I tried using the DuplicateFilter to prevent duplicate search results, but it causes zero search results, even though I know the search should have some results.

This is the code in question:

			

			DuplicateFilter noDupes = new DuplicateFilter("filename");  noDupes.setKeepMode(DuplicateFilter.KM_USE_FIRST_OCCURRENCE);
			

			TopDocs topDocs = searcher.search(query, noDupes,maxHits);
			

		

Any idea what I am doing wrong? If the field "filename" is the same, I want to remove the duplicate.