heppletagger.java

dragontoolkit用于机器学习

package dragon.nlp.tool;

import dragon.nlp.*;
import dragon.util.*;
import hepple.postag.*;
import java.util.*;
import java.io.File;

/**
 * <p>Hepple tagger adopted from hepple.postag </p>
 * <p> </p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */

public class HeppleTagger extends AbstractTagger implements Tagger {
    private POSTagger tag;

    public HeppleTagger(){
        this(EnvVariable.getDragonHome()+"/nlpdata/tagger");
    }

    public HeppleTagger(String workDir) {
        try{
            if(!FileUtil.exist(workDir) && FileUtil.exist(EnvVariable.getDragonHome()+"/"+workDir))
                workDir=EnvVariable.getDragonHome()+"/"+workDir;
			tag = new POSTagger(new File(workDir+"/lexicon_all").toURL(),new File(workDir+"/rules_cap").toURL());
            if(tag==null)
            {
                System.out.println("Failed to create POS tagger");
            }
		}
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    public void tag(Sentence sent){
        String[] output;
        List result, sentenceForTagger, sentencesForTagger;
        int i;

        sentenceForTagger = new ArrayList();
        sentencesForTagger = new ArrayList(1);
        sentencesForTagger.add(sentenceForTagger);
        Word word=sent.getFirstWord();
        while (word != null) {
            sentenceForTagger.add(word.getContent());
            word = word.next;
        }
        result=(List)tag.runTagger(sentencesForTagger);
        if(result.size()<=0) return;

        result=(List)result.get(0);
        word=sent.getFirstWord();
        for(i=0;i<result.size();i++)
        {
            output=(String[])result.get(i);
            word.setPOS(output[1], getPOSIndex(output[1],word));
            word=word.next;
        }

    }
    
    protected int getPOSIndex(String pos, Word word) {
        int posIndex;

        if (word.isPunctuation()) {
            pos = word.getContent();
            posIndex = 0;
        }
        else if (pos.startsWith("N")) {
            posIndex = HeppleTagger.POS_NOUN;
        }
        else if (pos.startsWith("VB")) {
            posIndex = Tagger.POS_VERB;
        }
        else if (pos.startsWith("JJ")) {
            posIndex = Tagger.POS_ADJECTIVE;
        }
        else if (pos.startsWith("RB")) {
            posIndex = Tagger.POS_ADVERB;
        }
        else if (pos.startsWith("CC")) {
            posIndex = Tagger.POS_CC;
        }
        else if (pos.startsWith("DT")) {
            posIndex = Tagger.POS_DT;
        }
        else if (pos.startsWith("PRP")) {
            posIndex = Tagger.POS_PRONOUN;
        }
        else if (pos.startsWith("IN")) {
            if (isConjunction(word.getContent())) {
                posIndex = Tagger.POS_CC;
            }
            else {
                posIndex = Tagger.POS_IN;
            }
        }
        else if (pos.startsWith("TO")) {
            posIndex = Tagger.POS_IN;
        }
        else if (pos.startsWith("CD")) {
            if (word.isNumber()) {
                posIndex = Tagger.POS_NUM;
            }
            else {
                posIndex = Tagger.POS_NOUN;
            }
        }
        else if (pos.startsWith("W")) {
            posIndex = Tagger.POS_CC;
        }
        else {
            posIndex = 0;
        }

        if(posIndex>0 && posIndex!=Tagger.POS_NOUN && word.isAllCapital()){
            posIndex=Tagger.POS_NOUN;
        }
        return posIndex;
    }
}