具有泛型和继承的java抽象类：绑定不匹配

Question

我有2个抽象类操作泛型，还有1个带有泛型的工厂。 父级独立于旅行对象并分解代码。 儿子仅基于旅行。

//parent
public abstract class AbstractPurchaseExtractor<//
BINDING_CLASS extends ForPnrHandling, //
PURCHASE extends AbstractServicePurchase<?, PRICING, RECEIPT, ITEM, COUPON>, //
PRICING extends PricingDefault, //
RECEIPT extends ReceiptDefault, //
ITEM extends AbstractServiceItem<PURCHASE, COUPON>, //
COUPON extends CouponDefault> //
    implements IPurchaseExtractor<BINDING_CLASS, PURCHASE, PRICING, RECEIPT, ITEM,     COUPON>
...






//son
public abstract class AbstractTripBasedPurchaseExtractor<//
BINDING_CLASS extends ForPnrHandling, //
TRIP_PURCHASE extends AbstractTripBasedPurchase<?, PRICING, RECEIPT, TRIP_BASED_ITEM,         TRIP_BASED_COUPON> , //
PRICING extends PricingDefault, //
RECEIPT extends ReceiptDefault, //
TRIP_BASED_ITEM extends  AbstractTripBasedItem<TRIP_PURCHASE, TRIP_BASED_COUPON, ?>, //
TRIP_BASED_COUPON extends  TripBasedCouponDefault> //
        extends AbstractPurchaseExtractor<BINDING_CLASS, TRIP_PURCHASE, PRICING,     RECEIPT,     TRIP_BASED_ITEM, TRIP_BASED_COUPON> //
{

@Autowired
private AbstractTripBasedPurchaseFactory<TRIP_PURCHASE, PRICING, RECEIPT, TRIP_BASED_ITEM, TRIP_BASED_COUPON> abstractTripBasedPurchaseFactory;
  ...





//factory
public abstract class AbstractTripBasedPurchaseFactory<PURCHASE extends     AbstractTripBasedPurchase<?, PRICING, RECEIPT, ITEM, COUPON>,
                                                   PRICING extends PricingDefault,
                                                   RECEIPT extends ReceiptDefault,
                                                   ITEM extends AbstractTripBasedItem<?     extends AbstractTripBasedPurchase<?, PRICING, RECEIPT, ITEM, COUPON>, COUPON, ?>,
                                                   COUPON extends     TripBasedCouponDefault>
   extends AbstractPurchaseFactory<PURCHASE, PRICING, RECEIPT, ITEM>
{

我在Eclipse上遇到了AbstractTripBasedPurchaseExtractor第9行的错误：绑定不匹配：TRIP_PURCHASE类型不是边界参数的有效替代品

<PURCHASE extends AbstractServicePurchase<?,PRICING, RECEIPT, ITEM,COUPON>> 

类型的

AbstractPurchaseExtractor<BINDING_CLASS,PURCHASE,PRICING, RECEIPT, ITEM,COUPON>

在这里：扩展AbstractPurchaseExtractor'<BINDING_CLASS， TRIP_PURCHASE ...

在子类上使用扩展，我需要为TRIP_PURCHASE使用扩展AbstractServicePurchase的东西。 实际上，AbstractTripBasedPurchase扩展了AbstractServicePurchase。 那么为什么会出错呢？

如果像Eclipse期望的那样，我用AbstractServicePurchase替换AbstractTripBasedPurchase，则当然可以编译，但是我不能在子类上使用我的旅行工厂。

Answer 1

同样最大程度地简化了。

有用。

public interface IGeneric<OBJECT> {
    public void test(OBJECT o);
}


public abstract class Parent<OBJECT extends AbstractProduct> implements IGeneric<OBJECT> {       
}

public abstract class Son<PRODUCT extends Trip> extends Parent<PRODUCT> {
    IService<PRODUCT> service;   
}

public abstract class AbstractProduct {  
}

public class Trip extends AbstractProduct{ 
}

 public interface IService<TRIP extends Trip> { 
}