/*
* Copyright 2002-2014 the original author or authors.
*
* 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.springframework.web.servlet.view.feed;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.rometools.rome.feed.atom.Entry;
import com.rometools.rome.feed.atom.Feed;
/**
* Abstract superclass for Atom Feed views, using the
* <a href="https://github.com/rometools/rome">ROME</a> package.
*
* <p>><b>NOTE: As of Spring 4.1, this is based on the {@code com.rometools}
* variant of ROME, version 1.5. Please upgrade your build dependency.</b>
*
* <p>Application-specific view classes will extend this class.
* The view will be held in the subclass itself, not in a template.
* Main entry points are the {@link #buildFeedMetadata} and {@link #buildFeedEntries}.
*
* <p>Thanks to Jettro Coenradie and Sergio Bossa for the original feed view prototype!
*
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.0
* @see #buildFeedMetadata
* @see #buildFeedEntries
* @see <a href="http://www.atomenabled.org/developers/syndication/">Atom Syndication Format</a>
*/
public abstract class AbstractAtomFeedView extends AbstractFeedView<Feed> {
public static final String DEFAULT_FEED_TYPE = "atom_1.0";
private String feedType = DEFAULT_FEED_TYPE;
public AbstractAtomFeedView() {
setContentType("application/atom+xml");
}
/**
* Set the Rome feed type to use.
* <p>Defaults to Atom 1.0.
* @see Feed#setFeedType(String)
* @see #DEFAULT_FEED_TYPE
*/
public void setFeedType(String feedType) {
this.feedType = feedType;
}
/**
* Create a new Feed instance to hold the entries.
* <p>By default returns an Atom 1.0 feed, but the subclass can specify any Feed.
* @see #setFeedType(String)
*/
@Override
protected Feed newFeed() {
return new Feed(this.feedType);
}
/**
* Invokes {@link #buildFeedEntries(Map, HttpServletRequest, HttpServletResponse)}
* to get a list of feed entries.
*/
@Override
protected final void buildFeedEntries(Map<String, Object> model, Feed feed,
HttpServletRequest request, HttpServletResponse response) throws Exception {
List<Entry> entries = buildFeedEntries(model, request, response);
feed.setEntries(entries);
}
/**
* Subclasses must implement this method to build feed entries, given the model.
* <p>Note that the passed-in HTTP response is just supposed to be used for
* setting cookies or other HTTP headers. The built feed itself will automatically
* get written to the response after this method returns.
* @param model the model Map
* @param request in case we need locale etc. Shouldn't look at attributes.
* @param response in case we need to set cookies. Shouldn't write to it.
* @return the feed entries to be added to the feed
* @throws Exception any exception that occurred during document building
* @see Entry
*/
protected abstract List<Entry> buildFeedEntries(
Map<String, Object> model, HttpServletRequest request, HttpServletResponse response)
throws Exception;
}