1 package org.apache.lucene.analysis;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
20 import org.apache.lucene.document.Fieldable;
22 import java.io.Reader;
23 import java.io.IOException;
25 import java.util.HashMap;
28 * This analyzer is used to facilitate scenarios where different
29 * fields require different analysis techniques. Use {@link #addAnalyzer}
30 * to add a non-default analyzer on a field name basis.
35 * PerFieldAnalyzerWrapper aWrapper =
36 * new PerFieldAnalyzerWrapper(new StandardAnalyzer());
37 * aWrapper.addAnalyzer("firstname", new KeywordAnalyzer());
38 * aWrapper.addAnalyzer("lastname", new KeywordAnalyzer());
41 * <p>In this example, StandardAnalyzer will be used for all fields except "firstname"
42 * and "lastname", for which KeywordAnalyzer will be used.
44 * <p>A PerFieldAnalyzerWrapper can be used like any other analyzer, for both indexing
47 public final class PerFieldAnalyzerWrapper extends Analyzer {
48 private Analyzer defaultAnalyzer;
49 private Map<String,Analyzer> analyzerMap = new HashMap<String,Analyzer>();
53 * Constructs with default analyzer.
55 * @param defaultAnalyzer Any fields not specifically
56 * defined to use a different analyzer will use the one provided here.
58 public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer) {
59 this(defaultAnalyzer, null);
63 * Constructs with default analyzer and a map of analyzers to use for
66 * @param defaultAnalyzer Any fields not specifically
67 * defined to use a different analyzer will use the one provided here.
68 * @param fieldAnalyzers a Map (String field name to the Analyzer) to be
69 * used for those fields
71 public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer,
72 Map<String,Analyzer> fieldAnalyzers) {
73 this.defaultAnalyzer = defaultAnalyzer;
74 if (fieldAnalyzers != null) {
75 analyzerMap.putAll(fieldAnalyzers);
81 * Defines an analyzer to use for the specified field.
83 * @param fieldName field name requiring a non-default analyzer
84 * @param analyzer non-default analyzer to use for field
86 public void addAnalyzer(String fieldName, Analyzer analyzer) {
87 analyzerMap.put(fieldName, analyzer);
91 public TokenStream tokenStream(String fieldName, Reader reader) {
92 Analyzer analyzer = analyzerMap.get(fieldName);
93 if (analyzer == null) {
94 analyzer = defaultAnalyzer;
97 return analyzer.tokenStream(fieldName, reader);
101 public TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException {
102 Analyzer analyzer = analyzerMap.get(fieldName);
103 if (analyzer == null)
104 analyzer = defaultAnalyzer;
106 return analyzer.reusableTokenStream(fieldName, reader);
109 /** Return the positionIncrementGap from the analyzer assigned to fieldName */
111 public int getPositionIncrementGap(String fieldName) {
112 Analyzer analyzer = analyzerMap.get(fieldName);
113 if (analyzer == null)
114 analyzer = defaultAnalyzer;
115 return analyzer.getPositionIncrementGap(fieldName);
118 /** Return the offsetGap from the analyzer assigned to field */
120 public int getOffsetGap(Fieldable field) {
121 Analyzer analyzer = analyzerMap.get(field.name());
122 if (analyzer == null)
123 analyzer = defaultAnalyzer;
124 return analyzer.getOffsetGap(field);
128 public String toString() {
129 return "PerFieldAnalyzerWrapper(" + analyzerMap + ", default=" + defaultAnalyzer + ")";