org.apache.lucene.analysis
Class PerFieldAnalyzerWrapper

java.lang.Object
  extended byorg.apache.lucene.analysis.Analyzer
      extended byorg.apache.lucene.analysis.PerFieldAnalyzerWrapper

public class PerFieldAnalyzerWrapper
extends Analyzer

This analyzer is used to facilitate scenarios where different fields require different analysis techniques. Use addAnalyzer(java.lang.String, org.apache.lucene.analysis.Analyzer) to add a non-default analyzer on a field name basis.

Example usage:

   PerFieldAnalyzerWrapper aWrapper =
      new PerFieldAnalyzerWrapper(new StandardAnalyzer());
   aWrapper.addAnalyzer("firstname", new KeywordAnalyzer());
   aWrapper.addAnalyzer("lastname", new KeywordAnalyzer());
 

In this example, StandardAnalyzer will be used for all fields except "firstname" and "lastname", for which KeywordAnalyzer will be used.

A PerFieldAnalyzerWrapper can be used like any other analyzer, for both indexing and query parsing.


Constructor Summary
PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer)
          Constructs with default analyzer.
 
Method Summary
 void addAnalyzer(String fieldName, Analyzer analyzer)
          Defines an analyzer to use for the specified field.
 int getPositionIncrementGap(String fieldName)
          Return the positionIncrementGap from the analyzer assigned to fieldName
 TokenStream tokenStream(String fieldName, Reader reader)
          Creates a TokenStream which tokenizes all the text in the provided Reader.
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

PerFieldAnalyzerWrapper

public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer)
Constructs with default analyzer.

Parameters:
defaultAnalyzer - Any fields not specifically defined to use a different analyzer will use the one provided here.
Method Detail

addAnalyzer

public void addAnalyzer(String fieldName,
                        Analyzer analyzer)
Defines an analyzer to use for the specified field.

Parameters:
fieldName - field name requiring a non-default analyzer
analyzer - non-default analyzer to use for field

tokenStream

public TokenStream tokenStream(String fieldName,
                               Reader reader)
Description copied from class: Analyzer
Creates a TokenStream which tokenizes all the text in the provided Reader. Default implementation forwards to tokenStream(Reader) for compatibility with older version. Override to allow Analyzer to choose strategy based on document and/or field. Must be able to handle null field name for backward compatibility.

Specified by:
tokenStream in class Analyzer

getPositionIncrementGap

public int getPositionIncrementGap(String fieldName)
Return the positionIncrementGap from the analyzer assigned to fieldName

Overrides:
getPositionIncrementGap in class Analyzer
Parameters:
fieldName - Fieldable name being indexed.
Returns:
position increment gap, added to the next token emitted from Analyzer.tokenStream(String,Reader)

toString

public String toString()


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