/*
* $Header: /home/cvs/jakarta-struts/src/tiles-documentation/org/apache/struts/webapp/tiles/rssChannel/Channels.java,v 1.11 2004/03/14 06:23:53 sraeburn Exp $
* $Revision: 1.11 $
* $Date: 2004/03/14 06:23:53 $
*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.struts.webapp.tiles.rssChannel;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.digester.rss.Channel;
import org.apache.commons.digester.rss.RSSDigester;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.tiles.ComponentContext;
/**
* Read and parse RSS files found at on a given
* list in user request or session, save the Channel
* beans in request scope,and forward to "continue".
* @expects path={uri} on command line or as parameter property to ActionMapping.
* @expects an input page or error forwarding if exception digesting RSS
* @version $Revision: 1.11 $ $Date: 2004/03/14 06:23:53 $
*/
public final class Channels extends Action {
/**
* Commons Logging instance.
*/
private static Log log = LogFactory.getLog(Channels.class);
/**
* Tile attribute key for saving Channel bean
*/
public static final String CHANNELS_KEY = "CHANNELS";
/**
* Tile attribute key for getting Channel urls list
*/
public static final String CHANNEL_URLS_KEY = "urls";
/**
* Tile attribute key for getting Channel url attribute
*/
public static final String CHANNEL_URL_KEY = "url";
/**
* Main process of class. Reads, parses
*/
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception {
log.debug("Enter Rss Channel Action");
// Try to retrieve tile context
ComponentContext context = ComponentContext.getContext(request);
if (context == null) {
throw new ServletException("This action must be called by a Tile, not directly");
}
ActionMessages errors = new ActionMessages();
// -- Retrieve parameters --
// Urls can come from a list, or from a single attribute.
List channels = (List) context.getAttribute(CHANNEL_URLS_KEY);
if (channels == null) {
Object url = context.getAttribute(CHANNEL_URL_KEY);
channels = new ArrayList(1);
channels.add(url);
}
log.debug("urls count" + channels.size());
// -- Loop through channels --
ArrayList channelBeans = new ArrayList(channels.size());
try {
for (int i = 0; i < channels.size(); i++) {
RSSDigester digester = new RSSDigester();
String url = (String) channels.get(i);
// Add application path if needed
if (url.startsWith("/")) {
url = toFullUrl(request, url);
}
log.debug("Channel url=" + url);
Channel obj = (Channel) digester.parse(url);
log.debug("Channel:" + obj);
channelBeans.add(obj);
}
} catch (Throwable t) {
errors.add(
ActionMessages.GLOBAL_MESSAGE,
new ActionMessage("rss.access.error"));
servlet.log(t.toString());
}
// -- Handle Errors ---
if (!errors.isEmpty()) {
this.saveErrors(request, errors);
if (mapping.getInput() != null) {
return new ActionForward(mapping.getInput());
}
// If no input page, use error forwarding
log.debug("Exit Rss Channel Action : error");
return mapping.findForward("error");
}
// -- Save Bean, and Continue ---
log.debug("Exit Rss Channel Action");
// Use Tile context to pass channels
context.putAttribute(CHANNELS_KEY, channelBeans);
return mapping.findForward("continue");
}
private String toFullUrl(HttpServletRequest request, String url) {
StringBuffer buff = new StringBuffer();
buff.append(request.getScheme()).append("://").append(
request.getServerName());
if (request.getServerPort() != 80) {
buff.append(":").append(request.getServerPort());
}
buff.append(request.getContextPath()).append(url);
return buff.toString();
}
}