Spatial lucene simple query doesn't work?
does anyone have any experiences using the lucene's spatial search component (lucene 3.0)?
I tried a very simple example but could not get the search to return anything, see below for all the codes
import java.io.IOException;
import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Index;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.spatial.tier.DistanceQueryBuilder;
import org.apache.lucene.spatial.tier.projections.CartesianTierPlotter;
import org.apache.lucene.spatial.tier.projections.IProjector;
import org.apache.lucene.spatial.tier.projections.SinusoidalProjector;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.NumericUtils;
public class SpatialLuceneExample{
private static final String LAT_FIELD = "lat", LON_FIELD = "lon", TIER_PREFIX_FIELD = "_localTier";
private double maxMiles = 25, minMiles = 1; // anything lower than 1 mile will just give tier 15
// see http://www.nsshutdown.com/projects/lucene/whitepaper/locallucene_v2.html
private IProjector projector = new SinusoidalProjector();
private CartesianTierPlotter ctp = new CartesianTierPlotter(0, projector, TIER_PREFIX_FIELD);
//startTier is 14 for 25 miles, 15 for 1 miles in lucene 3.0
private int startTier = ctp.bestFit(maxMiles), endTier = ctp.bestFit(minMiles);
/**
* Add the lat, lon, and tier box id to the document
* see http://www.nsshutdown.com/projects/lucene/whitepaper/locallucene_v2.html
* @param lat
* @param lon
* @param document a geo document
*/
private void addSpatialLcnFields(double lat, double lon, Document document){
document.add(new Field(LAT_FIELD, NumericUtils.doubleToPrefixCoded(lat), Field.Store.YES, Field.Index.NOT_ANALYZED));
document.add(new Field(LON_FIELD, NumericUtils.doubleToPrefixCoded(lon), Field.Store.YES, Field.Index.NOT_ANALYZED));
for(int tier = startTier ; tier<= endTier; tier++){
CartesianTierPlotter ctp = new CartesianTierPlotter(tier, projector, TIER_PREFIX_FIELD);
double boxId = ctp.getTierBoxId(lat, lon);
document.add(new Field(ctp.ge开发者_Go百科tTierFieldName(), NumericUtils.doubleToPrefixCoded(boxId), Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS));
}
}
private void addLocation(IndexWriter writer, String name, double lat, double lon) throws IOException{
Document doc = new Document();
doc.add(new Field("name", name, Field.Store.YES, Index.ANALYZED));
doc.add(new Field("metafile", "doc", Store.YES, Index.ANALYZED));
addSpatialLcnFields(lat, lon, doc);
writer.addDocument(doc);
}
public static void main(String[] args) throws Exception{
SpatialLuceneExample sle = new SpatialLuceneExample();
Directory dir = new RAMDirectory();
IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), MaxFieldLength.UNLIMITED);
sle.addLocation(writer, "test", 39.9260, -75.1566);
writer.commit();
writer.close();
IndexSearcher searcher = new IndexSearcher(dir);
DistanceQueryBuilder dq = new DistanceQueryBuilder(39.9260, -75.1566, 10d, LAT_FIELD, LON_FIELD, true);
Query tq = new TermQuery(new Term("metafile", "doc"));
TopDocs hits = searcher.search(dq.getQuery(tq), 10);
for(int i =0; i<hits.totalHits; i++){
Document doc = searcher.doc(hits.scoreDocs[i].doc);
System.out.println(doc.get("name"));
}
}
}
Any helps/comments will be greatly appreciated.
You need to add the tier prefix to the query builder:
DistanceQueryBuilder dq = new DistanceQueryBuilder(coord.getLat(),
coord.getLon(), miles, Spatial.LAT_FIELD, Spatial.LON_FIELD,
Spatial.TIER_PREFIX_FIELD, false);
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