thumbelina.java

html 解析处理代码

// HTMLParser Library $Name: v1_6 $ - A java-based parser for HTML
// http://sourceforge.org/projects/htmlparser
// Copyright (C) 2003 Derrick Oswald
//
// Revision Control Information
//
// $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/lexerapplications/thumbelina/Thumbelina.java,v $
// $Author: derrickoswald $
// $Date: 2005/02/13 20:36:00 $
// $Revision: 1.7 $
//
// 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 org.htmlparser.lexerapplications.thumbelina;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Image;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.ImageObserver;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;

import javax.swing.BoxLayout;
import javax.swing.DefaultListModel;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.JSplitPane;
import javax.swing.JTextField;
import javax.swing.ListSelectionModel;
import javax.swing.ScrollPaneConstants;
import javax.swing.border.BevelBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

import org.htmlparser.Node;
import org.htmlparser.Tag;
import org.htmlparser.lexer.Lexer;
import org.htmlparser.util.ParserException;

/**
 * View images behind thumbnails.
 */
public class Thumbelina
    extends
        JPanel // was: java.awt.Canvas
    implements
        Runnable,
        ItemListener,
        ChangeListener,
        ListSelectionListener
{
    /**
     * Property name for current URL binding.
     */
    public static final String PROP_CURRENT_URL_PROPERTY = "currentURL";
    /**
     * Property name for queue size binding.
     */
    public static final String PROP_URL_QUEUE_PROPERTY = "queueSize";
    /**
     * Property name for visited URL size binding.
     */
    public static final String PROP_URL_VISITED_PROPERTY = "visitedSize";

    /**
     * URL's to visit.
     */
    private ArrayList mUrls;

    /**
     * URL's visited.
     */
    protected HashMap mVisited;

    /**
     * Images requested.
     */
    protected HashMap mRequested;

    /**
     * Images being tracked currently.
     */
    protected HashMap mTracked;

    /**
     * Background thread.
     */
    protected Thread mThread;

    /**
     * Activity state.
     * <code>true</code> means processing URLS, <code>false</code> not.
     */
    protected boolean mActive;

    /**
     * The picture sequencer.
     */
    protected Sequencer mSequencer;

    /**
     * The central area for pictures.
     */
    protected PicturePanel mPicturePanel;

    /**
     * Value returned when no links are discovered.
     */
    protected static final URL[][] NONE = { { }, { } };

    /**
     * Bound property support.
     */
    protected PropertyChangeSupport mPropertySupport;

    /**
     * The URL being currently being examined.
     */
    protected String mCurrentURL;

    /**
     * If <code>true</code>, does not follow links containing cgi calls.
     */
    protected boolean mDiscardCGI;

    /**
     * If <code>true</code>, does not follow links containing queries (?).
     */
    protected boolean mDiscardQueries;

    /**
     * Background thread checkbox in status bar.
     */
    protected JCheckBox mBackgroundToggle;

    /**
     * History list.
     */
    protected JList mHistory;

    /**
     * Scroller for the picture panel.
     */
    protected JScrollPane mPicturePanelScroller;

    /**
     * Scroller for the history list.
     */
    protected JScrollPane mHistoryScroller;

    /**
     * Main panel in central area.
     */
    protected JSplitPane mMainArea;

    /**
     * Status bar.
     */
    protected JPanel mPowerBar;

    /**
     * Image request queue monitor in status bar.
     */
    protected JProgressBar mQueueProgress;

    /**
     * Image ready queue monitor in status bar.
     */
    protected JProgressBar mReadyProgress;

    /**
     * Sequencer thread toggle in status bar.
     */
    protected JCheckBox mRunToggle;

    /**
     * Sequencer speed slider in status bar.
     */
    protected JSlider mSpeedSlider;

    /**
     * URL report in status bar.
     */
    protected JTextField mUrlText;

    /**
     * URL queue size display in status bar.
     */
    protected JLabel mQueueSize;

    /**
     * URL visited count display in status bar.
     */
    protected JLabel mVisitedSize;

    /**
     * Creates a new instance of Thumbelina.
     */
    public Thumbelina ()
    {
        this ((URL)null);
    }

    /**
     * Creates a new instance of Thumbelina.
     * @param url Single URL to enter into the 'to follow' list.
     * @exception MalformedURLException If the url is malformed.
     */
    public Thumbelina (final String url)
        throws
            MalformedURLException
    {
        this (null == url ? null : new URL (url));
    }

    /**
     * Creates a new instance of Thumbelina.
     * @param url URL to enter into the 'to follow' list.
     */
    public Thumbelina (final URL url)
    {
        mUrls = new ArrayList ();
        mVisited = new HashMap ();
        mRequested = new HashMap ();
        mTracked = new HashMap ();
        mThread = null;
        mActive = true;
        mPicturePanel = new PicturePanel (this);
        mSequencer = new Sequencer (this);
        mPropertySupport = new PropertyChangeSupport (this);
        mCurrentURL = null;
        mDiscardCGI = true;
        mDiscardQueries = true;

        // JComponent specific
        setDoubleBuffered (false);
        setLayout (new java.awt.BorderLayout ());
        mPicturePanel.setDoubleBuffered (false);

        mThread = new Thread (this);
        mThread.setName ("BackgroundThread");
        mThread.start ();
        initComponents ();

        mRunToggle.addItemListener (this);
        mBackgroundToggle.addItemListener (this);
        mSpeedSlider.addChangeListener (this);
        mHistory.addListSelectionListener (this);

        memCheck ();

        if (null != url)
            append (url);
    }

    /**
     * Check for low memory situation.
     * Report to the user a bad situation.
     */
    protected void memCheck ()
    {
        Runtime runtime;
        long maximum;

        if (System.getProperty ("java.version").startsWith ("1.4"))
        {
            runtime = Runtime.getRuntime ();
            runtime.gc ();
            maximum = runtime.maxMemory ();
            if (maximum < 67108864L) // 64MB
                JOptionPane.showMessageDialog (
                    null,
                    "Maximum available memory is low (" + maximum + " bytes).\n"
                    + "\n"
                    + "It is strongly suggested to increase the maximum memory\n"
                    + "available by using the JVM command line switch -Xmx with\n"
                    + "a suitable value, such as -Xmx256M for example.",
                    "Thumbelina - Low memory",
                    JOptionPane.WARNING_MESSAGE,
                    null /*Icon*/);
        }
    }

    /**
     * Reset this Thumbelina.
     * Clears the sequencer of pending images, resets the picture panel,
     * emptiies the 'to be examined' list of URLs.
     */
    public void reset ()
    {
        int oldsize;

        synchronized (mUrls)
        {
            mSequencer.reset ();
            mPicturePanel.reset ();
            oldsize = mUrls.size ();
            mUrls.clear ();
        }
        updateQueueSize (oldsize, mUrls.size ());
    }

    /**
     * Append the given URL to the queue.
     * Adds the url only if it isn't already in the queue,
     * and notifys listeners about the addition.
     * @param url The url to add.
     */
    public void append (final URL url)
    {
        String href;
        boolean found;
        URL u;
        int oldsize;

        href = url.toExternalForm ();
        found = false;
        oldsize = -1;
        synchronized (mUrls)
        {
            for (int i = 0; !found && (i < mUrls.size ()); i++)
            {
                u = (URL)mUrls.get (i);
                if (href.equals (u.toExternalForm ()))
                    found = true;
            }
            if (!found)
            {
                oldsize = mUrls.size ();
                mUrls.add (url);
                mUrls.notify ();
            }
        }
        if (-1 != oldsize)
            updateQueueSize (oldsize, mUrls.size ());
    }

    /**
     * Append the given URLs to the queue.
     * @param list The list of URL objects to add.
     */
    public void append (final ArrayList list)
    {