Package org.apache.lucene.analysis.de

Class GermanStemFilter

  • All Implemented Interfaces:
    Closeable, AutoCloseable
    public final class GermanStemFilter
extends org.apache.lucene.analysis.TokenFilter
    A TokenFilter that stems German words.

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

    To prevent terms from being stemmed use an instance of KeywordMarkerFilter or a custom TokenFilter that sets the KeywordAttribute before this TokenStream.

    See Also:
    KeywordMarkerFilter

    • Nested Class Summary

      • Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

        org.apache.lucene.util.AttributeSource.AttributeFactory, org.apache.lucene.util.AttributeSource.State

    • Field Summary

      • Fields inherited from class org.apache.lucene.analysis.TokenFilter

        input

    • Constructor Summary

      Constructors 
      Constructor Description
      GermanStemFilter​(org.apache.lucene.analysis.TokenStream in)
      Creates a GermanStemFilter instance
      GermanStemFilter​(org.apache.lucene.analysis.TokenStream in, Set<?> exclusionSet)
      Deprecated.
      use KeywordAttribute with KeywordMarkerFilter instead.

    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      boolean incrementToken()  
      void setExclusionSet​(Set<?> exclusionSet)
      Deprecated.
      use KeywordAttribute with KeywordMarkerFilter instead.
      void setStemmer​(GermanStemmer stemmer)
      Set a alternative/custom GermanStemmer for this filter.

      • Methods inherited from class org.apache.lucene.analysis.TokenFilter

        close, end, reset

      • Methods inherited from class org.apache.lucene.util.AttributeSource

        addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString

    • Constructor Detail

      • GermanStemFilter

        public GermanStemFilter​(org.apache.lucene.analysis.TokenStream in)
        Creates a GermanStemFilter instance
        Parameters:
        in - the source TokenStream

      • GermanStemFilter

        @Deprecated
public GermanStemFilter​(org.apache.lucene.analysis.TokenStream in,
                        Set<?> exclusionSet)
        Deprecated.
        use KeywordAttribute with KeywordMarkerFilter instead.
        Builds a GermanStemFilter that uses an exclusion table.

    • Method Detail

      • incrementToken

        public boolean incrementToken()
                       throws IOException
        Specified by:
        incrementToken in class org.apache.lucene.analysis.TokenStream
        Returns:
        Returns true for next token in the stream, or false at EOS
        Throws:
        IOException

      • setExclusionSet

        @Deprecated
public void setExclusionSet​(Set<?> exclusionSet)
        Deprecated.
        use KeywordAttribute with KeywordMarkerFilter instead.
        Set an alternative exclusion list for this filter.