tokenizer.java

Practical AI in Java 人工智能编程

import java.io.StreamTokenizer;
import java.io.StringReader;
import java.io.Reader;
import java.util.Vector;


public class Tokenizer {
    static public Vector getTokens(String ss) throws Exception {
        return getTokens(new StringReader(ss));
    }

    static public Vector getTokens(Reader reader) throws Exception {
        Vector words = new Vector();
        StreamTokenizer str_tok = new StreamTokenizer(reader);
        while (str_tok.nextToken() !=
                StreamTokenizer.TT_EOF) {
            String s;
            switch (str_tok.ttype) {
                case StreamTokenizer.TT_EOL:
                    s = ""; // ignore this
                    break;
                case StreamTokenizer.TT_WORD:
                    s = str_tok.sval;
                    break;
                case StreamTokenizer.TT_NUMBER:
                    s = ""; // ignore this
                    break;
                default:
                    s = String.valueOf((char) str_tok.ttype);
            }
            if (s.startsWith("$")) continue;
            if (s.indexOf("-") > -1) continue;
            s = s.toLowerCase();
            s = s.replace('"', ' ').replace('%', ' ').replace('(', ' ');
            s = s.replace(')', ' ').replace('\'', ' ');
            s = s.trim();
            if (s.indexOf(" ") != -1) continue;
            if (s.endsWith(".")) {
                s = s.substring(0, s.length() - 1);
            } else if (s.endsWith(",")) {
                s = s.substring(0, s.length() - 1);
            } else if (s.endsWith(";")) {
                s = s.substring(0, s.length() - 1);
            } else if (s.endsWith(":")) {
                s = s.substring(0, s.length() - 1);
            }

            if (s.length() < 2) continue;
            if (s.indexOf(".") > -1) continue;
            if (s.indexOf("0") > -1) continue;
            if (s.indexOf("1") > -1) continue;
            if (s.indexOf("2") > -1) continue;
            if (s.indexOf("3") > -1) continue;
            if (s.indexOf("4") > -1) continue;
            if (s.indexOf("5") > -1) continue;
            if (s.indexOf("6") > -1) continue;
            if (s.indexOf("7") > -1) continue;
            if (s.indexOf("8") > -1) continue;
            if (s.indexOf("9") > -1) continue;

            words.add(s.toLowerCase());

        }
        return words;
    }
}