// BlogBridge -- RSS feed reader, manager, and web based service
// Copyright (C) 2002-2006 by R. Pito Salas
//
// This program is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software Foundation;
// either version 2 of the License, or (at your option) any later version.
//
// 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 GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with this program;
// if not, write to the Free Software Foundation, Inc., 59 Temple Place,
// Suite 330, Boston, MA 02111-1307 USA
//
// Contact: R. Pito Salas
// mailto:pitosalas@users.sourceforge.net
// More information: about BlogBridge
// http://www.blogbridge.com
// http://sourceforge.net/projects/blogbridge
//
// $Id $
//
package com.salas.bb.discovery.filter;
import com.jgoodies.binding.beans.PropertyAdapter;
import com.salas.bb.utils.StringUtils;
import java.util.regex.Pattern;
import java.util.List;
import java.util.ArrayList;
/**
* Dynamic extension URL filter watches the changes in some property of
* some bean object and recompiles the pattern every time it's necessary.
*/
public class DynamicExtensionURLFilter extends ExtensionURLFilter
{
private PropertyAdapter adapter;
private Pattern pattern;
private int extendsionsHash;
private final Object patternLock = new Object();
/**
* Creates extension URL filter with dynamic list.
*
* @param bean bean to watch for the list.
* @param propertyName the name of the property holding the list of extensions.
*/
public DynamicExtensionURLFilter(Object bean, String propertyName)
{
super((String[])null);
if (bean == null) throw new NullPointerException("Bean should be specified");
if (propertyName == null) throw new NullPointerException("Property name should be specified");
adapter = new PropertyAdapter(bean, propertyName);
}
/**
* Returns the pattern to use for matching.
*
* @return pattern.
*/
protected Pattern getPattern()
{
// Calculate current extensions hash code
Object val = adapter.getValue();
String ext = val == null ? null : val.toString().trim();
int hash = ext == null ? 0 : ext.hashCode();
// Check if the codes differ -- if the extensions list has changed
if (extendsionsHash != hash)
{
synchronized (patternLock)
{
if (extendsionsHash != hash)
{
// Recalculate the pattern
String[] extensions = stringToExtensions(ext);
String patternStr = extensionsToPattern(extensions);
pattern = patternStr == null ? null : Pattern.compile(patternStr, Pattern.CASE_INSENSITIVE);
extendsionsHash = hash;
}
}
}
return pattern;
}
}