CodePlugin.java

// 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: CodePlugin.java,v 1.2 2007/05/03 13:53:34 spyromus Exp $
//

package com.salas.bb.plugins.domain;

import com.salas.bb.utils.StringUtils;
import org.jdom.Element;

import java.util.Map;

/**
 * A plug-in based on Java code.
 */
public class CodePlugin
{
    /**
     * Creates a code plug-in if it's possible.
     *
     * @param element   XML element to parse.
     * @param loader    loader to use.
     *
     * @return a plug-in or <code>NULL</code>.
     *
     * @throws LoaderException if something wrong happens.
     */
    public static ICodePlugin create(Element element, ClassLoader loader)
        throws LoaderException
    {
        // Get class name
        String className = element.getAttributeValue("class");
        if (StringUtils.isEmpty(className)) throw new LoaderException("Class name isn't specified");

        // Load class
        Class<ICodePlugin> clazz;
        try
        {
            clazz = (Class<ICodePlugin>)loader.loadClass(className);
        } catch (ClassNotFoundException e)
        {
            throw new LoaderException("Failed to find class " + className + " in the plug-in package");
        }


        // Create instance and initialize
        ICodePlugin pl;
        try
        {
            pl = clazz.newInstance();
            pl.setPackageLoader(loader);

            Map<String,String> props = PluginUtils.getPluginProperties(element);
            pl.setParameters(props);
        } catch (Exception e)
        {
            throw new LoaderException("Failed to create an instance of " + className, e);
        }

        return pl;
    }
}