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 java.io.IOException; import org.apache.lucene.index.DocValues; import org.apache.lucene.index.DocValuesType; import org.apache.lucene.index.LeafReader; import org.apache.lucene.index.NumericDocValues; import org.apache.lucene.index.SortedNumericDocValues; import org.apache.lucene.search.IndexOrDocValuesQuery; import org.apache.lucene.search.Query; /** * <p> * Field that stores a per-document <code>long</code> value for scoring, * sorting or value retrieval. Here's an example usage: * * <pre class="prettyprint"> * document.add(new NumericDocValuesField(name, 22L)); * </pre> * * <p> * If you also need to store the value, you should add a * separate {@link StoredField} instance. * */ public class NumericDocValuesField extends Field { /** * Type for numeric DocValues. */ public static final FieldType TYPE = new FieldType(); static { TYPE.setDocValuesType(DocValuesType.NUMERIC); TYPE.freeze(); } /** * Creates a new DocValues field with the specified 64-bit long value * @param name field name * @param value 64-bit long value * @throws IllegalArgumentException if the field name is null */ public NumericDocValuesField(String name, long value) { this(name, Long.valueOf(value)); } /** * Creates a new DocValues field with the specified 64-bit long value * @param name field name * @param value 64-bit long value or <code>null</code> if the existing fields value should be removed on update * @throws IllegalArgumentException if the field name is null */ public NumericDocValuesField(String name, Long value) { super(name, TYPE); fieldsData = value; } /** * Create a range query that matches all documents whose value is between * {@code lowerValue} and {@code upperValue} included. * <p> * You can have half-open ranges (which are in fact </≤ or >/≥ queries) * by setting {@code lowerValue = Long.MIN_VALUE} or {@code upperValue = Long.MAX_VALUE}. * <p> * Ranges are inclusive. For exclusive ranges, pass {@code Math.addExact(lowerValue, 1)} * or {@code Math.addExact(upperValue, -1)}. * <p><b>NOTE</b>: Such queries cannot efficiently advance to the next match, * which makes them slow if they are not ANDed with a selective query. As a * consequence, they are best used wrapped in an {@link IndexOrDocValuesQuery}, * alongside a range query that executes on points, such as * {@link LongPoint#newRangeQuery}. */ public static Query newSlowRangeQuery(String field, long lowerValue, long upperValue) { return new SortedNumericDocValuesRangeQuery(field, lowerValue, upperValue) { @Override SortedNumericDocValues getValues(LeafReader reader, String field) throws IOException { NumericDocValues values = reader.getNumericDocValues(field); if (values == null) { return null; } return DocValues.singleton(values); } }; } /** * Create a query for matching an exact long value. * <p><b>NOTE</b>: Such queries cannot efficiently advance to the next match, * which makes them slow if they are not ANDed with a selective query. As a * consequence, they are best used wrapped in an {@link IndexOrDocValuesQuery}, * alongside a range query that executes on points, such as * {@link LongPoint#newExactQuery}. */ public static Query newSlowExactQuery(String field, long value) { return newSlowRangeQuery(field, value, value); } }