具有泛型和继承的Java抽象类：绑定不匹配

Question

我有2个抽象的类操纵泛型和一个工厂与泛型。父级独立于trips对象和因式分解代码。儿子只基于trips。

//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>
{

Eclipse上的AbstractTripBasedPurchaseExtractor第9行出现错误：Bound mismatch：类型TRIP_PURCHASE不是bounded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>

此处：extends AbstractPurchaseExtractor“

在son类上使用extends，我需要为TRIP_PURCHASE使用扩展abstractServicePurchase的东西。实际上AbstractTripBasedPurchase扩展了AbstractServicePurchase。那为什么会出错呢？

如果我像Eclipse所期望的那样用AbstractServicePurchase替换AbstractTripBasedPurchie，它当然会编译，但我不能在son类上使用我的trip工厂。

Answer 1

最大限度地简化了同样的程序。

它起作用了。

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> { 
}