/**
* Performs an XPATH lookup in an xml document whose filename is specified by the first parameter
* (assumed to be in the auxiliary subdirectory) The XPATH expression is supplied as the second
* string parameter The return value is of type string e.g. this is currently used primarily for
* looking up the Company Prefix Index for encoding a GS1 Company Prefix into a 64-bit EPC tag
*/
private String xpathlookup(String xml, String expression) {
try {
// Parse the XML as a W3C document.
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document document =
builder.parse(new File(xmldir + File.separator + "auxiliary" + File.separator + xml));
XPath xpath = XPathFactory.newInstance().newXPath();
String rv = (String) xpath.evaluate(expression, document, XPathConstants.STRING);
return rv;
} catch (ParserConfigurationException e) {
System.err.println("ParserConfigurationException caught...");
e.printStackTrace();
return null;
} catch (XPathExpressionException e) {
System.err.println("XPathExpressionException caught...");
e.printStackTrace();
return null;
} catch (SAXException e) {
System.err.println("SAXException caught...");
e.printStackTrace();
return null;
} catch (IOException e) {
System.err.println("IOException caught...");
e.printStackTrace();
return null;
}
}
static {
try {
dbf.setNamespaceAware(true);
db = dbf.newDocumentBuilder();
xpath.setNamespaceContext(
new NamespaceContext() {
@Override
public Iterator<String> getPrefixes(String namespaceURI) {
return Arrays.asList("md").iterator();
}
@Override
public String getPrefix(String namespaceURI) {
return "md";
}
@Override
public String getNamespaceURI(String prefix) {
return "http://www.osgi.org/xmlns/metatype/v1.1.0";
}
});
} catch (ParserConfigurationException e) {
e.printStackTrace();
throw new ExceptionInInitializerError(e);
}
}