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1
17 package org.apache.servicemix.components.rss;
18
19 import com.sun.syndication.feed.synd.SyndContent;
20 import com.sun.syndication.feed.synd.SyndContentImpl;
21 import com.sun.syndication.feed.synd.SyndEntry;
22 import com.sun.syndication.feed.synd.SyndEntryImpl;
23 import com.sun.syndication.feed.synd.SyndFeed;
24 import com.sun.syndication.feed.synd.SyndFeedImpl;
25 import com.sun.syndication.io.FeedException;
26 import com.sun.syndication.io.SyndFeedInput;
27 import com.sun.syndication.io.SyndFeedOutput;
28 import com.sun.syndication.io.XmlReader;
29
30 import org.apache.servicemix.components.util.OutBinding;
31 import org.apache.servicemix.expression.Expression;
32 import org.apache.servicemix.expression.ExpressionHelper;
33 import org.apache.servicemix.jbi.jaxp.SourceTransformer;
34
35 import javax.jbi.JBIException;
36 import javax.jbi.messaging.MessageExchange;
37 import javax.jbi.messaging.MessagingException;
38 import javax.jbi.messaging.NormalizedMessage;
39 import javax.xml.transform.Source  ;
40 import javax.xml.transform.TransformerException ;
41
42 import java.io.File ;
43 import java.io.FileWriter ;
44 import java.io.IOException ;
45 import java.io.Writer ;
46 import java.util.ArrayList ;
47 import java.util.Date ;
48 import java.util.List ;
49
50
55 public class FeedWriter extends OutBinding {
56
57 private String feedType = "atom_0.3";
58 private SyndFeed cachedFeed;
59 private String title;
60 private String link = "http://servicemix.org/RSS";
61 private Expression entryTitle;
62 private Expression entryValue;
63 private String feedDescription = "This feed is auto-generated by ServiceMix";
64 private int maximumEntryCount = 200;
65 private File feedFile;
66 private String contentType = "text/plain";
67 private SourceTransformer sourceTransformer = new SourceTransformer();
68 private boolean loadOnStartup = true;
69
70 public SyndFeed getCachedFeed() throws IllegalArgumentException , FeedException, IOException {
71 if (cachedFeed == null) {
72 cachedFeed = loadOrCreateFeed();
73 }
74 return cachedFeed;
75 }
76
77 public void setCachedFeed(SyndFeed feed) {
78 this.cachedFeed = feed;
79 }
80
81 public String getFeedType() {
82 return feedType;
83 }
84
85 public void setFeedType(String feedType) {
86 this.feedType = feedType;
87 }
88
89 public String getFeedDescription() {
90 return feedDescription;
91 }
92
93 public void setFeedDescription(String feedDescription) {
94 this.feedDescription = feedDescription;
95 }
96
97 public String getTitle() {
98 if (title == null) {
99 title = "ServiceMix feed for service: " + getService();
100 }
101 return title;
102 }
103
104 public void setTitle(String title) {
105 this.title = title;
106 }
107
108 public String getLink() {
109 return link;
110 }
111
112 public void setLink(String link) {
113 this.link = link;
114 }
115
116 public Expression getEntryTitle() {
117 return entryTitle;
118 }
119
120 public void setEntryTitle(Expression title) {
121 this.entryTitle = title;
122 }
123
124 public Expression getEntryValue() {
125 return entryValue;
126 }
127
128 public void setEntryValue(Expression entryValue) {
129 this.entryValue = entryValue;
130 }
131
132 public int getMaximumEntryCount() {
133 return maximumEntryCount;
134 }
135
136 public void setMaximumEntryCount(int maximumEntryCount) {
137 this.maximumEntryCount = maximumEntryCount;
138 }
139
140 public File getFeedFile() {
141 if (feedFile == null) {
142 throw new IllegalArgumentException ("You must set the 'feedFile' property");
143 }
144 return feedFile;
145 }
146
147 public void setFeedFile(File feedFile) {
148 this.feedFile = feedFile;
149 }
150
151 public String getContentType() {
152 return contentType;
153 }
154
155 public void setContentType(String contentType) {
156 this.contentType = contentType;
157 }
158
159 public SourceTransformer getSourceTransformer() {
160 return sourceTransformer;
161 }
162
163 public void setSourceTransformer(SourceTransformer sourceTransformer) {
164 this.sourceTransformer = sourceTransformer;
165 }
166
167 public boolean isLoadOnStartup() {
168 return loadOnStartup;
169 }
170
171 public void setLoadOnStartup(boolean loadOnStartup) {
172 this.loadOnStartup = loadOnStartup;
173 }
174
175
178 protected void init() throws JBIException {
179 super.init();
180
181 File file = getFeedFile();
183 if (file.exists() && file.isDirectory()) {
184 throw new IllegalArgumentException ("Cannot generate the cachedFeed as the cachedFeed file is a directory: " + file);
185 }
186 }
187
188 protected void process(MessageExchange exchange, NormalizedMessage message) throws Exception {
189 SyndFeed feed = getCachedFeed();
190 addMessageToFeed(feed, exchange, message);
191 removeExpiredEntries(feed);
192 writeFeed(feed, exchange, message);
193 done(exchange);
194 }
195
196 protected void addMessageToFeed(SyndFeed feed, MessageExchange exchange, NormalizedMessage message) throws TransformerException , MessagingException {
197 List entries = feed.getEntries();
198 SyndEntry entry = createEntry(exchange, message);
199 SyndContent description = createEntryContent(exchange, message);
200 entry.setDescription(description);
201
202
205 List temp = new ArrayList ();
206 temp.add(entry);
207 temp.addAll(entries);
208 feed.setEntries(temp);
209 }
210
211 protected SyndEntry createEntry(MessageExchange exchange, NormalizedMessage message) throws MessagingException {
212 SyndEntry entry = new SyndEntryImpl();
213
214 entry.setTitle(ExpressionHelper.asString(getEntryTitle(), exchange, message, "ServiceMix Feed"));
215 entry.setLink(getLink());
216 entry.setPublishedDate(new Date ());
217 return entry;
218 }
219
220 protected SyndContent createEntryContent(MessageExchange exchange, NormalizedMessage message) throws TransformerException , MessagingException {
221 SyndContent description = new SyndContentImpl();
222 description.setType(contentType);
223 Source content = message.getContent();
224
225 String value = ExpressionHelper.asString(getEntryValue(), exchange, message, null);
226 if (value == null && content != null) {
227 value = getSourceTransformer().toString(content);
228 value = encodeContent(value);
229 }
230 if (value != null) {
231 description.setValue(value);
232 }
233 return description;
234 }
235
236
239 protected String encodeContent(String value) {
240 return "<![CDATA[" + value + "]]>";
241 }
242
243 protected void writeFeed(SyndFeed feed, MessageExchange messageExchange, NormalizedMessage message) throws IOException , FeedException {
244 Writer writer = new FileWriter (feedFile);
245 SyndFeedOutput output = new SyndFeedOutput();
246 output.output(feed, writer);
247 writer.close();
248 }
249
250
255 protected void removeExpiredEntries(SyndFeed feed) {
256 if (maximumEntryCount > 0) {
258 List entries = feed.getEntries();
259 int size = entries.size();
260 if (size > maximumEntryCount) {
261 entries.subList(maximumEntryCount, size).clear();
262 }
263 }
264 }
265
266 protected SyndFeed loadOrCreateFeed() throws IllegalArgumentException , FeedException, IOException {
267 if (isLoadOnStartup()) {
268 File file = getFeedFile();
269 if (file.exists() && file.isFile()) {
270 SyndFeedInput input = new SyndFeedInput();
271 XmlReader xmlReader = new XmlReader(file);
272 return input.build(xmlReader);
273 }
274 }
275 return createFeed();
276 }
277
278 protected SyndFeed createFeed() {
279 SyndFeed feed = new SyndFeedImpl();
280 feed.setFeedType(feedType);
281
282 feed.setTitle(getTitle());
283 feed.setLink(getLink());
284 feed.setDescription(getFeedDescription());
285 return feed;
286 }
287
288 }
289 |
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