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 the Map
30
* argument in {@link #PerFieldAnalyzerWrapper(Analyzer, java.util.Map)}
31
* to add non-default analyzers for fields.
36
* Map analyzerPerField = new HashMap();
37
* analyzerPerField.put("firstname", new KeywordAnalyzer());
38
* analyzerPerField.put("lastname", new KeywordAnalyzer());
40
* PerFieldAnalyzerWrapper aWrapper =
41
* new PerFieldAnalyzerWrapper(new StandardAnalyzer(), analyzerPerField);
44
* <p>In this example, StandardAnalyzer will be used for all fields except "firstname"
45
* and "lastname", for which KeywordAnalyzer will be used.
47
* <p>A PerFieldAnalyzerWrapper can be used like any other analyzer, for both indexing
50
public final class PerFieldAnalyzerWrapper extends Analyzer {
51
private final Analyzer defaultAnalyzer;
52
private final Map<String,Analyzer> analyzerMap = new HashMap<String,Analyzer>();
56
* Constructs with default analyzer.
58
* @param defaultAnalyzer Any fields not specifically
59
* defined to use a different analyzer will use the one provided here.
61
public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer) {
62
this(defaultAnalyzer, null);
66
* Constructs with default analyzer and a map of analyzers to use for
69
* @param defaultAnalyzer Any fields not specifically
70
* defined to use a different analyzer will use the one provided here.
71
* @param fieldAnalyzers a Map (String field name to the Analyzer) to be
72
* used for those fields
74
public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer,
75
Map<String,Analyzer> fieldAnalyzers) {
76
this.defaultAnalyzer = defaultAnalyzer;
77
if (fieldAnalyzers != null) {
78
analyzerMap.putAll(fieldAnalyzers);
84
* Defines an analyzer to use for the specified field.
86
* @param fieldName field name requiring a non-default analyzer
87
* @param analyzer non-default analyzer to use for field
88
* @deprecated Changing the Analyzer for a field after instantiation prevents
89
* reusability. Analyzers for fields should be set during construction.
92
public void addAnalyzer(String fieldName, Analyzer analyzer) {
93
analyzerMap.put(fieldName, analyzer);
97
public TokenStream tokenStream(String fieldName, Reader reader) {
98
Analyzer analyzer = analyzerMap.get(fieldName);
99
if (analyzer == null) {
100
analyzer = defaultAnalyzer;
103
return analyzer.tokenStream(fieldName, reader);
107
public TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException {
108
Analyzer analyzer = analyzerMap.get(fieldName);
109
if (analyzer == null)
110
analyzer = defaultAnalyzer;
112
return analyzer.reusableTokenStream(fieldName, reader);
115
/** Return the positionIncrementGap from the analyzer assigned to fieldName */
117
public int getPositionIncrementGap(String fieldName) {
118
Analyzer analyzer = analyzerMap.get(fieldName);
119
if (analyzer == null)
120
analyzer = defaultAnalyzer;
121
return analyzer.getPositionIncrementGap(fieldName);
124
/** Return the offsetGap from the analyzer assigned to field */
126
public int getOffsetGap(Fieldable field) {
127
Analyzer analyzer = analyzerMap.get(field.name());
128
if (analyzer == null)
129
analyzer = defaultAnalyzer;
130
return analyzer.getOffsetGap(field);
134
public String toString() {
135
return "PerFieldAnalyzerWrapper(" + analyzerMap + ", default=" + defaultAnalyzer + ")";