Java tutorial
/**************************************************************** * Licensed to the AOS Community (AOS) under one or more * * contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The AOS licenses this file * * to you under the Apache License, Version 2.0 (the * * "License"); you may not use this file except in compliance * * with the License. You may obtain a copy of the License at * * * * http://www.apache.org/licenses/LICENSE-2.0 * * * * Unless required by applicable law or agreed to in writing, * * software distributed under the License is distributed on an * * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * * KIND, either express or implied. See the License for the * * specific language governing permissions and limitations * * under the License. * ****************************************************************/ package aos.lucene.tools; import java.io.IOException; import java.util.Map; import org.apache.lucene.analysis.WhitespaceAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.document.Field; import org.apache.lucene.index.CorruptIndexException; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.Term; import org.apache.lucene.index.IndexWriter.MaxFieldLength; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.TopDocs; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.Sort; import org.apache.lucene.search.SortField; import org.apache.lucene.search.TermQuery; import org.apache.lucene.util.NumericUtils; import org.apache.lucene.spatial.tier.DistanceQueryBuilder; import org.apache.lucene.spatial.tier.DistanceFieldComparatorSource; 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; // From chapter 9 public class SpatialLuceneExample { String latField = "lat"; String lngField = "lon"; String tierPrefix = "_localTier"; private Directory directory; private IndexWriter writer; SpatialLuceneExample() throws IOException { directory = new RAMDirectory(); writer = new IndexWriter(directory, new WhitespaceAnalyzer(Version.LUCENE_46), MaxFieldLength.UNLIMITED); } private void addLocation(IndexWriter writer, String name, double lat, double lng) throws IOException { Document doc = new Document(); doc.add(new Field("name", name, Field.Store.YES, Field.Index.ANALYZED)); doc.add(new Field(latField, NumericUtils.doubleToPrefixCoded(lat), // #A Field.Store.YES, Field.Index.NOT_ANALYZED)); // #A doc.add(new Field(lngField, NumericUtils.doubleToPrefixCoded(lng), // #A Field.Store.YES, Field.Index.NOT_ANALYZED)); // #A doc.add(new Field("metafile", "doc", Field.Store.YES, Field.Index.ANALYZED)); IProjector projector = new SinusoidalProjector(); // #B int startTier = 5; // #C int endTier = 15; // #C for (; startTier <= endTier; startTier++) { CartesianTierPlotter ctp; ctp = new CartesianTierPlotter(startTier, // #D projector, tierPrefix); // #D double boxId = ctp.getTierBoxId(lat, lng); // #D LOGGER.info("Adding field " + ctp.getTierFieldName() + ":" + boxId); doc.add(new Field(ctp.getTierFieldName(), NumericUtils // #E .doubleToPrefixCoded(boxId), Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS)); } writer.addDocument(doc); LOGGER.info("===== Added Doc to index ===="); } /* #A Encode lat/lng as doubles #B Use sinusoidal projection #C Index around 1 to 1000 miles #D Compute bounding box ID #E Add tier field */ public void findNear(String what, double latitude, double longitude, double radius) throws CorruptIndexException, IOException { IndexSearcher searcher = new IndexSearcher(directory); DistanceQueryBuilder dq; dq = new DistanceQueryBuilder(latitude, // #A longitude, // #A radius, // #A latField, // #A lngField, // #A tierPrefix, // #A true); // #A Query tq; if (what == null) tq = new TermQuery(new Term("metafile", "doc")); // #B else tq = new TermQuery(new Term("name", what)); DistanceFieldComparatorSource dsort; // #C dsort = new DistanceFieldComparatorSource( // #C dq.getDistanceFilter()); // #C Sort sort = new Sort(new SortField("foo", dsort)); // #C TopDocs hits = searcher.search(tq, dq.getFilter(), 10, sort); Map<Integer, Double> distances = // #D dq.getDistanceFilter().getDistances(); // #D LOGGER.info("Number of results: " + hits.totalHits); LOGGER.info("Found:"); for (ScoreDoc sd : hits.scoreDocs) { int docID = sd.doc; Document d = searcher.doc(docID); String name = d.get("name"); double rsLat = NumericUtils.prefixCodedToDouble(d.get(latField)); double rsLng = NumericUtils.prefixCodedToDouble(d.get(lngField)); Double geo_distance = distances.get(docID); System.out.printf(name + ": %.2f Miles\n", geo_distance); LOGGER.info("\t\t(" + rsLat + "," + rsLng + ")"); } } /* #A Create distance query #B Match all documents #C Create distance sort #D Get distances map */ public static void main(String[] args) throws IOException { SpatialLuceneExample spatial = new SpatialLuceneExample(); spatial.addData(); spatial.findNear("Restaurant", 38.8725000, -77.3829000, 8); } private void addData() throws IOException { addLocation(writer, "McCormick & Schmick's Seafood Restaurant", 38.9579000, -77.3572000); addLocation(writer, "Jimmy's Old Town Tavern", 38.9690000, -77.3862000); addLocation(writer, "Ned Devine's", 38.9510000, -77.4107000); addLocation(writer, "Old Brogue Irish Pub", 38.9955000, -77.2884000); addLocation(writer, "Alf Laylah Wa Laylah", 38.8956000, -77.4258000); addLocation(writer, "Sully's Restaurant & Supper", 38.9003000, -77.4467000); addLocation(writer, "TGIFriday", 38.8725000, -77.3829000); addLocation(writer, "Potomac Swing Dance Club", 38.9027000, -77.2639000); addLocation(writer, "White Tiger Restaurant", 38.9027000, -77.2638000); addLocation(writer, "Jammin' Java", 38.9039000, -77.2622000); addLocation(writer, "Potomac Swing Dance Club", 38.9027000, -77.2639000); addLocation(writer, "WiseAcres Comedy Club", 38.9248000, -77.2344000); addLocation(writer, "Glen Echo Spanish Ballroom", 38.9691000, -77.1400000); addLocation(writer, "Whitlow's on Wilson", 38.8889000, -77.0926000); addLocation(writer, "Iota Club and Cafe", 38.8890000, -77.0923000); addLocation(writer, "Hilton Washington Embassy Row", 38.9103000, -77.0451000); addLocation(writer, "HorseFeathers, Bar & Grill", 39.01220000000001, -77.3942); writer.close(); } }