java - How to implement a generic recursive interface? -

another case of java generics confusion...

i defining hierarchy of interfaces must include method return list of interface type. standard use case recursive generic pattern (or whatever name is):

interface superinter<t extends superinter<t>> {     list<t> geteffects(); } 

now when extends interface:

interface subinter extends superinter<subinter> {} 

i can implement sub-interface , have correct method implement:

class subimpl implements subinter {      @override     public list<subinter> geteffects() {         return null;     } } 

and other interface uses generic type have implementing class contain method returns list of interface.

however, can't implement super interface type correctly:

class superimpl implements superinter<superinter> {      @override     public list<superinter> geteffects() {         return null;     } } 

besides raw types warning, get:

bound mismatch: type superinter not valid substitute bounded parameter <t extends superinter<t>> of type superinter<t> 

i guess because class not extends itself. how can achieve this?

you can declare follows:

class superimpl implements superinter<superimpl> {      @override     public list<superimpl> geteffects() {         return null;     } }