org.dlese.dpc.index.analysis
Class PerFieldAnalyzer

java.lang.Object
  org.apache.lucene.analysis.Analyzer
      org.dlese.dpc.index.analysis.PerFieldAnalyzer

All Implemented Interfaces:

Closeable

public class PerFieldAnalyzer
extends org.apache.lucene.analysis.Analyzer

This Analyzer is used to facilitate scenarios where different fields require different analysis techniques. Use #addAnalyzer to add a non-default Analyzer or addAnalyzersInBundle(java.util.ResourceBundle) to provide a ResourceBundle to configure Analyzers on a field name basis. The ResourceBundle should contain className=field1,field2,... pairs, where the field names are a comma-separated list, for example:

org.dlese.dpc.index.analysis.SnowballAnalyzer=stems,titlestems

Author:

John Weatherley

Field Summary

static String	KEYWORD_ANALYZER
static String	STEMS_ANALYZER
static String	TEXT_ANALYZER

Fields inherited from class org.apache.lucene.analysis.Analyzer

overridesTokenStreamMethod

Constructor Summary

PerFieldAnalyzer()
Constructs using a StandardAnalyzer as the default for fields not otherwise configured.

PerFieldAnalyzer(org.apache.lucene.analysis.Analyzer defaultAnalyzer)
Constructs with the given Analyzer to use as a default for fields not otherwise configured.

Method Summary

void	addAnalyzersInBundle(ResourceBundle fieldAnalyzerBundle) Adds the Analyzers to use for given fields, using the field=className pairs provided in the ResourceBundle, overrridding any previous ones if they existed.
boolean	containsAnalyzer(String fieldName) Determines if an Analyzer is configured for the given field.
org.apache.lucene.analysis.Analyzer	getAnalyzer(String fieldName) Gets the Analyzer configured for the given field, or null if none exists.
org.apache.lucene.analysis.Analyzer	getDefaultAnalyzer() Gets the default Analyzer being used.
org.apache.lucene.analysis.Analyzer	removeAnalyzer(String fieldName) Removes the Analyzer that is configured for the given field, if one exists.
void	setAnalyzer(String fieldName, String analyzerClassName) Sets the Analyzer to use for the specified search field, overridding the previous one if it existed.
void	setDefaultAnalyzer(org.apache.lucene.analysis.Analyzer analyzer) Sets the default Analyzer to use from here forth.
org.apache.lucene.analysis.TokenStream	tokenStream(String fieldName, Reader reader) Generates a token stream for the given field.
String	toString()

Methods inherited from class org.apache.lucene.analysis.Analyzer

close, getOffsetGap, getPositionIncrementGap, getPreviousTokenStream, reusableTokenStream, setOverridesTokenStreamMethod, setPreviousTokenStream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

TEXT_ANALYZER

public static final String TEXT_ANALYZER

See Also:

Constant Field Values

KEYWORD_ANALYZER

public static final String KEYWORD_ANALYZER

See Also:

Constant Field Values

STEMS_ANALYZER

public static final String STEMS_ANALYZER

See Also:

Constant Field Values

Constructor Detail

PerFieldAnalyzer

public PerFieldAnalyzer(org.apache.lucene.analysis.Analyzer defaultAnalyzer)

Constructs with the given Analyzer to use as a default for fields not otherwise configured. If null, a StandardAnalyzer will be used as the default.

Parameters:

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

PerFieldAnalyzer

public PerFieldAnalyzer()

Constructs using a StandardAnalyzer as the default for fields not otherwise configured.

Method Detail

setAnalyzer

public void setAnalyzer(String fieldName,
                        String analyzerClassName)
                 throws ClassNotFoundException,
                        InstantiationException,
                        IllegalAccessException

Sets the Analyzer to use for the specified search field, overridding the previous one if it existed.

Parameters:

fieldName - field name requiring a non-default analyzer.

analyzerClassName - Name of Analyzer class to use for the field

Throws:

ClassNotFoundException - If error

InstantiationException - If error

IllegalAccessException - If error

toString

public String toString()

Overrides:

toString in class Object

addAnalyzersInBundle

public void addAnalyzersInBundle(ResourceBundle fieldAnalyzerBundle)
                          throws ClassNotFoundException,
                                 InstantiationException,
                                 IllegalAccessException

Adds the Analyzers to use for given fields, using the field=className pairs provided in the ResourceBundle, overrridding any previous ones if they existed. The ResourceBundle should contain className=field1,field2,... pairs, where the field names are a comma-separated list, for example:

org.dlese.dpc.index.analysis.SnowballAnalyzer=stems,titlestems

Parameters:

fieldAnalyzerBundle - A resource bundle containing className=field1,field2,etc. pairs

Throws:

ClassNotFoundException - If error

InstantiationException - If error

IllegalAccessException - If error

getAnalyzer

public org.apache.lucene.analysis.Analyzer getAnalyzer(String fieldName)

Gets the Analyzer configured for the given field, or null if none exists.

Parameters:

fieldName - The field name

Returns:

The Analyzer

getDefaultAnalyzer

public org.apache.lucene.analysis.Analyzer getDefaultAnalyzer()

Gets the default Analyzer being used.

Returns:

The default Analyzer

setDefaultAnalyzer

public void setDefaultAnalyzer(org.apache.lucene.analysis.Analyzer analyzer)

Sets the default Analyzer to use from here forth.

Parameters:

analyzer - The new default Analyzer

containsAnalyzer

public boolean containsAnalyzer(String fieldName)

Determines if an Analyzer is configured for the given field.

Parameters:

fieldName - The field name

Returns:

True if an Analyzer is configured for the given field

removeAnalyzer

public org.apache.lucene.analysis.Analyzer removeAnalyzer(String fieldName)

Removes the Analyzer that is configured for the given field, if one exists. After removing, the given will will use the default Analyzer.

Parameters:

fieldName - The field name

Returns:

The Analyzer that was configured, or null

tokenStream

public org.apache.lucene.analysis.TokenStream tokenStream(String fieldName,
                                                          Reader reader)

Generates a token stream for the given field.

Specified by:

tokenStream in class org.apache.lucene.analysis.Analyzer

Parameters:

fieldName - The field name

reader - The Reader

Returns:

The TokenStream appropriate for this field