Java扩展泛型

Question

这可能吗？

class A<T extends Service<E extends Entity>>

这是因为我想获得服务和实体的类型.或者其他任何方式来做它？

目前我有一个设置服务的抽象方法,但如果我可以在参数中做得更好.

I'm also wondering how can I pass the parameters in a base class:

I have ClassA that extends SubBaseClass1 that extends BaseClass1.

So:

class SubBaseClass1<E extends Entity, P extends Service<E>> { }

In BaseClass, I want to know the type of P and E.

Another question, if I have a method getBaseClass from another class, how will I specify the return type?:

public BaseClass<E extends Entity, T extends Service<E>> getBaseClass() { }

Is not working.

Found the answer:

public BaseClass<? extends IEntity, ? extends Service<?>> getBaseClass() { }

Answer 1

你会这样声明:

class A<E extends Entity, T extends Service<E>>

然后你就可以拥有,例如:

A<Foo, Bar> a;

... where Foo的子类是Entity和Bar的子类Service<Foo>.