// HTMLParser Library $Name: v1_6_20060319 $ - A java-based parser for HTML
// http://sourceforge.org/projects/htmlparser
// Copyright (C) 2004 Derrick Oswald
//
// Revision Control Information
//
// $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/beans/LinkBean.java,v $
// $Author: derrickoswald $
// $Date: 2005/05/15 11:49:03 $
// $Revision: 1.32 $
//
// 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.beans;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.Serializable;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Vector;
import org.htmlparser.NodeFilter;
import org.htmlparser.Parser;
import org.htmlparser.filters.NodeClassFilter;
import org.htmlparser.tags.LinkTag;
import org.htmlparser.util.EncodingChangeException;
import org.htmlparser.util.NodeList;
import org.htmlparser.util.ParserException;
/**
* Extract links from a URL.
*/
public class LinkBean extends Object implements Serializable
{
/**
* Property name in event where the URL contents changes.
*/
public static final String PROP_LINKS_PROPERTY = "links";
/**
* Property name in event where the URL changes.
*/
public static final String PROP_URL_PROPERTY = "URL";
/**
* Bound property support.
*/
protected PropertyChangeSupport mPropertySupport;
/**
* The strings extracted from the URL.
*/
protected URL[] mLinks;
/**
* The parser used to extract strings.
*/
protected Parser mParser;
/** Creates new LinkBean */
public LinkBean ()
{
mPropertySupport = new PropertyChangeSupport (this);
mLinks = null;
mParser = new Parser ();
}
//
// internals
//
/**
* Internal routine to extract all the links from the parser.
* @return A list of all links on the page as URLs.
* @exception ParserException If the parse fails.
*/
protected URL[] extractLinks () throws ParserException
{
NodeFilter filter;
NodeList list;
Vector vector;
LinkTag link;
URL[] ret;
mParser.reset ();
filter = new NodeClassFilter (LinkTag.class);
try
{
list = mParser.extractAllNodesThatMatch (filter);
}
catch (EncodingChangeException ece)
{
mParser.reset ();
list = mParser.extractAllNodesThatMatch (filter);
}
vector = new Vector();
for (int i = 0; i < list.size (); i++)
try
{
link = (LinkTag)list.elementAt (i);
vector.add(new URL (link.getLink ()));
}
catch (MalformedURLException murle)
{
//vector.remove (i);
//i--;
}
ret = new URL[vector.size ()];
vector.copyInto (ret);
return (ret);
}
/**
* Determine if two arrays of URL's are the same.
* @param array1 One array of URL's
* @param array2 Another array of URL's
* @return <code>true</code> if the URL's match in number and value,
* <code>false</code> otherwise.
*/
protected boolean equivalent (URL[] array1, URL[] array2)
{
boolean ret;
ret = false;
if ((null == array1) && (null == array2))
ret = true;
else if ((null != array1) && (null != array2))
if (array1.length == array2.length)
{
ret = true;
for (int i = 0; i < array1.length && ret; i++)
if (!(array1[i] == array2[i]))
ret = false;
}
return (ret);
}
//
// Property change support.
//
/**
* Add a PropertyChangeListener to the listener list.
* The listener is registered for all properties.
* @param listener The PropertyChangeListener to be added.
*/
public void addPropertyChangeListener (PropertyChangeListener listener)
{
mPropertySupport.addPropertyChangeListener (listener);
}
/**
* Remove a PropertyChangeListener from the listener list.
* This removes a registered PropertyChangeListener.
* @param listener The PropertyChangeListener to be removed.
*/
public void removePropertyChangeListener (PropertyChangeListener listener)
{
mPropertySupport.removePropertyChangeListener (listener);
}
//
// Properties
//
/**
* Refetch the URL contents.
*/
private void setLinks ()
{
String url;
URL[] urls;
URL[] oldValue;
url = getURL ();
if (null != url)
try
{
urls = extractLinks ();
if (!equivalent (mLinks, urls))
{
oldValue = mLinks;
mLinks = urls;
mPropertySupport.firePropertyChange (
PROP_LINKS_PROPERTY, oldValue, mLinks);
}
}
catch (ParserException hpe)
{
mLinks = null;
}
}
/**
* Getter for property links.
* @return Value of property links.
*/
public URL[] getLinks ()
{
if (null == mLinks)
try
{
mLinks = extractLinks ();
mPropertySupport.firePropertyChange (
PROP_LINKS_PROPERTY, null, mLinks);
}
catch (ParserException hpe)
{
mLinks = null;
}
return (mLinks);
}
/**
* Getter for property URL.
* @return Value of property URL.
*/
public String getURL ()
{
return (mParser.getURL ());
}
/**
* Setter for property URL.
* @param url New value of property URL.
*/
public void setURL (String url)
{
String old;
old = getURL ();
if (((null == old) && (null != url)) || ((null != old)
&& !old.equals (url)))
{
try
{
mParser.setURL (url);
mPropertySupport.firePropertyChange (
PROP_URL_PROPERTY, old, getURL ());
setLinks ();
}
catch (ParserException hpe)
{
// failed... now what
}
}
}
/**
* Getter for property Connection.
* @return Value of property Connection.
*/
public URLConnection getConnection ()
{
return (mParser.getConnection ());
}
/**
* Setter for property Connection.
* @param connection New value of property Connection.
*/
public void setConnection (URLConnection connection)
{
try
{
mParser.setConnection (connection);
setLinks ();
}
catch (ParserException hpe)
{
// failed... now what
}
}
/**
* Unit test.
* @param args Pass arg[0] as the URL to process.
*/
public static void main (String[] args)
{
if (0 >= args.length)
System.out.println ("Usage: java -classpath htmlparser.jar"
+ " org.htmlparser.beans.LinkBean <http://whatever_url>");
else
{
LinkBean lb = new LinkBean ();
lb.setURL (args[0]);
URL[] urls = lb.getLinks ();
for (int i = 0; i < urls.length; i++)
System.out.println (urls[i]);
}
}
}