/**
* Copyright (c) 2003-2005, David A. Czarnecki
* All rights reserved.
*
* Portions Copyright (c) 2003-2005 by Mark Lussier
*
* 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 the "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.pingback;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.xmlrpc.AsyncCallback;
import org.apache.xmlrpc.XmlRpcClient;
import org.blojsom.blog.BlogEntry;
import org.blojsom.blog.BlogUser;
import org.blojsom.blog.BlojsomConfiguration;
import org.blojsom.event.BlojsomEvent;
import org.blojsom.event.BlojsomListener;
import org.blojsom.plugin.BlojsomPlugin;
import org.blojsom.plugin.BlojsomPluginException;
import org.blojsom.plugin.admin.event.AddBlogEntryEvent;
import org.blojsom.plugin.admin.event.BlogEntryEvent;
import org.blojsom.plugin.admin.event.UpdatedBlogEntryEvent;
import org.blojsom.util.BlojsomConstants;
import org.blojsom.util.BlojsomUtils;
import javax.servlet.ServletConfig;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Map;
import java.util.Vector;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Pingback plugin implements a pingback client to send pingbacks to any URLs in a blog entry according to the
* Pingback 1.0 specification.
*
* @author David Czarnecki
* @version $Id: PingbackPlugin.java,v 1.1.2.1 2005/07/21 04:30:37 johnan Exp $
* @since blojsom 2.24
*/
public class PingbackPlugin implements BlojsomPlugin, BlojsomListener, BlojsomConstants {
private static Log _logger = LogFactory.getLog(PingbackPlugin.class);
private static final String PINGBACK_METHOD = "pingback.ping";
private static final String X_PINGBACK_HEADER = "X-Pingback";
private static final String PINGBACK_LINK_REGEX = "";
private static final String HREF_REGEX = "href\\s*=\\s*\"(.*?)\"";
public static final String PINGBACK_PLUGIN_METADATA_SEND_PINGBACKS = "send-pingbacks";
private PingbackPluginAsyncCallback _callbackHandler;
/**
* Create a new instance of the Pingback plugin
*/
public PingbackPlugin() {
}
/**
* Initialize this plugin. This method only called when the plugin is instantiated.
*
* @param servletConfig Servlet config object for the plugin to retrieve any initialization parameters
* @param blojsomConfiguration {@link org.blojsom.blog.BlojsomConfiguration} information
* @throws org.blojsom.plugin.BlojsomPluginException
* If there is an error initializing the plugin
*/
public void init(ServletConfig servletConfig, BlojsomConfiguration blojsomConfiguration) throws BlojsomPluginException {
_callbackHandler = new PingbackPluginAsyncCallback();
blojsomConfiguration.getEventBroadcaster().addListener(this);
_logger.debug("Initialized pingback plugin");
}
/**
* Process the blog entries
*
* @param httpServletRequest Request
* @param httpServletResponse Response
* @param user {@link org.blojsom.blog.BlogUser} instance
* @param context Context
* @param entries Blog entries retrieved for the particular request
* @return Modified set of blog entries
* @throws org.blojsom.plugin.BlojsomPluginException
* If there is an error processing the blog entries
*/
public BlogEntry[] process(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlogUser user, Map context, BlogEntry[] entries) throws BlojsomPluginException {
return entries;
}
/**
* Perform any cleanup for the plugin. Called after {@link #process}.
*
* @throws org.blojsom.plugin.BlojsomPluginException
* If there is an error performing cleanup for this plugin
*/
public void cleanup() throws BlojsomPluginException {
}
/**
* Called when BlojsomServlet is taken out of service
*
* @throws org.blojsom.plugin.BlojsomPluginException
* If there is an error in finalizing this plugin
*/
public void destroy() throws BlojsomPluginException {
}
/**
* Handle an event broadcast from another component
*
* @param event {@link org.blojsom.event.BlojsomEvent} to be handled
*/
public void handleEvent(BlojsomEvent event) {
if (event instanceof AddBlogEntryEvent || event instanceof UpdatedBlogEntryEvent) {
BlogEntryEvent blogEntryEvent = (BlogEntryEvent) event;
String text = blogEntryEvent.getBlogEntry().getDescription();
if (!BlojsomUtils.checkNullOrBlank(text) && BlojsomUtils.checkMapForKey(blogEntryEvent.getBlogEntry().getMetaData(), PINGBACK_PLUGIN_METADATA_SEND_PINGBACKS)) {
String pingbackURL = null;
String sourceURI = blogEntryEvent.getBlogEntry().getLink();
String targetURI = null;
Pattern hrefPattern = Pattern.compile(HREF_REGEX, Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.UNICODE_CASE | Pattern.DOTALL);
Matcher hrefMatcher = hrefPattern.matcher(text);
_logger.debug("Checking for href's in entry: " + blogEntryEvent.getBlogEntry().getPermalink());
while (hrefMatcher.find()) {
targetURI = hrefMatcher.group(1);
_logger.debug("Found potential targetURI: " + targetURI);
// Perform an HTTP request and first see if the X-Pingback header is available
try {
HttpURLConnection urlConnection = (HttpURLConnection) new URL(targetURI).openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
pingbackURL = urlConnection.getHeaderField(X_PINGBACK_HEADER);
// If the header is not available, look for the link in the URL content
if (pingbackURL == null) {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), UTF8));
StringBuffer content = new StringBuffer();
String input;
while ((input = bufferedReader.readLine()) != null) {
content.append(input).append(LINE_SEPARATOR);
}
bufferedReader.close();
Pattern pingbackLinkPattern = Pattern.compile(PINGBACK_LINK_REGEX, Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.UNICODE_CASE | Pattern.DOTALL);
Matcher pingbackLinkMatcher = pingbackLinkPattern.matcher(content.toString());
if (pingbackLinkMatcher.find()) {
pingbackURL = pingbackLinkMatcher.group(1);
}
}
// Finally, send the pingback
if (pingbackURL != null && targetURI != null) {
Vector parameters = new Vector();
parameters.add(sourceURI);
parameters.add(targetURI);
try {
_logger.debug("Sending pingback to: " + pingbackURL + " sourceURI: " + sourceURI + " targetURI: " + targetURI);
XmlRpcClient xmlRpcClient = new XmlRpcClient(pingbackURL);
xmlRpcClient.executeAsync(PINGBACK_METHOD, parameters, _callbackHandler);
} catch (MalformedURLException e) {
_logger.error(e);
}
}
} catch (IOException e) {
_logger.error(e);
}
}
} else {
_logger.debug("No text in blog entry or " + PINGBACK_PLUGIN_METADATA_SEND_PINGBACKS + " not enabled.");
}
}
}
/**
* Process an event from another component
*
* @param event {@link BlojsomEvent} to be handled
* @since blojsom 2.24
*/
public void processEvent(BlojsomEvent event) {
}
/**
* Asynchronous callback handler for the pingback ping
*/
private class PingbackPluginAsyncCallback implements AsyncCallback {
/**
* Default constructor
*/
public PingbackPluginAsyncCallback() {
}
/**
* Call went ok, handle result.
*
* @param o Return object
* @param url URL
* @param s String
*/
public void handleResult(Object o, URL url, String s) {
_logger.debug(o.toString());
}
/**
* Something went wrong, handle error.
*
* @param e Exception containing error from XML-RPC call
* @param url URL
* @param s String
*/
public void handleError(Exception e, URL url, String s) {
_logger.error(e);
}
}
}