在接口扩展中指定泛型 [英] Specify Generics in interface extends

问题描述

我的意思是，如果我有一个接口：

  public interface Repo< T> {
 Collection< T>搜索（String params）; 
 T get（String id）; 
} 
  

然后是一大堆特定的存储库，例如 ClientRepo ， CustomerRepo 等等...扩展此接口时指定类型 T 是合理的，例如：

  public interface ClientRepo extends Repo< Client> {
} 
 public interface CustomerRepo extends Repo< Customer> {
} 
  

客户和客户只是一些类。

有没有人类似的问题？我的意思是我可以这样做：

  public interface ClientRepo< T>扩展Repo< T> {
} 
  

附录：
也许我应该让我的意图是让特定的Repos（例如ClientRepo）更清晰。还有另外一个名为 RepoFactory 的接口，它将适当的回购返回给客户端，例如：

  public interface RepoFactory {
 ClientRepo createClientRepo（）; 
 CustomerRepo createCustomerRepo（）; 
} 
  

该工厂由实施者 ，提供具体Repos的适当实现。

实际上，从上面可以看出， Repo< T> 由api的客户端完成。

足够让我困惑！对不起：（$ / b>

解决方案

原来，我寻找的解决方案只是抛出所有我的专用接口：

$ b $ pre $ public interface RepoFactory {
Repo< Client> createClientRepo（）;
Repo< Customer> createCustomerRepo（）;} $


$ b

通过这种方式，我可以保持我的静态类型检查来执行api并获得更多的灵活性用于我的Factory的实现。

Should I specify the concrete type for generic types when extending an interface with another interface?

What I mean is, if I have an interface:

public interface Repo<T>{
      Collection<T> search(String params);
      T get(String id);
}

and then a whole bunch specific Repositories, like ClientRepo, CustomerRepo, etc... is it reasonable to specify the type T when extending this interface, e.g.:

public interface ClientRepo extends Repo<Client>{
}
public interface CustomerRepo extends Repo<Customer>{
}

where Client and Customer are just some classes.

Did anyone have a similar problem? I mean I could do:

public interface ClientRepo<T> extends Repo<T>{
}

Addendum: Perhaps I should make my intent for having specific Repos (e.g. ClientRepo) more clear. There is another interface called RepoFactory that returns appropriate Repo to the client, e.g.:

public interface RepoFactory{
      ClientRepo createClientRepo();
      CustomerRepo createCustomerRepo();
}

This factory is implemented by implementors which in turn, provide the appropriate implementations of the concrete Repos.

In fact from the above you could say that the interface Repo<T> is not used by the client of the api.

Confusing enough I hope!!! Sorry :(

解决方案

Turns out the solution I was looking for was simply to throw out all my specialized interfaces:

public interface RepoFactory{
    Repo<Client> createClientRepo();
    Repo<Customer> createCustomerRepo(); }

This way I get to both keep my static type-checking to enforce the api and also gain an additional flexibility for implementations of my Factory.

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