/* (non-Javadoc)
* @see uk.ac.jorum.packager.detector.BasePackageDetector#isValidPackage()
*/
@Override
public boolean isValidPackage() {
boolean result = false;
boolean isUrl = false;
try {
// Download the feed
// url is the bitstream contents
// Check that the bitstream belongs in the FEED_BUNDLE - if it isn't then we may be looking at
// raw content ie not a link to a feed!
Bundle[] bundles = this.getBitstream().getBundles();
for (Bundle b : bundles) {
if (b.getName().equals(Constants.FEED_BUNDLE)) {
isUrl = true;
break;
}
}
if (isUrl) {
Document xmlDoc = getRssDocument(this.getBitstream());
Element root = xmlDoc.getRootElement();
Attribute version = root.getAttribute("version");
if (root.getName().equals("rss") && version != null && version.getValue().equals("2.0")) {
result = true;
}
}
} catch (Exception e) {
ExceptionLogger.logException(log, e);
}
return result;
}
public static Document getRssDocument(Bitstream rssUrlBitstream) {
try {
return getRssDocument(
rssUrlBitstream.getbContext(),
rssUrlBitstream.retrieve(),
rssUrlBitstream.getBundles()[0]);
} catch (Exception e) {
ExceptionLogger.logException(log, e);
}
return null;
}
public static Document getRssDocument(Context context, InputStream is, Bundle feedBundle) {
GetMethod method = null;
BufferedReader in = null;
try {
// Download the feed
// url is the bitstream contents
in = new BufferedReader(new InputStreamReader(is));
String url = in.readLine();
// need to replace the feed prefix with the HTTP protocol ie replace feed:// with http://
url = url.replaceAll(PackageDetectorStep.FEED_PREFIX, "http://");
HttpClient client = new HttpClient();
// Create a method instance.
method = new GetMethod(url);
// Provide custom retry handler is necessary
method
.getParams()
.setParameter(
HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler(3, false));
// Execute the method.
int statusCode = client.executeMethod(method);
if (statusCode != HttpStatus.SC_OK) {
throw new Exception("Method failed: " + method.getStatusLine());
}
// Read the response body.
byte[] responseBody = method.getResponseBody();
// Store the response in a bitstream so that the ingester can use it later
if (feedBundle != null) {
BitstreamFormat bs_format = BitstreamFormat.findByShortDescription(context, "Text");
BundleUtils.setBitstreamFromBytes(
feedBundle, Constants.FEED_BUNDLE_CONTENTS_NAME, bs_format, responseBody, false);
}
// Now see if we have a RSS v2.0 document
SAXBuilder builder = new SAXBuilder(false);
Document xmlDoc = builder.build(new ByteArrayInputStream(responseBody));
// XMLOutputter outputPretty = new XMLOutputter(Format.getPrettyFormat());
// log.debug("Got RSS DOCUMENT:");
// log.debug(outputPretty.outputString(xmlDoc));
return xmlDoc;
} catch (Exception e) {
ExceptionLogger.logException(log, e);
} finally {
// Release the connection.
method.releaseConnection();
try {
in.close();
} catch (Exception e) {
}
}
return null;
}
