org.apache.lucene.document.IntField Maven / Gradle / Ivy
package org.apache.lucene.document;
/*
* 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.
*/
import org.apache.lucene.analysis.NumericTokenStream; // javadocs
import org.apache.lucene.index.IndexOptions;
import org.apache.lucene.search.NumericRangeQuery; // javadocs
import org.apache.lucene.util.NumericUtils;
/**
*
* Field that indexes int values
* for efficient range filtering and sorting. Here's an example usage:
*
*
* document.add(new IntField(name, 6, Field.Store.NO));
*
*
* For optimal performance, re-use the IntField and
* {@link Document} instance for more than one document:
*
*
* IntField field = new IntField(name, 6, Field.Store.NO);
* Document document = new Document();
* document.add(field);
*
* for(all documents) {
* ...
* field.setIntValue(value)
* writer.addDocument(document);
* ...
* }
*
*
* See also {@link LongField}, {@link FloatField}, {@link
* DoubleField}.
*
* To perform range querying or filtering against a
* IntField, use {@link NumericRangeQuery}.
* To sort according to a
* IntField, use the normal numeric sort types, eg
* {@link org.apache.lucene.search.SortField.Type#INT}. IntField
* values can also be loaded directly from {@link org.apache.lucene.index.LeafReader#getNumericDocValues}.
*
* You may add the same field name as an IntField to
* the same document more than once. Range querying and
* filtering will be the logical OR of all values; so a range query
* will hit all documents that have at least one value in
* the range. However sort behavior is not defined. If you need to sort,
* you should separately index a single-valued IntField.
*
* An IntField will consume somewhat more disk space
* in the index than an ordinary single-valued field.
* However, for a typical index that includes substantial
* textual content per document, this increase will likely
* be in the noise.
*
* Within Lucene, each numeric value is indexed as a
* trie structure, where each term is logically
* assigned to larger and larger pre-defined brackets (which
* are simply lower-precision representations of the value).
* The step size between each successive bracket is called the
* precisionStep, measured in bits. Smaller
* precisionStep values result in larger number
* of brackets, which consumes more disk space in the index
* but may result in faster range search performance. The
* default value, 8, was selected for a reasonable tradeoff
* of disk space consumption versus performance. You can
* create a custom {@link FieldType} and invoke the {@link
* FieldType#setNumericPrecisionStep} method if you'd
* like to change the value. Note that you must also
* specify a congruent value when creating {@link
* NumericRangeQuery}.
* For low cardinality fields larger precision steps are good.
* If the cardinality is < 100, it is fair
* to use {@link Integer#MAX_VALUE}, which produces one
* term per value.
*
*
For more information on the internals of numeric trie
* indexing, including the precisionStep
* configuration, see {@link NumericRangeQuery}. The format of
* indexed values is described in {@link NumericUtils}.
*
*
If you only need to sort by numeric value, and never
* run range querying/filtering, you can index using a
* precisionStep of {@link Integer#MAX_VALUE}.
* This will minimize disk space consumed.
*
* More advanced users can instead use {@link
* NumericTokenStream} directly, when indexing numbers. This
* class is a wrapper around this token stream type for
* easier, more intuitive usage.
*
* @since 2.9
*/
public final class IntField extends Field {
/**
* Type for an IntField that is not stored:
* normalization factors, frequencies, and positions are omitted.
*/
public static final FieldType TYPE_NOT_STORED = new FieldType();
static {
TYPE_NOT_STORED.setTokenized(true);
TYPE_NOT_STORED.setOmitNorms(true);
TYPE_NOT_STORED.setIndexOptions(IndexOptions.DOCS);
TYPE_NOT_STORED.setNumericType(FieldType.NumericType.INT);
TYPE_NOT_STORED.setNumericPrecisionStep(NumericUtils.PRECISION_STEP_DEFAULT_32);
TYPE_NOT_STORED.freeze();
}
/**
* Type for a stored IntField:
* normalization factors, frequencies, and positions are omitted.
*/
public static final FieldType TYPE_STORED = new FieldType();
static {
TYPE_STORED.setTokenized(true);
TYPE_STORED.setOmitNorms(true);
TYPE_STORED.setIndexOptions(IndexOptions.DOCS);
TYPE_STORED.setNumericType(FieldType.NumericType.INT);
TYPE_STORED.setNumericPrecisionStep(NumericUtils.PRECISION_STEP_DEFAULT_32);
TYPE_STORED.setStored(true);
TYPE_STORED.freeze();
}
/** Creates a stored or un-stored IntField with the provided value
* and default precisionStep {@link
* NumericUtils#PRECISION_STEP_DEFAULT_32} (8).
* @param name field name
* @param value 32-bit integer value
* @param stored Store.YES if the content should also be stored
* @throws IllegalArgumentException if the field name is null.
*/
public IntField(String name, int value, Store stored) {
super(name, stored == Store.YES ? TYPE_STORED : TYPE_NOT_STORED);
fieldsData = Integer.valueOf(value);
}
/** Expert: allows you to customize the {@link
* FieldType}.
* @param name field name
* @param value 32-bit integer value
* @param type customized field type: must have {@link FieldType#numericType()}
* of {@link FieldType.NumericType#INT}.
* @throws IllegalArgumentException if the field name or type is null, or
* if the field type does not have a INT numericType()
*/
public IntField(String name, int value, FieldType type) {
super(name, type);
if (type.numericType() != FieldType.NumericType.INT) {
throw new IllegalArgumentException("type.numericType() must be INT but got " + type.numericType());
}
fieldsData = Integer.valueOf(value);
}
}