Package opennlp.tools.stemmer

Class PorterStemmer

  • All Implemented Interfaces:
    Stemmer
    public class PorterStemmer
extends Object
implements Stemmer
    A Stemmer, implementing the Porter Stemming Algorithm

    The Stemmer implementation transforms a word into its root form. The input word can be provided a character at time (by calling add(char)), or at once by calling one of the various stem(..) methods.

    • Constructor Summary

      Constructors 
      Constructor Description
      PorterStemmer()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(char ch)
      Add a character to the word being stemmed.
      char[] getResultBuffer()
      Returns a reference to a character buffer containing the results of the stemming process.
      int getResultLength()
      Returns the length of the word resulting from the stemming process.
      void reset()
      reset() resets the stemmer so it can stem another word.
      boolean stem()
      Stem the word placed into the Stemmer buffer through calls to add().
      boolean stem​(char[] word)
      Stem a word contained in a char[].
      boolean stem​(char[] word, int wordLen)
      Stem a word contained in a leading portion of a char[] array.
      boolean stem​(char[] wordBuffer, int offset, int wordLen)
      Stem a word contained in a portion of a char[] array.
      boolean stem​(int i0)  
      CharSequence stem​(CharSequence word)
      Stem a word provided as a CharSequence.
      String stem​(String s)
      Stem a word provided as a String.
      String toString()
      After a word has been stemmed, it can be retrieved by toString(), or a reference to the internal buffer can be retrieved by getResultBuffer and getResultLength (which is generally more efficient.)

    • Constructor Detail

      • PorterStemmer

        public PorterStemmer()

    • Method Detail

      • reset

        public void reset()
        reset() resets the stemmer so it can stem another word. If you invoke the stemmer by calling add(char) and then stem(), you must call reset() before starting another word.

      • add

        public void add​(char ch)
        Add a character to the word being stemmed. When you are finished adding characters, you can call stem(void) to process the word.

      • toString

        public String toString()
        After a word has been stemmed, it can be retrieved by toString(), or a reference to the internal buffer can be retrieved by getResultBuffer and getResultLength (which is generally more efficient.)
        Overrides:
        toString in class Object

      • getResultLength

        public int getResultLength()
        Returns the length of the word resulting from the stemming process.

      • getResultBuffer

        public char[] getResultBuffer()
        Returns a reference to a character buffer containing the results of the stemming process. You also need to consult getResultLength() to determine the length of the result.

      • stem

        public String stem​(String s)
        Stem a word provided as a String. Returns the result as a String.

      • stem

        public CharSequence stem​(CharSequence word)
        Stem a word provided as a CharSequence. Returns the result as a CharSequence.
        Specified by:
        stem in interface Stemmer

      • stem

        public boolean stem​(char[] word)
        Stem a word contained in a char[]. Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

      • stem

        public boolean stem​(char[] wordBuffer,
                    int offset,
                    int wordLen)
        Stem a word contained in a portion of a char[] array. Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

      • stem

        public boolean stem​(char[] word,
                    int wordLen)
        Stem a word contained in a leading portion of a char[] array. Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

      • stem

        public boolean stem()
        Stem the word placed into the Stemmer buffer through calls to add(). Returns true if the stemming process resulted in a word different from the input. You can retrieve the result with getResultLength()/getResultBuffer() or toString().

      • stem

        public boolean stem​(int i0)