java - 具有复合或抽象工厂的工厂

Question

我有以下类层次结构:

public interface RateSheetProductExtractor
{
  List<ProductData> extract(SGQuotingData quotingData);
}


@Service
@Scope("requestjob")
public class ProductExtractorFactory
{
  @Autowired
  private OptionalRatingProductExtractorFactory optionalRatingProductExtractorFactory;
  @Autowired
  private QuotePlanProductExtractorFactory quotePlanProductExtractorFactory;
  @Autowired
  private AlternateProductExtractorFactory alternateProductExtractorFactory;

  public RateSheetProductExtractor getProductExtractor(
    TablePlanType tablePlanType,
    TableRatingType ratingType)
  {
    switch (tablePlanType)
    {
      case QUOTED:
        return quotePlanProductExtractorFactory.getInstance(ratingType);
      case OPTIONAL:
        return optionalRatingProductExtractorFactory.getInstance(ratingType);
      case ALTERNATE:
        return alternateProductExtractorFactory.getInstance(ratingType);
      default:
        throw new IllegalArgumentException(tablePlanType + " is unsupported yet.");
    }
  }
}

@Service
@Scope("requestjob")
public class OptionalRatingProductExtractorFactory
{
  @Autowired
  private AcaProductExtractor acaProductExtractor;
  @Autowired
  private AgeRatedAsCompositeProductExtractor ageRatedAsCompositeProductExtractor;

  public RateSheetProductExtractor getInstance(TableRatingType ratingType)
  {
    switch (ratingType)
    {
      case AGE:
        return ageRatedAsCompositeProductExtractor;
      case COMPOSITE:
        return acaProductExtractor;
      default:
        throw new IllegalArgumentException(
          "Product extractor isn't defined for optional plan type and rating type " + ratingType);

    }
  }
}


@Service
@Scope("requestjob")
public class QuotePlanProductExtractorFactory
{
  @Autowired
  private GfProductExtractor gfExtractor;
  @Autowired
  private AgeRatedProductExtractor ageRatedProductExtractor;
  @Autowired
  private MedicalProductExtractor medicalProductExtractor;

  public RateSheetProductExtractor getInstance(TableRatingType ratingType)
  {
    switch (ratingType)
    {
      case AGE:
        return ageRatedProductExtractor;
      case COMPOSITE_AGE:
        return gfExtractor;
      case COMPOSITE:
        return medicalProductExtractor;
      default:
        throw new IllegalArgumentException(
          ratingType + " is unsupported for QuotePlan product extractor factory.");
    }
  }
}


@Service
@Scope("requestjob")
public class AlternateProductExtractorFactory
{
  @Autowired
  private AlternateAgeRatedProductExtractor ageRatedProductExtractor;

  public RateSheetProductExtractor getInstance(TableRatingType ratingType)
  {
    if (ratingType == AGE)
    {
      return ageRatedProductExtractor;
    }
    throw new IllegalArgumentException(
      ratingType + " is unsupported for QuotePlan product extractor factory.");
  }
}

将 ProductExtractorFactory 称为 AbstractProductExtractorFactory(基于适当的模式)是否正确？或者它更像是一个简单的工厂中的工厂？

抱歉，列表太大...:)

Answer 1

我不这么认为。

1) ProductExtractorFactory 是一个具体类，在 Java 中，甚至在 AbstractFactory 模式中，以 Abstract 开头的类是/应该是一个抽象类。

2)在抽象工厂中，每个工厂应该有一个具体的 RateSheetProductExtractor 子类型，但在您的代码示例中我没有看到它们。

3)您的示例更像是工厂和复合模式。

重构以使用复合:

定义通用工厂接口(interface):

public interface RateSheetProductExtractorFactory{

    public RateSheetProductExtractor getProductExtractor(TablePlanType tablePlanType, TableRatingType ratingType);
}

定义复合类:

public class CompositeRateSheetProductExtractorFactory implements RateSheetProductExtractorFactory{
    private Map<String, RateSheetProductExtractorFactory> factoryMap = null;

    public void setFactoryMap(Map<String, RateSheetProductExtractorFactory> factoryMap){
        this.factoryMap = factoryMap;
    }

    @Override
    public RateSheetProductExtractor getProductExtractor(TablePlanType tablePlanType, TableRatingType ratingType){
        RateSheetProductExtractorFactory factory = factoryMap.get( tablePlanType + "-" + ratingType );

        if (factory == null) throw new IllegalArgumentException( tablePlanType + "-" + ratingType + " is unsupported yet.");

        return factory.getProductExtractor(tablePlanType, ratingType);
    }        
}

实现每个提取器及其各自的工厂:

public class AcaProductExtractorFactory implements RateSheetProductExtractorFactory{

    @Override
    public RateSheetProductExtractor getProductExtractor(TablePlanType tablePlanType, TableRatingType ratingType){
        return new AcaProductExtractor();
    }
}

public class AcaProductExtractor implements RateSheetProductExtractor{

    @Override
    public List<ProductData> extract(SGQuotingData quotingData) {
        return null;
    }        
}



public class AgeRatedAsCompositeProductExtractorFactory implements RateSheetProductExtractorFactory{

    @Override
    public RateSheetProductExtractor getProductExtractor(TablePlanType tablePlanType, TableRatingType ratingType){
        return new AgeRatedAsCompositeProductExtractor();
    }
}

public class AgeRatedAsCompositeProductExtractor implements RateSheetProductExtractor{

    @Override
    public List<ProductData> extract(SGQuotingData quotingData) {
        return null;
    }        
}



public class MedicalProductExtractorFactory implements RateSheetProductExtractorFactory{

    @Override
    public RateSheetProductExtractor getProductExtractor(TablePlanType tablePlanType, TableRatingType ratingType){
        return new MedicalProductExtractor();
    }
}

public class MedicalProductExtractor implements RateSheetProductExtractor{
    @Override
    public List<ProductData> extract(SGQuotingData quotingData) {
        return null;
    }       
}

Spring XML:

<bean id="ageRatedAsCompositeProductExtractorFactory" class="AgeRatedAsCompositeProductExtractorFactory"/>
<bean id="medicalProductExtractorFactory" class="MedicalProductExtractorFactory"/>
<bean id="acaProductExtractorFactory" class="AcaProductExtractorFactory"/>

<bean id="extractorFactory" class="CompositeRateSheetProductExtractorFactory">
    <property name="factoryMap">
        <map>
            <entry key="QUOTED-AGE" value-ref="ageRatedAsCompositeProductExtractorFactory" />
            <entry key="QUOTED-COMPOSITE" value-ref="medicalProductExtractorFactory" />
            <entry key="ALTERNATE-AGE" value-ref="ageRatedAsCompositeProductExtractorFactory" />
            <entry key="OPTIONAL-COMPOSITE" value-ref="acaProductExtractorFactory" />
        </map>
    </property>
</bean>