org.apache.lucene.analysis.fr: public final class: FrenchStemFilter

org.apache.lucene.analysis.fr
public final class: FrenchStemFilter [javadoc | source]

java.lang.Object
   org.apache.lucene.analysis.TokenStream
      org.apache.lucene.analysis.TokenFilter
         org.apache.lucene.analysis.fr.FrenchStemFilter

A filter that stemms french words. It supports a table of words that should not be stemmed at all. The used stemmer can be changed at runtime after the filter object is created (as long as it is a FrenchStemmer).

author: Patrick - Talbot (based on Gerhard Schwarz work for German)

Fields inherited from org.apache.lucene.analysis.TokenFilter:
input

Constructor:
public FrenchStemFilter(TokenStream in) { super(in); stemmer = new FrenchStemmer(); }
public FrenchStemFilter(TokenStream in, Set exclusiontable) { this( in ); exclusions = exclusiontable; }

Constructor:

 public FrenchStemFilter(TokenStream in) {
	     
    super(in);
		stemmer = new FrenchStemmer();
}

 public FrenchStemFilter(TokenStream in,
    Set exclusiontable) {
		this( in );
		exclusions = exclusiontable;
}

Method from org.apache.lucene.analysis.fr.FrenchStemFilter Summary:
next, setExclusionTable, setStemmer

Methods from org.apache.lucene.analysis.TokenFilter:
close

Methods from org.apache.lucene.analysis.TokenStream:
close, next, next, reset

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.apache.lucene.analysis.fr.FrenchStemFilter Detail:
public final Token next() throws IOException { if ( ( token = input.next() ) == null ) { return null; } // Check the exclusiontable else if ( exclusions != null && exclusions.contains( token.termText() ) ) { return token; } else { String s = stemmer.stem( token.termText() ); // If not stemmed, dont waste the time creating a new token if ( !s.equals( token.termText() ) ) { return new Token( s, token.startOffset(), token.endOffset(), token.type()); } return token; } }
public void setExclusionTable(Hashtable exclusiontable) { exclusions = new HashSet(exclusiontable.keySet()); } Set an alternative exclusion list for this filter.
public void setStemmer(FrenchStemmer stemmer) { if ( stemmer != null ) { this.stemmer = stemmer; } } Set a alternative/custom FrenchStemmer for this filter.

Method from org.apache.lucene.analysis.fr.FrenchStemFilter Detail:

 public final Token next() throws IOException {
		if ( ( token = input.next() ) == null ) {
			return null;
		}
		// Check the exclusiontable
		else if ( exclusions != null && exclusions.contains( token.termText() ) ) {
			return token;
		}
		else {
			String s = stemmer.stem( token.termText() );
			// If not stemmed, dont waste the time creating a new token
			if ( !s.equals( token.termText() ) ) {
			   return new Token( s, token.startOffset(), token.endOffset(), token.type());
			}
			return token;
		}
}

 public  void setExclusionTable(Hashtable exclusiontable) {
		exclusions = new HashSet(exclusiontable.keySet());
}

Set an alternative exclusion list for this filter.

 public  void setStemmer(FrenchStemmer stemmer) {
		if ( stemmer != null ) {
			this.stemmer = stemmer;
		}
}

Set a alternative/custom FrenchStemmer for this filter.