com.sshtools.common.mru.MRUList.java Source code

Introduction

Here is the source code for com.sshtools.common.mru.MRUList.java

Source

//Changes (c) CCLRC 2006
/*
 *  SSHTools - Java SSH2 API
 *
 *  Copyright (C) 2002 Lee David Painter.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *
 *  You may also distribute it and/or modify it under the terms of the
 *  Apache style J2SSH Software License. A copy of which should have
 *  been provided with the distribution.
 *
 *  This program 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
 *  License document supplied with your distribution for more details.
 *
 */

package com.sshtools.common.mru;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.Stack;
import java.util.Vector;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 *
 *
 * @author $author$
 * @version $Revision: 1.6 $
 */
public class MRUList extends java.util.Vector {
    private static Log log = LogFactory.getLog(MRUList.class);
    private static final String MRU_LIST_ELEMENT = "MRUList";
    private static final String FILE_ELEMENT = "File";
    private String currentElement = null;

    /**
     * Creates a new MRUList object.
     */
    public MRUList() {
        super();
    }

    /**
     * Creates a new MRUList object.
     *
     * @param in
     *
     * @throws SAXException
     * @throws ParserConfigurationException
     * @throws IOException
     */
    public MRUList(InputStream in) throws SAXException, ParserConfigurationException, IOException {
        this();
        reload(in);
    }

    /**
     *
     *
     * @param in
     *
     * @throws SAXException
     * @throws ParserConfigurationException
     * @throws IOException
     */
    public void reload(InputStream in) throws SAXException, ParserConfigurationException, IOException {
        try {
            SAXParserFactory saxFactory = SAXParserFactory.newInstance();
            SAXParser saxParser = saxFactory.newSAXParser();
            saxParser.parse(in, new MRUSAXHandler());
        } catch (Throwable e) {
            System.out.println("MRUList.reload: Exception loading most-recently-used list.");
            e.printStackTrace();
        }
    }

    /**
     *
     *
     * @return
     */
    public String toString() {
        String xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
        xml += ("<!-- Most recently used -->\n<" + MRU_LIST_ELEMENT + ">\n");

        Iterator it = iterator();
        File file = null;

        while (it.hasNext()) {
            file = (File) it.next();
            xml += ("   " + "<" + FILE_ELEMENT + ">" + file.getAbsolutePath() + "</" + FILE_ELEMENT + ">\n");
        }

        xml += ("</" + MRU_LIST_ELEMENT + ">");

        return xml;
    }

    private class MRUSAXHandler extends DefaultHandler {
        private String MRU_LIST_ELEMENT = "MRUList";
        private String FILE_ELEMENT = "File";
        private File currentFile = null;
        private Stack tags = new Stack();

        public void startElement(String uri, String localName, String qname, Attributes attrs) throws SAXException {
            ElementWrapper currentElement = (tags.size() == 0) ? null : (ElementWrapper) tags.peek();

            if (currentElement == null) {
                if (!qname.equals(MRU_LIST_ELEMENT)) {
                    throw new SAXException("Unexpected root element <" + qname + ">");
                }
            } else {
                if (currentElement.element.equals(MRU_LIST_ELEMENT)) {
                    if (qname.equals(FILE_ELEMENT)) {
                    } else {
                        throw new SAXException("Unexpected element <" + qname + ">");
                    }
                } else {
                    throw new SAXException("Unexpected element <" + qname + ">");
                }
            }

            ElementWrapper w = new ElementWrapper(qname);
            tags.push(w);
        }

        public void characters(char[] ch, int start, int len) throws SAXException {
            ElementWrapper currentElement = (tags.size() == 0) ? null : (ElementWrapper) tags.peek();

            if (currentElement != null) {
                currentElement.text.append(new String(ch, start, len));
            } else {
                throw new SAXException("Unexpected text at " + start + " for " + len);
            }
        }

        public void endElement(String uri, String localName, String qname) throws SAXException {
            ElementWrapper currentElement = (tags.size() == 0) ? null : (ElementWrapper) tags.peek();

            if (currentElement != null) {
                if (!currentElement.element.equals(qname)) {
                    throw new SAXException("Unexpected end element found <" + qname + ">");
                }

                if (currentElement.element.equals(FILE_ELEMENT)) {
                    MRUList.this.add(new File(currentElement.text.toString()));
                }

                tags.pop();
            }
        }
    }

    public class ElementWrapper {
        String element;
        StringBuffer text;

        ElementWrapper(String element) {
            this.element = element;
            text = new StringBuffer();
        }
    }
}