Hello I was trying to use the DuplicateFilter api in contrib/queries for Lucene in an application but it doesn't seem to be accepted as a valid argument to the searcher.search function. I'm using Apache Lucene 2.4.0.
Here's what I did. DuplicateFilter df=new DuplicateFilter("NAME"); df.setKeepMode(DuplicateFilter.KM_USE_FIRST_OCCURRENCE); return indexSearcher.search(query, df); Pretty simple implementation, right? But I keep getting this error: SEVERE: Servlet.service() for servlet jsp threw exception java.lang.VerifyError: (class: search/SearchManager, method: performSearch signature: ([Ljava/lang/String;II)Lorg/apache/lucene/search/TopDocs;) Incompatible argument to function performSearch is my api where I call the above code. If I change the line to return indexSearcher.search(query, (Filter)null); then this error doesn't come up anymore. Could this be a class version issue? ie. the DuplicateFilter class may be in a Jar from a Lucene 2.3 version where the Filter base class was defined with different methods? Does anyone know of a DuplicateFilter class for version 2.4? Has the Filter base class been defined with different methods and that's why this doesn't work? Where can I get the latest version of DuplicateFilter? Thanks for your time and replies DM