How to implemnt dupplicate key map...

[dumani jayasinghe]

Please can any one guide me to implement map with duplicate key?

[Joseph Mokenela]

I would suggest you check the following link.

http://stackoverflow.com/questions/1062960/map-implementation-with-duplicate-keys

Hope that helps!

[Campbell Ritchie]

That is a contradiction in terms. A map represents a function, and a function cannot have duplicate results from one input.
It is easy to have duplicate values.

Map<Name, Forum> moderators = new HashMap<Name, Forum>();
 . . .
Forum beginning = new Forum("Beginning Java");
moderators.put(new Name("Campbell Ritchie"), beginning);
moderators.put(new Name("Janeice del Vecchio"), beginning)

. . . will work, but this wont't:

Map<Name, Forum> moderators = new HashMap<Name, Forum>();
 . . .
Forum beginning = new Forum("Beginning Java");
Forum bunkhouse = new Forum("Bunkhouse Porch");
Name campbell = new Name("Campbell Ritchie);
moderators.put(campbell, beginning);
moderators.put(campbell, bunkhouse)

you will ony ever get Bunkhouse Porch out of that Map.