public class CustomStemmingPreprocessor
extends CommonPreprocessor

This is StemmingPreprocessor compatible with different StemmingProcessors defined as lucene/tartarus SnowballProgram such as: RussianStemmer, DutchStemmer, FrenchStemmer etc.
Note that CommonPreprocessor#preProcess(String) is first applied (i.e. punctuation marks are removed and lower-cased), then the stemmer is applied.
This preprocessor is synchronized, thus thread-safe.