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1
26
27
29 package de.nava.informa.parsers;
30
31 import java.io.File  ;
32 import java.io.IOException ;
33 import java.io.InputStream ;
34 import java.io.Reader ;
35 import java.net.URL ;
36 import java.util.Iterator ;
37
38 import org.apache.commons.logging.Log;
39 import org.apache.commons.logging.LogFactory;
40 import org.jdom.Document;
41 import org.jdom.Element;
42 import org.jdom.JDOMException;
43 import org.jdom.input.SAXBuilder;
44 import org.xml.sax.InputSource ;
45
46 import de.nava.informa.core.ChannelBuilderIF;
47 import de.nava.informa.core.ItemIF;
48 import de.nava.informa.core.ChannelIF;
49 import de.nava.informa.core.ParseException;
50 import de.nava.informa.core.UnsupportedFormatException;
51
53
62 public class FeedParser {
63
64 private static Log logger = LogFactory.getLog(FeedParser.class);
65
66 public static ChannelIF parse(ChannelBuilderIF cBuilder, URL aURL)
67 throws IOException , ParseException {
68 return parse(cBuilder, new InputSource (aURL.toExternalForm()), aURL);
69 }
70
71 public static ChannelIF parse(ChannelBuilderIF cBuilder, String url)
72 throws IOException , ParseException {
73 URL aURL = null;
74 try {
75 aURL = new URL (url);
76 } catch (java.net.MalformedURLException e) {
77 logger.warn("Could not create URL for " + url);
78 }
79 return parse(cBuilder, new InputSource (url), aURL);
80 }
81
82 public static ChannelIF parse(ChannelBuilderIF cBuilder, Reader reader)
83 throws IOException , ParseException {
84 return parse(cBuilder, new InputSource (reader), null);
85 }
86
87 public static ChannelIF parse(ChannelBuilderIF cBuilder, InputStream stream)
88 throws IOException , ParseException {
89 return parse(cBuilder, new InputSource (stream), null);
90 }
91
92 public static ChannelIF parse(ChannelBuilderIF cBuilder, File aFile)
93 throws IOException , ParseException {
94 URL aURL = null;
95 try {
96 aURL = aFile.toURL();
97 } catch (java.net.MalformedURLException e) {
98 throw new IOException ("File " + aFile + " had invalid URL " +
99 "representation.");
100 }
101 return parse(cBuilder, new InputSource (aURL.toExternalForm()), aURL);
102 }
103
104 public static ChannelIF parse(ChannelBuilderIF cBuilder,
105 InputSource inpSource,
106 URL baseLocation)
107 throws IOException , ParseException {
108 SAXBuilder saxBuilder = new SAXBuilder(false);
110 try {
113 Document doc = saxBuilder.build(inpSource);
114 ChannelIF channel = parse(cBuilder, doc);
115 channel.setLocation(baseLocation);
116 return channel;
117 } catch (JDOMException e) {
118 throw new ParseException(e);
119 }
120 }
121
122
126 private static synchronized ChannelIF parse(ChannelBuilderIF cBuilder,
127 Document doc)
128 throws ParseException {
129
130 if (cBuilder == null) {
131 throw new RuntimeException ("Without builder no channel can " +
132 "be created.");
133 }
134 logger.debug("start parsing.");
135 Element root = doc.getRootElement();
137 String rootElement = root.getName().toLowerCase();
138 if (rootElement.startsWith("rss")) {
140 String rssVersion = root.getAttribute("version").getValue();
141 if (rssVersion.indexOf("0.91") >= 0) {
142 logger.info("Channel uses RSS root element (Version 0.91).");
143 return RSS_0_91_Parser.parse(cBuilder, root);
144 } else if (rssVersion.indexOf("0.92") >= 0) {
145 logger.info("Channel uses RSS root element (Version 0.92).");
146 return RSS_0_91_Parser.parse(cBuilder, root);
149 } else if (rootElement.indexOf("0.93") >= 0) {
150 logger.info("Channel uses RSS root element (Version 0.93).");
151 logger.warn("RSS 0.93 not fully supported yet, fall back to 0.91.");
152 } else if (rootElement.indexOf("0.94") >= 0) {
154 logger.info("Channel uses RSS root element (Version 0.94).");
155 logger.warn("RSS 0.94 not fully supported yet, will use RSS 2.0");
156 return RSS_2_0_Parser.parse(cBuilder, root);
158 } else if (rssVersion.indexOf("2.0") >= 0 || rssVersion.equals("2")) {
159 logger.info("Channel uses RSS root element (Version 2.0).");
160 return RSS_2_0_Parser.parse(cBuilder, root);
161 } else {
162 throw new UnsupportedFormatException("Unsupported RSS version [" +
163 rssVersion + "].");
164 }
165 } else if (rootElement.indexOf("rdf") >= 0) {
166 return RSS_1_0_Parser.parse(cBuilder, root);
167 } else if (rootElement.indexOf("feed") >= 0) {
168 String feedVersion = root.getAttribute("version").getValue();
169 if (feedVersion.indexOf("0.1") >= 0 || feedVersion.indexOf("0.2") >= 0) {
170 logger.info("Channel uses feed root element (Version " + feedVersion + ").");
171 logger.warn("This atom version is not really supported yet, assume Atom 0.3 format");
172 return Atom_0_3_Parser.parse(cBuilder, root);
173 } else if (feedVersion.indexOf("0.3") >= 0) {
174 logger.info("Channel uses feed root element (Version 0.3).");
175 return Atom_0_3_Parser.parse(cBuilder, root);
176 } else {
177 throw new UnsupportedFormatException("Unsupported feed version [" +
178 feedVersion + "].");
179 }
180 }
181
182 throw new UnsupportedFormatException("Unsupported root element [" +
184 rootElement + "].");
185 }
186
187
188
190 public static void main(String args[]) throws IOException , ParseException {
191
192 if (args.length < 2) {
193 System.err.println("Usage: java " + FeedParser.class.getName() +
194 " [-f <filename> | -u <url>]");
195 System.exit(1);
196 }
197
198 String option = args[0];
199 String data = args[1];
200
201 ChannelIF channel = null;
202
203 ChannelBuilderIF builder = new de.nava.informa.impl.basic.ChannelBuilder();
204 if (option.trim().startsWith("-f")) {
205 channel = FeedParser.parse(builder, new File (data));
206 } else {
207 channel = FeedParser.parse(builder, new URL (data));
208 }
209
210 System.out.println("Channel format: " + channel.getFormat().toString());
211 System.out.println(channel);
212 System.out.println("containing " + channel.getItems().size() + " items");
213 Iterator items = channel.getItems().iterator();
214 while (items.hasNext()) {
215 ItemIF item = (ItemIF) items.next();
216 System.out.println(" - " + item);
217 }
218 }
219 }
220 |
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