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1 package org.springframework.samples.tiles;
2
3 import java.net.MalformedURLException  ;
4 import java.net.URL ;
5 import java.util.ArrayList ;
6 import java.util.Iterator ;
7 import java.util.List ;
8
9 import javax.servlet.http.HttpServletRequest ;
10 import javax.servlet.http.HttpServletResponse ;
11
12 import org.apache.struts.tiles.ComponentContext;
13 import org.dom4j.Document;
14 import org.dom4j.DocumentException;
15 import org.dom4j.DocumentFactory;
16 import org.dom4j.Element;
17 import org.dom4j.Node;
18 import org.dom4j.io.SAXReader;
19
20 import org.springframework.web.servlet.view.tiles.ComponentControllerSupport;
21
22
28 public class NewsFeedController extends ComponentControllerSupport {
29
30 protected void doPerform(
31 ComponentContext componentContext, HttpServletRequest request, HttpServletResponse response)
32 throws Exception {
33
34 NewsFeedConfigurer configurer = (NewsFeedConfigurer) getApplicationContext().getBean("feedConfigurer");
35 String uri = configurer.feedUri((String ) componentContext.getAttribute("sourceName"));
36 NewsReader reader = new NewsReader(uri);
37
38 int size = Integer.parseInt((String ) componentContext.getAttribute("size"));
39 List items = new ArrayList ();
40 for (int i = 0; i < size && i < reader.size(); i++) {
41 NewsItem item = new NewsItem();
42 item.setLink(reader.getLinkAt(i));
43 item.setTitle(reader.getTitleAt(i));
44 item.setSourceName((String ) componentContext.getAttribute("sourceName"));
45 items.add(item);
46 }
47
48 componentContext.putAttribute("items", items);
49 }
50
51
52 private static class NewsReader {
53
54 private Document feed;
55
56 private String type;
57
58 public NewsReader(String uriString) throws MalformedURLException , DocumentException {
59 DocumentFactory docFactory = DocumentFactory.getInstance();
61 SAXReader saxReader = new SAXReader(docFactory, false);
62 URL uri = new URL (uriString);
63 this.feed = saxReader.read(uri);
64 this.type = feed.getRootElement().getName();
66 }
67
68 private String getChannelPrefix() {
69 if ("rss".equals(this.type)) {
70 return "/*/*/";
71 }
72 else {
73 return "/*/";
74 }
75 }
76
77 public int size() {
78 if ("RDF".equals(this.type)) {
80 int size = 0;
81 Iterator it = feed.getRootElement().elements().iterator();
82 while (it.hasNext()) {
83 String qName = ((Element) it.next()).getQualifiedName();
84 if (qName.equals("item")) {
85 size++;
86 }
87 }
88 return size;
89 }
90 return this.feed.selectNodes(getChannelPrefix() + "item").size();
91 }
92
93 public String getItemAsXML(int index) {
94 Node node = null;
95
96 if ("RDF".equals(this.type)) {
98 node = getRDFNodeAt(index, null);
99 }
100 else {
101 node = this.feed.selectSingleNode(getChannelPrefix() + "item[" + (index + 1) + "]");
102 }
103
104 if (node != null) {
106 return node.asXML();
107 }
108
109 return null;
110 }
111
112 public String getChannelTitle() {
113 return this.feed.getRootElement().element("channel").element("title").getText();
114 }
115
116 public String getChannelLink() {
117 return this.feed.getRootElement().element("channel").element("link").getText();
118 }
119
120 public String getLinkAt(int i) {
121 return getItemNodeValue(i, "link");
122 }
123
124 public String getTitleAt(int i) {
125 return getItemNodeValue(i, "title");
126 }
127
128 public String getDescriptionAt(int i) {
129 return getItemNodeValue(i, "description");
130 }
131
132 private String getItemNodeValue(int index, String nodeName) {
133 String value = null;
134
135 if ("RDF".equals(this.type)) {
137 value = getRDFNodeAt(index, nodeName).getText();
138 }
139 else {
140 value = this.feed.selectSingleNode(
141 getChannelPrefix() + "item[" + (index + 1) + "]/" + nodeName).getText();
142 }
143
144 return value;
145 }
146
147 private List getRDFItemNodes() {
148 List items = new ArrayList (this.feed.getRootElement().elements().size());
150 Iterator it = this.feed.getRootElement().elements().iterator();
151 while (it.hasNext()) {
152 Element elem = (Element) it.next();
153 String qName = elem.getQualifiedName();
154 if ("item".equals(qName)) {
155 items.add(elem);
157 }
158 }
159 return items;
160 }
161
162 private Node getRDFNodeAt(int i, String subNode) {
163 List items = getRDFItemNodes();
165 Element item = (Element) items.get(i);
167 if (subNode == null) {
168 return item;
169 }
170 else {
171 return item.element(subNode);
172 }
173 }
174 }
175
176 }
177 |
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