java - Specify Generics in interface extends -

Should I specify solid type for normal type when extending an interface with an interface?

Do I mean, if I have any interface:

  public interface repo & lt; T & gt; {Collection & lt; T & gt; Search (string parameter); T obtained (string id); }   
 and then a full bunch of specific repositories, such as  ClientRepo ,  Customer Rippo , etc ... to specify this type Appropriate when this interface is extended, for example:  
  Public Interface Client Rippo Repo & lt; Client & gt; {} Public Interface Expands Customer Rippo Repo & lt; Customers & gt; {}   
 Where customers and customers are only a few classes.  
 Does anyone have any such problem? I mean I can:  
  public interface client repo & lt; T & gt;   
  Appendix : I should make my intention more clear to be a special repository (such as a client repo). There is another interface called  RepoFactory  that gives a proper repo to the customer, e.g.:  
  Public Interface RepoFactory {ClientRepo createClientRepo (); Create customer repo customer repo (); }   
 This factory is implemented by  implementers , which, in turn, provide proper implementation of solid repo.  
 In fact, from the top you can say that the interface of the API  repo & lt; T & gt;  is not used.  
 I hope enough confusion !!! Sorry: (  
 
 
 Well it depends if your extended interface / class is normal, I also think that you want to do this  
  the expansion of the public interface Client Rippo repo & lt; Customer & gt; {}   
  
  The public interface expands client repo & lt; T & gt; repo & lt; T & gt; {}   
 you  > 
  Client Rippo> Customer & gt;   
 Is not a desired behavior.