ArcGISExtension cannot be resolved to a type

Discussion created by tincho07 on Sep 22, 2010
I want to develop a geoprocessing tool in Eclipse, but I have some problems in CustomFunctionFactory.java class:
-ArcGISCategories cannot be resolved
-ArcGISExtension cannot be resolved to a type
-The attribute categories is undefined for the annotation type ArcGISExtension

I think some library is missing, but i cant solve it.

I really would apreciate your help!