in morfologik-addon/src/main/java/opennlp/morfologik/lemmatizer/MorfologikLemmatizer.java [77:93]
public String lemmatize(String word, String postag) {
String lemma;
List<String> keys = this.getDictKeys(word, postag);
HashMap<List<String>, String> dictMap = this.getDictMap(word, postag);
// lookup lemma as value of the map
String keyValue = dictMap.get(keys);
if (keyValue != null) {
lemma = keyValue;
} else if (keyValue == null && constantTags.contains(postag)) {
lemma = word;
} else if (keyValue == null && word.toUpperCase().equals(word)) {
lemma = word;
} else {
lemma = word.toLowerCase();
}
return lemma;
}