001/* 002 * Copyright 2002-2018 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; 021 022import javax.servlet.http.HttpServletRequest; 023import javax.servlet.http.HttpServletResponse; 024 025import com.rometools.rome.feed.atom.Entry; 026import com.rometools.rome.feed.atom.Feed; 027 028/** 029 * Abstract superclass for Atom Feed views, using the 030 * <a href="https://github.com/rometools/rome">ROME</a> package. 031 * 032 * <p>><b>NOTE: As of Spring 4.1, this is based on the {@code com.rometools} 033 * variant of ROME, version 1.5. Please upgrade your build dependency.</b> 034 * 035 * <p>Application-specific view classes will extend this class. 036 * The view will be held in the subclass itself, not in a template. 037 * Main entry points are the {@link #buildFeedMetadata} and {@link #buildFeedEntries}. 038 * 039 * <p>Thanks to Jettro Coenradie and Sergio Bossa for the original feed view prototype! 040 * 041 * @author Arjen Poutsma 042 * @author Juergen Hoeller 043 * @since 3.0 044 * @see #buildFeedMetadata 045 * @see #buildFeedEntries 046 * @see <a href="https://www.atomenabled.org/developers/syndication/">Atom Syndication Format</a> 047 */ 048public abstract class AbstractAtomFeedView extends AbstractFeedView<Feed> { 049 050 /** 051 * The default feed type used. 052 */ 053 public static final String DEFAULT_FEED_TYPE = "atom_1.0"; 054 055 private String feedType = DEFAULT_FEED_TYPE; 056 057 058 public AbstractAtomFeedView() { 059 setContentType("application/atom+xml"); 060 } 061 062 /** 063 * Set the Rome feed type to use. 064 * <p>Defaults to Atom 1.0. 065 * @see Feed#setFeedType(String) 066 * @see #DEFAULT_FEED_TYPE 067 */ 068 public void setFeedType(String feedType) { 069 this.feedType = feedType; 070 } 071 072 /** 073 * Create a new Feed instance to hold the entries. 074 * <p>By default returns an Atom 1.0 feed, but the subclass can specify any Feed. 075 * @see #setFeedType(String) 076 */ 077 @Override 078 protected Feed newFeed() { 079 return new Feed(this.feedType); 080 } 081 082 /** 083 * Invokes {@link #buildFeedEntries(Map, HttpServletRequest, HttpServletResponse)} 084 * to get a list of feed entries. 085 */ 086 @Override 087 protected final void buildFeedEntries(Map<String, Object> model, Feed feed, 088 HttpServletRequest request, HttpServletResponse response) throws Exception { 089 090 List<Entry> entries = buildFeedEntries(model, request, response); 091 feed.setEntries(entries); 092 } 093 094 /** 095 * Subclasses must implement this method to build feed entries, given the model. 096 * <p>Note that the passed-in HTTP response is just supposed to be used for 097 * setting cookies or other HTTP headers. The built feed itself will automatically 098 * get written to the response after this method returns. 099 * @param model the model Map 100 * @param request in case we need locale etc. Shouldn't look at attributes. 101 * @param response in case we need to set cookies. Shouldn't write to it. 102 * @return the feed entries to be added to the feed 103 * @throws Exception any exception that occurred during document building 104 * @see Entry 105 */ 106 protected abstract List<Entry> buildFeedEntries( 107 Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) 108 throws Exception; 109 110}