XPathSearchPlugin.java :  » Blogger-System » blojsom-3.1 » org » blojsom » plugin » xpath » Java Open Source

/**
 * Copyright (c) 2003-2007, David A. Czarnecki
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this list of conditions and the
 *     following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 *     following disclaimer in the documentation and/or other materials provided with the distribution.
 * Neither the name of "David A. Czarnecki" and "blojsom" nor the names of its contributors may be used to
 *     endorse or promote products derived from this software without specific prior written permission.
 * Products derived from this software may not be called "blojsom", nor may "blojsom" appear in their name,
 *     without prior written permission of David A. Czarnecki.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.blojsom.plugin.xpath;

import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.blojsom.blog.Entry;
import org.blojsom.blog.Blog;
import org.blojsom.plugin.PluginException;
import org.blojsom.plugin.search.SimpleSearchPlugin;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * XPathSearchPlugin
 *
 * @author David Czarnecki
 * @author Mark Lussier
 * @since blojsom 3.0
 * @version $Id: XPathSearchPlugin.java,v 1.2 2007/01/17 02:35:07 czarneckid Exp $
 */
public class XPathSearchPlugin extends SimpleSearchPlugin {

    private Log _logger = LogFactory.getLog(XPathSearchPlugin.class);

    /**
     * Process the blog entries
     *
     * @param httpServletRequest  Request
     * @param httpServletResponse Response
     * @param blog                {@link Blog} instance
     * @param context             Context
     * @param entries             Blog entries retrieved for the particular request
     * @return Modified set of blog entries
     * @throws PluginException If there is an error processing the blog entries
     */
    public Entry[] process(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Blog blog, Map context, Entry[] entries) throws PluginException {
        Entry[] results;

        String query = httpServletRequest.getParameter(QUERY_PARAM);

        if (query != null) {
            query = query.trim();
            if (query.startsWith("/")) {
                if (_logger.isDebugEnabled()) {
                    _logger.debug("Attempting xpath query with: " + query);
                }

                EntryWrapper entryWrapper = new EntryWrapper(entries);
                List foundEntries = new ArrayList();
                JXPathContext xpathcontext = JXPathContext.newContext(entryWrapper);
                try {
                    Iterator entryIterator = xpathcontext.iterate(query);
                    while (entryIterator.hasNext()) {
                        Object object = entryIterator.next();
                        Entry entry = (Entry) object;
                        foundEntries.add(entry);
                    }
                } catch (Exception e) {
                    if (_logger.isErrorEnabled()) {
                        _logger.error(e);
                    }
                }

                if (foundEntries.size() == 0) {
                    results = new Entry[0];
                } else {
                    results = new Entry[foundEntries.size()];
                    for (int x = 0; x < foundEntries.size(); x++) {
                        results[x] = (Entry) foundEntries.get(x);
                    }
                }
            } else {
                results = super.process(httpServletRequest, httpServletResponse, blog, context, entries);
            }
        } else {
            results = entries;
        }

        return results;
    }
}