directivefactory.java

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/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*  notice, this list of conditions and the following disclaimer.
*
*  2. Redistributions in binary form must reproduce the above copyright
*  notice, this list of conditions and the following disclaimer in
*  the documentation and/or other materials provided with the
*  distribution.
*
*  3. The end-user documentation included with the redistribution,
*  if any, must include the following acknowledgment:
*  "This product includes software developed by the
*  Sun Microsystems, Inc. for Project JXTA."
*  Alternately, this acknowledgment may appear in the software itself,
*  if and wherever such third-party acknowledgments normally appear.
*
*  4. The groups "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
*  must not be used to endorse or promote products derived from this
*  software without prior written permission. For written
*  permission, please contact Project JXTA at http://www.jxta.org.
*
*  5. Products derived from this software may not be called "JXTA",
*  nor may "JXTA" appear in their group, without prior written
*  permission of Sun.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*  SUCH DAMAGE.
*  ====================================================================
*
*  This software consists of voluntary contributions made by many
*  individuals on behalf of Project JXTA.  For more
*  information on Project JXTA, please see
*  <http://www.jxta.org/>.
*
*  This license is based on the BSD license adopted by the Apache Foundation.
*
*  $Id: DirectiveFactory.java,v 1.8 2007/05/23 21:00:18 nano Exp $
*/

package net.jxta.myjxta.directive;

import net.jxta.myjxta.dialog.DialogMessage;
import net.jxta.myjxta.dialog.util.Text;
import net.jxta.myjxta.util.Group;

import java.io.IOException;
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.logging.Logger;

/**
 * @author james todd [gonzo at jxta dot org]
 * @version $Id: DirectiveFactory.java,v 1.8 2007/05/23 21:00:18 nano Exp $
 */

public class DirectiveFactory {

    private static final char DELIMITER = '.';
    private static final String DIRECTIVES = "directives";
    private static final String BASE =
            DirectiveFactory.class.getPackage().getName() + DELIMITER +
                    DIRECTIVES + DELIMITER;

    private static final Logger LOG = Logger.getLogger(Directive.class.getName());

    public static Directive get(DialogMessage msg, Group g)
            throws ClassNotFoundException {
        Directive d = null;
        String ds = msg != null ? clean(msg.getHtmlMessage()) : null;

        if (ds.length() > 0 &&
                ds.charAt(0) == Directive.INDICATOR) {
            List<String> pd = parse(ds);

            if (pd.size() > 0) {
                String id = pd.get(0);

                id = id != null ? id.trim() : id;

                if (id != null &&
                        id.length() > 0) {
                    try {
                        d = (Directive) Class.forName(BASE + id).newInstance();
                    } catch (InstantiationException ie) {
                        LOG.log(java.util.logging.Level.SEVERE,
                                "Caught unexpected Exception", ie);
                    } catch (IllegalAccessException iae) {
                        LOG.log(java.util.logging.Level.SEVERE,
                                "Caught unexpected Exception", iae);
                    }
                }

                d.setId(pd.get(0));
                d.setGroup(g);
                d.setArgs(pd.size() > 1 ?
                        pd.subList(1, pd.size()) : Collections.EMPTY_LIST);
            }
        }

        return d;
    }

    private static List<String> parse(String directive) {
        List<String> args = new ArrayList<String>();
        StreamTokenizer st =
                new StreamTokenizer(new StringReader(directive.trim()));

        st.wordChars('!', '~');
        st.ordinaryChar(Directive.INDICATOR);
        st.whitespaceChars('\t', '\t');
        st.whitespaceChars('\r', '\r');
        st.whitespaceChars(' ', ' ');

        try {
            while (st.nextToken() != StreamTokenizer.TT_EOF) {
                if (st.ttype == StreamTokenizer.TT_WORD) {
                    args.add(st.sval);
                } else if (st.ttype == StreamTokenizer.TT_NUMBER) {
                    args.add(String.valueOf(st.nval));
                }
            }
        } catch (IOException ioe) {
            LOG.log(java.util.logging.Level.SEVERE, "Caught unexpected Exception",
                    ioe);
        }

        return args;
    }

    private static String clean(String s) {
        return Text.replace(Text.replace(s, Text.MARKUP, Text.EMPTY).trim(),
                Text.PREAMBLE, Text.EMPTY);
    }
}