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From Jawahar Lal <j...@chambal.com>
Subject Re: Getting
Date Fri, 24 Dec 2010 11:43:53 GMT
I open a IndexReader. I want to see how many docs are indexed, to get this
count I used

objReader.maxDoc()  ... its returning me 0.

How can I get the total no. of docs in index?

On 24 December 2010 16:36, Jawahar Lal <jlal@chambal.com> wrote:

> Thanks Umesh
>
>  I want to know more about Filters, how to use that using lucene 3.0.3
>
> Can I get links to learn how/when to use filters.
>
> jawahar
>
>
> On 24 December 2010 16:25, Umesh Prasad <umesh.iitk@gmail.com> wrote:
>
>> Yes.
>>
>> Also note that , topdocs.totalhits will always give u total number of
>> hits,
>> regardless of the number of score doc u choose to retrieve.
>>  topdocs.scoredocs will have min(totalhits, ndocs) docs populated.
>>
>>
>> On Fri, Dec 24, 2010 at 2:48 PM, Jawahar Lal <jlal@chambal.com> wrote:
>>
>> > ok, I understand.
>> >
>> > It means, that we have to fetch total no. of docs i.e.
>> >
>> > Suppose we need to show 100 docs per page
>> >
>> > Page No.     NDocs       No. of documents to be shown on Page
>> > 1                  100            0-99
>> > 2                   200           100-199
>> > 3                   300            200-299  & so on...
>> >
>> >
>> >
>> >
>> >
>> > On 24 December 2010 12:35, Umesh Prasad <umesh.iitk@gmail.com> wrote:
>> >
>> > > Hi Jawahar,
>> > >   http://search-lucene.com/m/duTpc14AmzV
>> > > See Uwe's reply.
>> > >
>> > >
>> > >
>> > > Regards
>> > > Umesh
>> > >
>> > > PS: I would use search-lucene.com to 1st check if a solution is
>> posted
>> > > already. It is really good.
>> > >
>> > > ------------------------
>> > > QUOTED UWE's reply
>> > > ----------------------
>> > >
>> > > To get the second page,
>> > > Take:
>> > > int hitsPerPage = 10;
>> > > int pageOffset = 10;
>> > > TopDocCollector collector = new TopDocCollector(hitsPerPage +
>> > pageOffset);
>> > >
>> > > For page third page take int pageOffset = 20; and so on
>> > >
>> > > After that your results are in hits[], for the first page in [0] to
>> [9],
>> > > the
>> > > second page in [10] to [19] and so on:
>> > >
>> > > To display use something like:
>> > > For (int i=pageOffset; Math.min(hitsPerPage + pageOffset,
>> > > collector.topDocs().totalhits); i++)
>> > >
>> > > In general, you cannot retrieve a range directly, you can only
>> retrieve
>> > the
>> > > top docs. As most people will not go beyond say page 10 when
>> searching,
>> > you
>> > > have no memory problem, as scoreDocs will contain at most 100 doc ids.
>> > >
>> > > ---------------
>> > > -------------------
>> > >
>> > >
>> > > On Fri, Dec 24, 2010 at 10:40 AM, Jawahar Lal <jlal@chambal.com>
>> wrote:
>> > >
>> > > > Hi,
>> > > >
>> > > >  I search for an query. Total searched records are 5000. I only
>> shows
>> > 100
>> > > > records on one page. So I passed 100 as nDocs.
>> > > >
>> > > > I write the code in this way.
>> > > >
>> > > >           IndexSearcher searcher = new
>> > IndexSearcher(FSDirectory.open(new
>> > > > File(path)));
>> > > >
>> > > >            Query query = new QueryParser(Version.LUCENE_30,
>> "field1",
>> > new
>> > > > StandardAnalyzer(Version.LUCENE_30)).parse("query");
>> > > >            Query query1 = new QueryParser(Version.LUCENE_30,
>> "field2",
>> > > new
>> > > > StandardAnalyzer(Version.LUCENE_30)).parse("query2");
>> > > >            BooleanQuery lucBoolQueryOTHER = new BooleanQuery();
>> > > >            lucBoolQueryOTHER.add(query, Occur.MUST);
>> > > >            lucBoolQueryOTHER.add(query1, Occur.MUST);
>> > > >
>> > > >            TopDocs hits=searcher.search(query, null, 100);
>> > > >
>> > > >            System.err.println("Total searched " + hits.totalHits);
>> >>
>> > > > 5000
>> > > >            System.err.println("Total docs " +
>> hits.scoreDocs.length);
>> >  >>
>> > > > 100
>> > > >
>> > > > // The code to print 100 records on first page
>> > > >            for(int i=0;i<hits.scoreDocs.length;i++){
>> > > >
>> > > >
>> > > >
>> > >
>> >
>> System.out.println(searcher.doc(hits.scoreDocs[i].doc).getField("filename"));
>> > > >            }
>> > > >
>> > > > it worked fine.
>> > > >
>> > > > // Now I want to show all next search documents on Second
>> Pages...when
>> > I
>> > > > tried in this way, I got the error.
>> > > >            for(int i=100;i<hits.totalHits;i++){
>> > > >
>> > > >
>> > > >
>> > >
>> >
>> System.out.println(searcher.doc(hits.scoreDocs[i].doc).getField("filename"));
>> > > >            }
>> > > >
>> > > >            searcher.close();
>> > > >
>> > > > java.lang.ArrayIndexOutOfBoundsException: 100
>> > > >        at Test.searchIndex(Test.java:96)
>> > > >        at Test.main(Test.java:54)
>> > > >
>> > > > Would need to perform searching again with different parameters to
>> > fetch
>> > > > next bunch of records ?
>> > > >
>> > > >
>> > > >
>> > > >
>> > > > Thanks
>> > > >
>> > >
>> > >
>> > >
>> > > --
>> > > ---
>> > > Thanks & Regards
>> > > Umesh Prasad
>> > >
>> >
>>
>>
>>
>> --
>> ---
>> Thanks & Regards
>> Umesh Prasad
>>
>
>

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