getMethods Reflection API result is ambiguous with Interface

Please have a look on the scenario and suggest how can I remove the following issue.

1. We have an interface BaseRepository which is already build in having a method commitData(), retrieveData(), sortByLength().

    public interface BaseRepository{
          public void commitData();
          public Object retrieveData();
          public Object sortByLength();
       }
   

2. Interface FileRepository which extends BaseRepository having methods commitData(), fileNames() i.e.

   public interface FileRepository extends BaseRepository{
               public void commitData();
               public List fileNames();
           }
   

3. Interface ObjectRepository which extends both BaseRepository and FileRepository with no methods in it.

4. Using Java Reflection API I try to get the methods define in the Interfaces for further processing, but getting method commitData 2 times i.e. following piece of code will give me 2 time commitData in the console

   for(Method method : ObjectRepository.class.getMethods()){
               System.out.println(method.getName());
           }
   

output is:

commitData retrieveData sortByLength commitData fileNames

I am using Java 1.6.