/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. The ASF licenses this file to You
* 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. For additional information regarding
* copyright in this work, please see the NOTICE file in the top level
* directory of this distribution.
*/
package org.apache.roller.ui.rendering.servlets;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.roller.RollerException;
import org.apache.roller.business.RollerFactory;
import org.apache.roller.business.WeblogManager;
import org.apache.roller.config.RollerConfig;
import org.apache.roller.config.RollerRuntimeConfig;
import org.apache.roller.pojos.StaticTemplate;
import org.apache.roller.pojos.Template;
import org.apache.roller.pojos.WebsiteData;
import org.apache.roller.ui.rendering.util.WeblogFeedRequest;
import org.apache.roller.util.cache.CachedContent;
import org.apache.roller.ui.rendering.Renderer;
import org.apache.roller.ui.rendering.RendererManager;
import org.apache.roller.ui.rendering.model.ModelLoader;
import org.apache.roller.ui.rendering.util.cache.SiteWideCache;
import org.apache.roller.ui.rendering.util.cache.WeblogFeedCache;
import org.apache.roller.ui.rendering.util.ModDateHeaderUtil;
/**
* Responsible for rendering weblog feeds.
*
* @web.servlet name="FeedServlet" load-on-startup="5"
* @web.servlet-mapping url-pattern="/roller-ui/rendering/feed/*"
*/
public class FeedServlet extends HttpServlet {
private static Log log = LogFactory.getLog(FeedServlet.class);
private WeblogFeedCache weblogFeedCache = null;
private SiteWideCache siteWideCache = null;
/**
* Init method for this servlet
*/
public void init(ServletConfig servletConfig) throws ServletException {
super.init(servletConfig);
log.info("Initializing FeedServlet");
// get a reference to the weblog feed cache
this.weblogFeedCache = WeblogFeedCache.getInstance();
// get a reference to the site wide cache
this.siteWideCache = SiteWideCache.getInstance();
}
/**
* Handle GET requests for weblog feeds.
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
log.debug("Entering");
WebsiteData weblog = null;
boolean isSiteWide = false;
WeblogFeedRequest feedRequest = null;
try {
// parse the incoming request and extract the relevant data
feedRequest = new WeblogFeedRequest(request);
weblog = feedRequest.getWeblog();
if(weblog == null) {
throw new RollerException("unable to lookup weblog: "+
feedRequest.getWeblogHandle());
}
// is this the site-wide weblog?
isSiteWide = RollerRuntimeConfig.isSiteWideWeblog(feedRequest.getWeblogHandle());
} catch(Exception e) {
// invalid feed request format or weblog doesn't exist
log.debug("error creating weblog feed request", e);
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
// determine the lastModified date for this content
long lastModified = System.currentTimeMillis();
if(isSiteWide) {
lastModified = siteWideCache.getLastModified().getTime();
} else if (weblog.getLastModified() != null) {
lastModified = weblog.getLastModified().getTime();
}
// Respond with 304 Not Modified if it is not modified.
if (ModDateHeaderUtil.respondIfNotModified(request,response,lastModified)) {
return;
}
// set last-modified date
ModDateHeaderUtil.setLastModifiedHeader(response, lastModified);
// set content type
String accepts = request.getHeader("Accept");
String userAgent = request.getHeader("User-Agent");
if (RollerRuntimeConfig.getBooleanProperty("site.newsfeeds.styledFeeds") &&
accepts != null && accepts.indexOf("*/*") != -1 &&
userAgent != null && userAgent.startsWith("Mozilla")) {
// client is a browser and feed style is enabled so we want
// browsers to load the page rather than popping up the download
// dialog, so we provide a content-type that browsers will display
response.setContentType("text/xml");
} else if("rss".equals(feedRequest.getFormat())) {
response.setContentType("application/rss+xml; charset=utf-8");
} else if("atom".equals(feedRequest.getFormat())) {
response.setContentType("application/atom+xml; charset=utf-8");
}
// generate cache key
String cacheKey = null;
if(isSiteWide) {
cacheKey = siteWideCache.generateKey(feedRequest);
} else {
cacheKey = weblogFeedCache.generateKey(feedRequest);
}
// cached content checking
CachedContent cachedContent = null;
if(isSiteWide) {
cachedContent = (CachedContent) siteWideCache.get(cacheKey);
} else {
cachedContent = (CachedContent) weblogFeedCache.get(cacheKey, lastModified);
}
if(cachedContent != null) {
log.debug("HIT "+cacheKey);
response.setContentLength(cachedContent.getContent().length);
response.getOutputStream().write(cachedContent.getContent());
return;
} else {
log.debug("MISS "+cacheKey);
}
// validation. make sure that request input makes sense.
boolean invalid = false;
if(feedRequest.getLocale() != null) {
// locale view only allowed if weblog has enabled it
if(!feedRequest.getWeblog().isEnableMultiLang()) {
invalid = true;
}
}
if(feedRequest.getWeblogCategoryName() != null) {
// category specified. category must exist.
if(feedRequest.getWeblogCategory() == null) {
invalid = true;
}
} else if(feedRequest.getTags() != null && feedRequest.getTags().size() > 0) {
try {
// tags specified. make sure they exist.
WeblogManager wmgr = RollerFactory.getRoller().getWeblogManager();
invalid = !wmgr.getTagComboExists(feedRequest.getTags(), (isSiteWide) ? null : weblog);
} catch (RollerException ex) {
invalid = true;
}
}
if(invalid) {
if(!response.isCommitted()) response.reset();
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
// looks like we need to render content
HashMap model = new HashMap();
String pageId = null;
try {
// determine what template to render with
if (RollerRuntimeConfig.isSiteWideWeblog(weblog.getHandle())) {
pageId = "templates/feeds/site-"+feedRequest.getType()+"-"+feedRequest.getFormat()+".vm";
} else {
pageId = "templates/feeds/weblog-"+feedRequest.getType()+"-"+feedRequest.getFormat()+".vm";
}
// populate the rendering model
Map initData = new HashMap();
initData.put("request", request);
initData.put("weblogRequest", feedRequest);
// Load models for feeds
String feedModels = RollerConfig.getProperty("rendering.feedModels");
ModelLoader.loadModels(feedModels, model, initData, true);
// Load special models for site-wide blog
if(RollerRuntimeConfig.isSiteWideWeblog(weblog.getHandle())) {
String siteModels = RollerConfig.getProperty("rendering.siteModels");
ModelLoader.loadModels(siteModels, model, initData, true);
}
// Load weblog custom models
ModelLoader.loadCustomModels(weblog, model, initData);
} catch (RollerException ex) {
log.error("ERROR loading model for page", ex);
if(!response.isCommitted()) response.reset();
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
return;
}
// lookup Renderer we are going to use
Renderer renderer = null;
try {
log.debug("Looking up renderer");
Template template = new StaticTemplate(pageId, null, "velocity");
renderer = RendererManager.getRenderer(template);
} catch(Exception e) {
// nobody wants to render my content :(
// TODO: this log message has been disabled because it fills up
// the logs with useless errors due to the fact that the way these
// template ids are formed comes directly from the request and it
// often gets bunk data causing invalid template ids.
// at some point we should have better validation on the input so
// that we can quickly dispatch invalid feed requests and only
// get this far if we expect the template to be found
//log.error("Couldn't find renderer for page "+pageId, e);
if(!response.isCommitted()) response.reset();
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
// render content. use default size of about 24K for a standard page
CachedContent rendererOutput = new CachedContent(24567);
try {
log.debug("Doing rendering");
renderer.render(model, rendererOutput.getCachedWriter());
// flush rendered output and close
rendererOutput.flush();
rendererOutput.close();
} catch(Exception e) {
// bummer, error during rendering
log.error("Error during rendering for page "+pageId, e);
if(!response.isCommitted()) response.reset();
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
// post rendering process
// flush rendered content to response
log.debug("Flushing response output");
response.setContentLength(rendererOutput.getContent().length);
response.getOutputStream().write(rendererOutput.getContent());
// cache rendered content. only cache if user is not logged in?
log.debug("PUT "+cacheKey);
if(isSiteWide) {
siteWideCache.put(cacheKey, rendererOutput);
} else {
weblogFeedCache.put(cacheKey, rendererOutput);
}
log.debug("Exiting");
}
}