使用 mapstruct 映射分层 Bean

Question

这是this问题的扩展。

 class Customer{
  // distinct properties
}
class RetailCustomer extends Customer{
  // distinct properties
}

class WholeSaleCustomer extends Customer{
 // distinct properties
}

class CustomerDO {
 // String custType ; // flag used to determine if Customer is wholeSale or Retail
 //few properties same as Customer/WholeSaleCustomer/RetailCustomer
 // few distinct properties
}

@Mapper
public interface CustomerMapper{

           default Customer toCustomer(CustomerDO customerDO) {
                 String custType = customerDO.getCustType();
                if("W".equalsIgnoreCase(custType)){
                   return toWholeSaleCustomer(customerDO);
                  }
                 else {
                  return toRetailCustomer(CustomerDO);
                   }
           }
        @Mappings({
              @Mapping(source="a", target="b"),
               @Mapping(source="c", target="d"),
               @Mapping(source="m", target="m")
            })
         WholeSaleCustomer toWholeSaleCustomer(CustomerDO customerDO);

       @Mappings({
              @Mapping(source="e", target="f"),
               @Mapping(source="g", target="h"),
               @Mapping(source="n", target="n")
            })
         RetailCustomer toRetailCustomer(CustomerDO customerDO);
}

我需要根据 CustomerDO 中的 custType 标志从 CustomerDO 映射到 WholeSaleCustomer/RetailCustomer。但是上面定义的映射器不起作用。编译时出现以下错误

 CustomerMapper.java:[23,34] Ambiguous mapping methods found for mapping property "com.domain.CustomerDO customerDO" to com.role.Customer: com.role.Customer: toCustomer
r(com.domain.CustomerDO customerDO), com.role.WholeSaleCustomer toWholeSaleCustomer(com.domain.CustomerDO wsCustomer), com.role.RetailCustomer toRetailCustomer(com.domain.CustomerDO wsCustomer)

但是，如果我将 toCustomer(CustomerDo customerDO) 签名更改为 toCustomer(Object customerDO) 并删除 toWholeSaleCustomer/toRetailCustomer 中的任何一个，它就可以工作。它只会映射两种类型中的任何一种。但我两者都想要。我对 Service Bean 有类似的情况。有几个子服务。我应该能够在需要时将它们全部映射

Answer 1

你要找的是Mapping method selection based on qualifiers。

因此，如果您的客户对象如下所示：

class WholeSaleCustomer extends Customer {
 // distinct properties
}

class CustomerDO {
 // String custType ; // flag used to determine if Customer is wholeSale or Retail
 //few properties same as Customer/WholeSaleCustomer/RetailCustomer
 // few distinct properties
    private CustomerDO customerDO;
}

然后你必须告诉 MapStruct 它需要使用哪种方法来执行映射。所以你的映射器看起来像：

@Mapper
public interface CustomerMapper {

        @Named("baseCustomer")
        default Customer toCustomer(CustomerDO customerDO) {
            String custType = customerDO.getCustType();
            if("W".equalsIgnoreCase(custType)){
                return toWholeSaleCustomer(customerDO);
            }
            else {
                return toRetailCustomer(CustomerDO);
            }
        }

        @Mappings({
            @Mapping(source="customerDO", qualifiedByName = "baseCustomer"),
            @Mapping(source="c", target="d"),
            @Mapping(source="m", target="m")
        })
        WholeSaleCustomer toWholeSaleCustomer(CustomerDO customerDO);

        @Mappings({
            @Mapping(source="customerDO", qualifiedByName = "baseCustomer"),
            @Mapping(source="g", target="h"),
            @Mapping(source="n", target="n")
        })
        RetailCustomer toRetailCustomer(CustomerDO customerDO);
}

@Named 应该来自org.mapstruct.Named。