Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF 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 org.apache.lucene.document; import org.apache.lucene.geo.Polygon; import org.apache.lucene.index.FieldInfo; import org.apache.lucene.index.PointValues; import org.apache.lucene.search.BooleanClause; import org.apache.lucene.search.BooleanQuery; import org.apache.lucene.search.BooleanClause.Occur; import org.apache.lucene.search.BoostQuery; import org.apache.lucene.search.ConstantScoreQuery; import org.apache.lucene.search.MatchNoDocsQuery; import org.apache.lucene.search.PointRangeQuery; import org.apache.lucene.search.Query; import org.apache.lucene.util.BytesRef; import org.apache.lucene.util.NumericUtils; import static org.apache.lucene.geo.GeoEncodingUtils.decodeLatitude; import static org.apache.lucene.geo.GeoEncodingUtils.decodeLongitude; import static org.apache.lucene.geo.GeoEncodingUtils.encodeLatitude; import static org.apache.lucene.geo.GeoEncodingUtils.encodeLatitudeCeil; import static org.apache.lucene.geo.GeoEncodingUtils.encodeLongitude; import static org.apache.lucene.geo.GeoEncodingUtils.encodeLongitudeCeil; /** * An indexed location field. * <p> * Finding all documents within a range at search time is * efficient. Multiple values for the same field in one document * is allowed. * <p> * This field defines static factory methods for common operations: * <ul> * <li>{@link #newBoxQuery newBoxQuery()} for matching points within a bounding box. * <li>{@link #newDistanceQuery newDistanceQuery()} for matching points within a specified distance. * <li>{@link #newPolygonQuery newPolygonQuery()} for matching points within an arbitrary polygon. * </ul> * <p> * If you also need per-document operations such as sort by distance, add a separate {@link LatLonDocValuesField} instance. * If you also need to store the value, you should add a separate {@link StoredField} instance. * <p> * <b>WARNING</b>: Values are indexed with some loss of precision from the * original {@code double} values (4.190951585769653E-8 for the latitude component * and 8.381903171539307E-8 for longitude). * @see PointValues * @see LatLonDocValuesField */ // TODO ^^^ that is very sandy and hurts the API, usage, and tests tremendously, because what the user passes // to the field is not actually what gets indexed. Float would be 1E-5 error vs 1E-7, but it might be // a better tradeoff? then it would be completely transparent to the user and lucene would be "lossless". public class LatLonPoint extends Field { /** LatLonPoint is encoded as integer values so number of bytes is 4 */ public static final int BYTES = Integer.BYTES; /** * Type for an indexed LatLonPoint * <p> * Each point stores two dimensions with 4 bytes per dimension. */ public static final FieldType TYPE = new FieldType(); static { TYPE.setDimensions(2, Integer.BYTES); TYPE.freeze(); } /** * Change the values of this field * @param latitude latitude value: must be within standard +/-90 coordinate bounds. * @param longitude longitude value: must be within standard +/-180 coordinate bounds. * @throws IllegalArgumentException if latitude or longitude are out of bounds */ public void setLocationValue(double latitude, double longitude) { final byte[] bytes; if (fieldsData == null) { bytes = new byte[8]; fieldsData = new BytesRef(bytes); } else { bytes = ((BytesRef) fieldsData).bytes; } int latitudeEncoded = encodeLatitude(latitude); int longitudeEncoded = encodeLongitude(longitude); NumericUtils.intToSortableBytes(latitudeEncoded, bytes, 0); NumericUtils.intToSortableBytes(longitudeEncoded, bytes, Integer.BYTES); } /** * Creates a new LatLonPoint with the specified latitude and longitude * @param name field name * @param latitude latitude value: must be within standard +/-90 coordinate bounds. * @param longitude longitude value: must be within standard +/-180 coordinate bounds. * @throws IllegalArgumentException if the field name is null or latitude or longitude are out of bounds */ public LatLonPoint(String name, double latitude, double longitude) { super(name, TYPE); setLocationValue(latitude, longitude); } @Override public String toString() { StringBuilder result = new StringBuilder(); result.append(getClass().getSimpleName()); result.append(" <"); result.append(name); result.append(':'); byte bytes[] = ((BytesRef) fieldsData).bytes; result.append(decodeLatitude(bytes, 0)); result.append(','); result.append(decodeLongitude(bytes, Integer.BYTES)); result.append('>'); return result.toString(); } /** sugar encodes a single point as a byte array */ private static byte[] encode(double latitude, double longitude) { byte[] bytes = new byte[2 * Integer.BYTES]; NumericUtils.intToSortableBytes(encodeLatitude(latitude), bytes, 0); NumericUtils.intToSortableBytes(encodeLongitude(longitude), bytes, Integer.BYTES); return bytes; } /** sugar encodes a single point as a byte array, rounding values up */ private static byte[] encodeCeil(double latitude, double longitude) { byte[] bytes = new byte[2 * Integer.BYTES]; NumericUtils.intToSortableBytes(encodeLatitudeCeil(latitude), bytes, 0); NumericUtils.intToSortableBytes(encodeLongitudeCeil(longitude), bytes, Integer.BYTES); return bytes; } /** helper: checks a fieldinfo and throws exception if its definitely not a LatLonPoint */ static void checkCompatible(FieldInfo fieldInfo) { // point/dv properties could be "unset", if you e.g. used only StoredField with this same name in the segment. if (fieldInfo.getPointDataDimensionCount() != 0 && fieldInfo.getPointDataDimensionCount() != TYPE.pointDataDimensionCount()) { throw new IllegalArgumentException("field=\"" + fieldInfo.name + "\" was indexed with numDims=" + fieldInfo.getPointDataDimensionCount() + " but this point type has numDims=" + TYPE.pointDataDimensionCount() + ", is the field really a LatLonPoint?"); } if (fieldInfo.getPointNumBytes() != 0 && fieldInfo.getPointNumBytes() != TYPE.pointNumBytes()) { throw new IllegalArgumentException("field=\"" + fieldInfo.name + "\" was indexed with bytesPerDim=" + fieldInfo.getPointNumBytes() + " but this point type has bytesPerDim=" + TYPE.pointNumBytes() + ", is the field really a LatLonPoint?"); } } // static methods for generating queries /** * Create a query for matching a bounding box. * <p> * The box may cross over the dateline. * @param field field name. must not be null. * @param minLatitude latitude lower bound: must be within standard +/-90 coordinate bounds. * @param maxLatitude latitude upper bound: must be within standard +/-90 coordinate bounds. * @param minLongitude longitude lower bound: must be within standard +/-180 coordinate bounds. * @param maxLongitude longitude upper bound: must be within standard +/-180 coordinate bounds. * @return query matching points within this box * @throws IllegalArgumentException if {@code field} is null, or the box has invalid coordinates. */ public static Query newBoxQuery(String field, double minLatitude, double maxLatitude, double minLongitude, double maxLongitude) { // exact double values of lat=90.0D and lon=180.0D must be treated special as they are not represented in the encoding // and should not drag in extra bogus junk! TODO: should encodeCeil just throw ArithmeticException to be less trappy here? if (minLatitude == 90.0) { // range cannot match as 90.0 can never exist return new MatchNoDocsQuery("LatLonPoint.newBoxQuery with minLatitude=90.0"); } if (minLongitude == 180.0) { if (maxLongitude == 180.0) { // range cannot match as 180.0 can never exist return new MatchNoDocsQuery("LatLonPoint.newBoxQuery with minLongitude=maxLongitude=180.0"); } else if (maxLongitude < minLongitude) { // encodeCeil() with dateline wrapping! minLongitude = -180.0; } } byte[] lower = encodeCeil(minLatitude, minLongitude); byte[] upper = encode(maxLatitude, maxLongitude); // Crosses date line: we just rewrite into OR of two bboxes, with longitude as an open range: if (maxLongitude < minLongitude) { // Disable coord here because a multi-valued doc could match both rects and get unfairly boosted: BooleanQuery.Builder q = new BooleanQuery.Builder(); // E.g.: maxLon = -179, minLon = 179 byte[] leftOpen = lower.clone(); // leave longitude open NumericUtils.intToSortableBytes(Integer.MIN_VALUE, leftOpen, Integer.BYTES); Query left = newBoxInternal(field, leftOpen, upper); q.add(new BooleanClause(left, BooleanClause.Occur.SHOULD)); byte[] rightOpen = upper.clone(); // leave longitude open NumericUtils.intToSortableBytes(Integer.MAX_VALUE, rightOpen, Integer.BYTES); Query right = newBoxInternal(field, lower, rightOpen); q.add(new BooleanClause(right, BooleanClause.Occur.SHOULD)); return new ConstantScoreQuery(q.build()); } else { return newBoxInternal(field, lower, upper); } } private static Query newBoxInternal(String field, byte[] min, byte[] max) { return new PointRangeQuery(field, min, max, 2) { @Override protected String toString(int dimension, byte[] value) { if (dimension == 0) { return Double.toString(decodeLatitude(value, 0)); } else if (dimension == 1) { return Double.toString(decodeLongitude(value, 0)); } else { throw new AssertionError(); } } }; } /** * Create a query for matching points within the specified distance of the supplied location. * @param field field name. must not be null. * @param latitude latitude at the center: must be within standard +/-90 coordinate bounds. * @param longitude longitude at the center: must be within standard +/-180 coordinate bounds. * @param radiusMeters maximum distance from the center in meters: must be non-negative and finite. * @return query matching points within this distance * @throws IllegalArgumentException if {@code field} is null, location has invalid coordinates, or radius is invalid. */ public static Query newDistanceQuery(String field, double latitude, double longitude, double radiusMeters) { return new LatLonPointDistanceQuery(field, latitude, longitude, radiusMeters); } /** * Create a query for matching one or more polygons. * @param field field name. must not be null. * @param polygons array of polygons. must not be null or empty * @return query matching points within this polygon * @throws IllegalArgumentException if {@code field} is null, {@code polygons} is null or empty * @see Polygon */ public static Query newPolygonQuery(String field, Polygon... polygons) { return new LatLonPointInPolygonQuery(field, polygons); } /** * Given a field that indexes point values into a {@link LatLonPoint} * and doc values into {@link LatLonDocValuesField}, this returns a query that scores * documents based on their haversine distance in meters to {@code (originLat, originLon)}: * {@code score = weight * pivotDistanceMeters / (pivotDistanceMeters + distance)}, ie. * score is in the {@code [0, weight]} range, is equal to {@code weight} when * the document's value is equal to {@code (originLat, originLon)} and is equal to * {@code weight/2} when the document's value is distant of * {@code pivotDistanceMeters} from {@code (originLat, originLon)}. * In case of multi-valued fields, only the closest point to {@code (originLat, originLon)} * will be considered. * This query is typically useful to boost results based on distance by adding * this query to a {@link Occur#SHOULD} clause of a {@link BooleanQuery}. */ public static Query newDistanceFeatureQuery(String field, float weight, double originLat, double originLon, double pivotDistanceMeters) { Query query = new LatLonPointDistanceFeatureQuery(field, originLat, originLon, pivotDistanceMeters); if (weight != 1f) { query = new BoostQuery(query, weight); } return query; } }