/*
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.
*/
using System;
namespace Lucene.Net.Analysis{
/// <summary> This analyzer is used to facilitate scenarios where different
/// fields require different analysis techniques. Use {@link #addAnalyzer}
/// to add a non-default analyzer on a field name basis.
///
/// <p>Example usage:
///
/// <pre>
/// PerFieldAnalyzerWrapper aWrapper =
/// new PerFieldAnalyzerWrapper(new StandardAnalyzer());
/// aWrapper.addAnalyzer("firstname", new KeywordAnalyzer());
/// aWrapper.addAnalyzer("lastname", new KeywordAnalyzer());
/// </pre>
///
/// <p>In this example, StandardAnalyzer will be used for all fields except "firstname"
/// and "lastname", for which KeywordAnalyzer will be used.
///
/// <p>A PerFieldAnalyzerWrapper can be used like any other analyzer, for both indexing
/// and query parsing.
/// </summary>
public class PerFieldAnalyzerWrapper:Analyzer
{
private Analyzer defaultAnalyzer;
private System.Collections.IDictionary analyzerMap = new System.Collections.Hashtable();
/// <summary> Constructs with default analyzer.
///
/// </summary>
/// <param name="defaultAnalyzer">Any fields not specifically
/// defined to use a different analyzer will use the one provided here.
/// </param>
public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer)
{
this.defaultAnalyzer = defaultAnalyzer;
}
/// <summary> Defines an analyzer to use for the specified field.
///
/// </summary>
/// <param name="fieldName">field name requiring a non-default analyzer
/// </param>
/// <param name="analyzer">non-default analyzer to use for field
/// </param>
public virtual void AddAnalyzer(System.String fieldName, Analyzer analyzer)
{
analyzerMap[fieldName] = analyzer;
}
public override TokenStream TokenStream(System.String fieldName, System.IO.TextReader reader)
{
Analyzer analyzer = (Analyzer) analyzerMap[fieldName];
if (analyzer == null)
{
analyzer = defaultAnalyzer;
}
return analyzer.TokenStream(fieldName, reader);
}
public override System.String ToString()
{
// {{Aroush-1.9}} 'analyzerMap.ToString()' may return a different value then Java.
return "PerFieldAnalyzerWrapper(" + analyzerMap.ToString() + ", default=" + defaultAnalyzer + ")";
}
}
}
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