How to get the terms matching a WildCardQuery in Lucene 6.2?
I already asked this on StackOverflow. Unfortunately without any answer for over a week now. Therefore again to the real experts: I downloaded a list of 350.000 English words in a .txt file and Indexed it using the latest Lucene (6.2). I want to apply wildcard queries like aard and then retreive a list of matches. I've done this before in an older version of Lucene. Here it was pretty simple. I just had to do a Query.rewrite() and this retuned what I needed. Unfortunately in 6.2 this doesn't work anymore. There is a Query.rewrite(Indexreader reader) which should return a HashMap of Terms. In my case there's only one matching Term (aardvark). The Searcher returns one hit, containing the Document path to the wordlist. The HashMap is however empty. When I change the Query to find more then one single match (like aa*) the HashMap remains empty. I tried the MatchExtractor too. Unfortunately without result. The Objective of this is to demonstrate the power of Lucene to easily find words of a particular length, given one or more characters. I'm pretty sure I can do this using regular expressions in Java but then it's outside my objective. Can anyone tell me why this isn't working? I use the StandardAnalyzer. Should I use a different Application? Any help is greatly appreciated. Thanks. -- Sent from Gmail IPad
RE: How to get the terms matching a WildCardQuery in Lucene 6.2?
Make sure to setRewriteMethod on the MultiTermQuery to: MultiTermQuery.SCORING_BOOLEAN_REWRITE or CONSTANT_SCORE_BOOLEAN_REWRITE Then something like this should work: q = q.rewrite(reader); Set terms = new HashSet<>(); Weight weight = q.createWeight(searcher, false); weight.extractTerms(terms); -Original Message- From: Evert Wagenaar [mailto:evert.wagen...@gmail.com] Sent: Monday, October 24, 2016 12:41 PM To: java-user@lucene.apache.org Subject: How to get the terms matching a WildCardQuery in Lucene 6.2? I already asked this on StackOverflow. Unfortunately without any answer for over a week now. Therefore again to the real experts: I downloaded a list of 350.000 English words in a .txt file and Indexed it using the latest Lucene (6.2). I want to apply wildcard queries like aard and then retreive a list of matches. I've done this before in an older version of Lucene. Here it was pretty simple. I just had to do a Query.rewrite() and this retuned what I needed. Unfortunately in 6.2 this doesn't work anymore. There is a Query.rewrite(Indexreader reader) which should return a HashMap of Terms. In my case there's only one matching Term (aardvark). The Searcher returns one hit, containing the Document path to the wordlist. The HashMap is however empty. When I change the Query to find more then one single match (like aa*) the HashMap remains empty. I tried the MatchExtractor too. Unfortunately without result. The Objective of this is to demonstrate the power of Lucene to easily find words of a particular length, given one or more characters. I'm pretty sure I can do this using regular expressions in Java but then it's outside my objective. Can anyone tell me why this isn't working? I use the StandardAnalyzer. Should I use a different Application? Any help is greatly appreciated. Thanks. -- Sent from Gmail IPad
Re: How to get the terms matching a WildCardQuery in Lucene 6.2?
Thanks Allison. I will try it. Op maandag 24 oktober 2016 heeft Allison, Timothy B. het volgende geschreven: > Make sure to setRewriteMethod on the MultiTermQuery to: > MultiTermQuery.SCORING_BOOLEAN_REWRITE or CONSTANT_SCORE_BOOLEAN_REWRITE > > Then something like this should work: > > q = q.rewrite(reader); > > Set terms = new HashSet<>(); > Weight weight = q.createWeight(searcher, false); > > weight.extractTerms(terms); > > > > -Original Message- > From: Evert Wagenaar [mailto:evert.wagen...@gmail.com ] > Sent: Monday, October 24, 2016 12:41 PM > To: java-user@lucene.apache.org > Subject: How to get the terms matching a WildCardQuery in Lucene 6.2? > > I already asked this on StackOverflow. Unfortunately without any answer > for over a week now. > > Therefore again to the real experts: > > > I downloaded a list of 350.000 English words in a .txt file and Indexed it > using the latest Lucene (6.2). I want to apply wildcard queries like > aard and then retreive a list of matches. > > I've done this before in an older version of Lucene. Here it was pretty > simple. I just had to do a Query.rewrite() and this retuned what I needed. > Unfortunately in 6.2 this doesn't work anymore. There is a > Query.rewrite(Indexreader reader) which should return a HashMap of Terms. > In my case there's only one matching Term (aardvark). The Searcher returns > one hit, containing the Document path to the wordlist. The HashMap is > however empty. > > When I change the Query to find more then one single match (like aa*) the > HashMap remains empty. > > I tried the MatchExtractor too. Unfortunately without result. > > The Objective of this is to demonstrate the power of Lucene to easily find > words of a particular length, given one or more characters. I'm pretty sure > I can do this using regular expressions in Java but then it's outside my > objective. > > Can anyone tell me why this isn't working? I use the StandardAnalyzer. > Should I use a different Application? > > Any help is greatly appreciated. > > Thanks. > > > > -- > Sent from Gmail IPad > -- Sent from Gmail IPad
