cObject is object to Type B and it is initialized properly
 }

 //Now when I call testMapping() resulting A object only has value set for variable c, value of b is lost.
 How can I make sure that Values from B and C are set properly to Class A
}

Answer 1

MapStruct 可以update existing instances！为此，通过具有第二个 @MappingTarget 类型 A 注释参数的变体引入新的映射方法（或替换旧方法）（在这种情况下，可以替换 return输入 void):

// In AtoBmapper
@Mappings(...)
void updateAFromB(B source, @MappingTarget A target);

// In AtoCmapper
@Mappings(...)
void updateAFromC(C source, @MappingTarget A target);

那你可以这样写：

A aObject = new A();

aToBMapper.updateAFromB(bObject, aObject);
aToCMapper.updateAFromC(cObject, aObject);

// now aObject should contain the cumulated data from b and c

MapStruct：来自不同实体的字段映射到同一实体的不同字段

MapStruct: Fields from Different Entities mapping to Same Entity Different fields

java

spring

spring-boot

mapstruct