I opened https://issues.apache.org/jira/browse/LUCENE-2478 and will fix soon!
----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Uwe Schindler [mailto:u...@thetaphi.de] > Sent: Wednesday, May 26, 2010 9:41 AM > To: java-user@lucene.apache.org > Subject: RE: Filter.getDocIdSet() returning null, and what this means for > CachingWrapperFilter > > Can you open an issue, null should be handled like an empty DocIdSet? This > seems to be a bug in CachingWrapperFilter. > > To go around this, don’t return null, and instead return the constant > DocIdSet.EMPTY_DOCIDSET. This is the preferable solution and maybe we > will change this in Lucene 4.0, to not allow null as return value. > > ----- > Uwe Schindler > H.-H.-Meier-Allee 63, D-28213 Bremen > http://www.thetaphi.de > eMail: u...@thetaphi.de > > > -----Original Message----- > > From: Daniel Noll [mailto:dan...@nuix.com] > > Sent: Wednesday, May 26, 2010 8:57 AM > > To: Lucene Java Users Mailing List > > Subject: Filter.getDocIdSet() returning null, and what this means for > > CachingWrapperFilter > > > > Hi all. > > > > We are seeing an exception like this: > > > > java.lang.NullPointerException > > at > > > org.apache.lucene.search.CachingWrapperFilter.docIdSetToCache(CachingW > > rapperFilter.java:84) > > at > > > org.apache.lucene.search.CachingWrapperFilter.getDocIdSet(CachingWrapp > > erFilter.java:112) > > at > > > com.nuix.storage.search.LazyConstantScoreQuery$LazyFilterWrapper.getDo > > cIdSet(SourceFile:91) > > at > > > org.apache.lucene.search.ConstantScoreQuery$ConstantScorer.<init>(Cons > > t > > antScoreQuery.java:116) > > at > > > org.apache.lucene.search.ConstantScoreQuery$ConstantWeight.scorer(Con > > stantScoreQuery.java:81) > > at > > > org.apache.lucene.search.BooleanQuery$BooleanWeight.scorer(BooleanQu > > ery.java:297) > > at > > > org.apache.lucene.search.BooleanQuery$BooleanWeight.scorer(BooleanQu > > ery.java:297) > > at > > org.apache.lucene.search.QueryWrapperFilter$2.iterator(QueryWrapperFil > > t > > er.java:75) > > > > The class of our own is just an intermediary which delays creating the > > Filter object... > > > > @Override > > public DocIdSet getDocIdSet(IndexReader reader) throws IOException > { > > if (delegate == null) { > > delegate = factory.createFilter(); > > } > > return delegate.getDocIdSet(reader); > > } > > > > Tracing through the code in CachingWrapperFilter, I can see that this > > NPE would occur if getDocIdSet() were to return null. > > > > The Javadoc on Filter says that null will be returned if no documents > > will be accepted by the filter, but it doesn't seem that Lucene itself > > is handling null return values correctly, so which is correct? The code or > > the > Javadoc? > > Supposing that null really is OK, does this cause any problems with > > how CachingWrapperFilter is implementing the caching? I notice it's > > calling get() and then comparing against null so it wouldn't appear > > that it can distinguish "the entry isn't in the cache" from "the entry is > > in the > cache but it's null". > > > > Daniel > > > > > > > > -- > > Daniel Noll Forensic and eDiscovery Software > > Senior Developer The world's most advanced > > Nuix email data analysis > > http://nuix.com/ and eDiscovery software > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
