001/* 002 * Copyright 2002-2014 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.servlet.view.feed; 018 019import java.util.List; 020import java.util.Map; 021import javax.servlet.http.HttpServletRequest; 022import javax.servlet.http.HttpServletResponse; 023 024import com.rometools.rome.feed.atom.Entry; 025import com.rometools.rome.feed.atom.Feed; 026 027/** 028 * Abstract superclass for Atom Feed views, using the 029 * <a href="https://github.com/rometools/rome">ROME</a> package. 030 * 031 * <p>><b>NOTE: As of Spring 4.1, this is based on the {@code com.rometools} 032 * variant of ROME, version 1.5. Please upgrade your build dependency.</b> 033 * 034 * <p>Application-specific view classes will extend this class. 035 * The view will be held in the subclass itself, not in a template. 036 * Main entry points are the {@link #buildFeedMetadata} and {@link #buildFeedEntries}. 037 * 038 * <p>Thanks to Jettro Coenradie and Sergio Bossa for the original feed view prototype! 039 * 040 * @author Arjen Poutsma 041 * @author Juergen Hoeller 042 * @since 3.0 043 * @see #buildFeedMetadata 044 * @see #buildFeedEntries 045 * @see <a href="https://www.atomenabled.org/developers/syndication/">Atom Syndication Format</a> 046 */ 047public abstract class AbstractAtomFeedView extends AbstractFeedView<Feed> { 048 049 public static final String DEFAULT_FEED_TYPE = "atom_1.0"; 050 051 private String feedType = DEFAULT_FEED_TYPE; 052 053 054 public AbstractAtomFeedView() { 055 setContentType("application/atom+xml"); 056 } 057 058 /** 059 * Set the Rome feed type to use. 060 * <p>Defaults to Atom 1.0. 061 * @see Feed#setFeedType(String) 062 * @see #DEFAULT_FEED_TYPE 063 */ 064 public void setFeedType(String feedType) { 065 this.feedType = feedType; 066 } 067 068 /** 069 * Create a new Feed instance to hold the entries. 070 * <p>By default returns an Atom 1.0 feed, but the subclass can specify any Feed. 071 * @see #setFeedType(String) 072 */ 073 @Override 074 protected Feed newFeed() { 075 return new Feed(this.feedType); 076 } 077 078 /** 079 * Invokes {@link #buildFeedEntries(Map, HttpServletRequest, HttpServletResponse)} 080 * to get a list of feed entries. 081 */ 082 @Override 083 protected final void buildFeedEntries(Map<String, Object> model, Feed feed, 084 HttpServletRequest request, HttpServletResponse response) throws Exception { 085 086 List<Entry> entries = buildFeedEntries(model, request, response); 087 feed.setEntries(entries); 088 } 089 090 /** 091 * Subclasses must implement this method to build feed entries, given the model. 092 * <p>Note that the passed-in HTTP response is just supposed to be used for 093 * setting cookies or other HTTP headers. The built feed itself will automatically 094 * get written to the response after this method returns. 095 * @param model the model Map 096 * @param request in case we need locale etc. Shouldn't look at attributes. 097 * @param response in case we need to set cookies. Shouldn't write to it. 098 * @return the feed entries to be added to the feed 099 * @throws Exception any exception that occurred during document building 100 * @see Entry 101 */ 102 protected abstract List<Entry> buildFeedEntries( 103 Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) 104 throws Exception; 105 106}