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From "Uwe Schindler" <...@thetaphi.de>
Subject RE: Determine whether a MatchAllQuery or a Query with atleast one Term
Date Sat, 28 Nov 2015 11:59:06 GMT
Hi,

You can also traverse a BooleanQuery. Just do instanceof BooleanQuery checks and if it is
a BooleanQuery recursively iterate over all clauses [you can use a BooleanQuery in a for-each
java loop as it implements Iterable]. For each clause recurse and check types again. Then
you should be able to detect all types of queries in the tree.

Uwe

-----
Uwe Schindler
H.-H.-Meier-Allee 63, D-28213 Bremen
http://www.thetaphi.de
eMail: uwe@thetaphi.de

> -----Original Message-----
> From: Sandeep Khanzode [mailto:sandeep_khanzode@yahoo.com.INVALID]
> Sent: Saturday, November 28, 2015 12:22 PM
> To: java-user@lucene.apache.org
> Subject: Re: Determine whether a MatchAllQuery or a Query with atleast
> one Term
> 
> Hi,
> Actually, the MatchAllQuery, for all I know (since it is invoked by the client)
> can be wrapped in a Bool Query type. Hence, it is difficult for me to traverse
> the Bool Query clauses and determine MatchAll, whereas there may be
> other clauses which do contain a TermQuery or a NumericRangeQuery in
> which case a MatchAllQuery check is futile.
> Given any query, Bool Query or MatchAll, or a specific subclass of Query,
> what would be the safe way to determine that this is not a MatchAll query
> without any terms, or whether this is a query that contains at least one term
> or range? -----------------------Thanks n Regards,
> Sandeep Ramesh Khanzode
> 
> 
>     On Saturday, November 28, 2015 12:30 PM, Michael Wilkowski
> <mw@silenteight.com> wrote:
> 
> 
>  Instanceof?
> 
> MW
> Sent from Mi phone
> On 28 Nov 2015 06:57, "Sandeep Khanzode"
> <sandeep_khanzode@yahoo.com.invalid>
> wrote:
> 
> > Hi,
> > I have a question.
> > In my program, I need to check whether the input query is a MatchAll
> Query
> > that contains no terms, or a Query (any variant) that has at least one
> > term. For typical Term queries, this seems reasonable to be done with
> > Query.extractTerms(Set<> terms) which gives the list of terms.
> > However, when there is a NumericRangeQuery, this method throws an
> > UnsupportedOperationException.
> > How can I determine that a NumericRangeQuery or any non-Term query
> exists
> > in the Input Query and differentiate it from the MatchAllQuery? -- SRK
> 
> 
> 


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