Lucene Porter Stemmer不公开

Question

How to use the Porter Stemmber class in Lucene 3.6.2? Here is what I have:

import org.apache.lucene.analysis.PorterStemmer;
...
PorterStemmer stemmer = new PorterStemmer();
term = stemmer.stem(term);

I am being told: PorterStemmer is not public in org.apache.lucene.analysis; cannot be accessed from outside package.

Edit: I also read extensively about using Snowball, but it isn't encouraged. What is the right way to stem using Lucene in Java??

Answer 1

1) If you want to use PorterStemmer as part of Lucene token analysis process, use PorterStemFilter

Sample code

 class MyAnalyzer extends Analyzer {
  public final TokenStream tokenStream(String fieldName, Reader reader) {
    return new PorterStemFilter(new LowerCaseTokenizer(reader));
  }
 }

---

2) If you want to use PorterStemmer just for any other application, here is the sourcecode by author himself: PorterStemmer in Java

Answer 2

In Lucene later version, PorterStemmer no longer public. So

 class MyAnalyzer extends Analyzer {
   public final TokenStream tokenStream(String fieldName, Reader reader) {
    return new PorterStemFilter(new LowerCaseTokenizer(reader));
   }
   }

Or you can use SnowballAnalyzer Stemmer. link (SnowballAnalyzer is deprecated)

import org.tartarus.snowball.ext.PorterStemmer;
.
.
public static  String applyPorterStemmer(String input) throws IOException {

        PorterStemmer stemmer = new PorterStemmer();
        stemmer.setCurrent(input);
        stemmer.stem();
        return stemmer.getCurrent();
    }