/**
* Read urn.
*
* @param file the file
* @return The URN specified in the METS file or null if the METS file doesn't specify an URN
* @throws IOException Signals that an I/O exception has occurred.
* @throws ParseException the parse exception
* @author Thomas Kleinke
*/
public String readURN(File file) throws IOException, ParseException {
FileInputStream fileInputStream = new FileInputStream(file);
BOMInputStream bomInputStream = new BOMInputStream(fileInputStream);
XMLReader xmlReader = null;
SAXParserFactory spf = SAXParserFactory.newInstance();
try {
xmlReader = spf.newSAXParser().getXMLReader();
} catch (Exception e) {
fileInputStream.close();
bomInputStream.close();
throw new IOException("Error creating SAX parser", e);
}
xmlReader.setErrorHandler(err);
NodeFactory nodeFactory = new PremisXmlReaderNodeFactory();
Builder parser = new Builder(xmlReader, false, nodeFactory);
logger.trace("Successfully built builder and XML reader");
try {
String urn = null;
Document doc = parser.build(bomInputStream);
Element root = doc.getRootElement();
Element dmdSecEl = root.getFirstChildElement("dmdSec", METS_NS);
if (dmdSecEl == null) return null;
Element mdWrapEl = dmdSecEl.getFirstChildElement("mdWrap", METS_NS);
if (mdWrapEl == null) return null;
Element xmlDataEl = mdWrapEl.getFirstChildElement("xmlData", METS_NS);
if (xmlDataEl == null) return null;
Element modsEl = xmlDataEl.getFirstChildElement("mods", MODS_NS);
if (modsEl == null) return null;
Elements identifierEls = modsEl.getChildElements("identifier", MODS_NS);
for (int i = 0; i < identifierEls.size(); i++) {
Element element = identifierEls.get(i);
Attribute attribute = element.getAttribute("type");
if (attribute.getValue().toLowerCase().equals("urn")) urn = element.getValue();
}
if (urn != null && urn.equals("")) urn = null;
return urn;
} catch (ValidityException ve) {
throw new IOException(ve);
} catch (ParsingException pe) {
throw new IOException(pe);
} catch (IOException ie) {
throw new IOException(ie);
} finally {
fileInputStream.close();
bomInputStream.close();
}
}
/**
* Decompress the gzipped content and process the resulting XML Sitemap.
*
* @param url - URL of the gzipped content
* @param response - Gzipped content
* @throws MalformedURLException
* @throws IOException
* @throws UnknownFormatException
*/
private AbstractSiteMap processGzip(URL url, byte[] response)
throws MalformedURLException, IOException, UnknownFormatException {
LOG.debug("Processing gzip");
AbstractSiteMap smi;
InputStream is = new ByteArrayInputStream(response);
// Remove .gz ending
String xmlUrl = url.toString().replaceFirst("\\.gz$", "");
LOG.debug("XML url = {}", xmlUrl);
BOMInputStream decompressed = new BOMInputStream(new GZIPInputStream(is));
InputSource in = new InputSource(decompressed);
in.setSystemId(xmlUrl);
smi = processXml(url, in);
decompressed.close();
return smi;
}