/** * JWAP - A Java Implementation of the WAP Protocols * Copyright (C) 2001-2004 Niko Bender * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */package net.sourceforge.jwap.wsp.header;import java.util.Enumeration;import java.util.Properties;import java.util.StringTokenizer;import java.util.Vector;/** * Helper class for tokenizing header fields. A HeaderToken consists of a token value * and optional parameters. * <p> * <b>Example usage</b> * <pre> * for( Enumeration e = HeaderToken.tokenize("en; q=0.8, fr; q=0.2"); e.hasMoreElements(); ) * { *   HeaderToken ht = (HeaderToken) e.nextElement(); *   String token = token.getToken(); // "en" for first iteration, "fr" for second iteration *   String qval = token.getParameter("q"); // "0.8" for first iteration, "0.2" for second iteration * } * </pre> * * @author Michel Marti * */public class HeaderToken {    private static final Enumeration EMPTY_ENUM = new Vector().elements();    private String token;    private Properties parameters;    private HeaderToken(String token) {        parameters = new Properties();        this.token = token.trim();    }    /**     * Returns an enumeration of HeaderToken objects by tokenizing the specified     * String.     *     * @param value a header field     * @return an enumeration of HeaderToken's     */    public static Enumeration tokenize(String value) {        if (value == null) {            return EMPTY_ENUM;        }        value=value.trim();        Vector v = new Vector();                if( value.equals("") ) {          v.add(new HeaderToken(""));          return v.elements();        }                StringTokenizer strtok = new StringTokenizer(value, ",");        while (strtok.hasMoreTokens()) {            String token = strtok.nextToken();            StringTokenizer st2 = new StringTokenizer(token, ";");            token = st2.nextToken();            HeaderToken ht = new HeaderToken(token);            v.add(ht);            while (st2.hasMoreTokens()) {                String param = st2.nextToken();                String key;                String val;                int p = param.indexOf("=");                if (p > 0) {                    key = param.substring(0, p);                    val = param.substring(p + 1);                } else {                    key = param;                    val = "";                }                ht.addParameter(key.toLowerCase(), val);            }        }        return v.elements();    }    public String getParameter(String key) {        return parameters.getProperty(key);    }    public boolean hasParameters() {        return parameters.size() > 0;    }    public String getToken() {        return token;    }    public String toString() {        StringBuffer sb = new StringBuffer();        sb.append(token).append("=").append(parameters);        return sb.toString();    }    private void addParameter(String key, String value) {        parameters.put(key.trim(), value.trim());    }}