D-Net

package eu.dnetlib.utils;

import java.io.StringReader;

import java.io.StringWriter;

import java.util.HashMap;

import java.util.Iterator;

import javax.xml.XMLConstants;

import javax.xml.namespace.NamespaceContext;

import javax.xml.namespace.QName;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.stream.StreamResult;

import javax.xml.transform.stream.StreamSource;

import javax.xml.ws.Endpoint;

import javax.xml.ws.wsaddressing.W3CEndpointReference;

import javax.xml.ws.wsaddressing.W3CEndpointReferenceBuilder;

import javax.xml.xpath.XPath;

import javax.xml.xpath.XPathConstants;

import javax.xml.xpath.XPathExpression;

import javax.xml.xpath.XPathExpressionException;

import javax.xml.xpath.XPathFactory;

import org.apache.log4j.Logger;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

import org.xml.sax.InputSource;

import eu.dnetlib.domain.EPR;

import eu.dnetlib.soap.EndpointReferenceBuilder;

public class EPRUtils {

	private static final String REFERENCE_PARAMETER_NS = "http://www.driver.org";

	private static XPathExpression ADDRESS_EXPR = null;

	private static XPathExpression REFERENCE_PARAMETER_EXPR = null;

	static {

		XPathFactory factory = XPathFactory.newInstance();

		XPath xpath = factory.newXPath();

		xpath.setNamespaceContext(new RSClientNSContext());

		try {

			REFERENCE_PARAMETER_EXPR = xpath.compile("//wsa:ReferenceParameters");

			ADDRESS_EXPR = xpath.compile("//wsa:Address");

		} catch (XPathExpressionException e) {

			throw new RuntimeException("Failed to build xpath expression.", e);

		}

	}

	private static Logger logger = Logger.getLogger(EPRUtils.class);

	public static EPR createEPR(W3CEndpointReference w3cEpr) {

		try {

			StringWriter writer = new StringWriter();

			w3cEpr.writeTo(new StreamResult(writer));

			EPR epr = new EPR();

			Node node = null;

			String address = null;

			synchronized (EPRUtils.class) {

				node = (Node) REFERENCE_PARAMETER_EXPR.evaluate(new InputSource(new StringReader(writer.toString())), XPathConstants.NODE);

				address = (String) ADDRESS_EXPR.evaluate(new InputSource(new StringReader(writer.toString())));	

			}

			if (node != null && node.getChildNodes() != null) {

				for (int i = 0; i < node.getChildNodes().getLength(); i++) {

					Node child = node.getChildNodes().item(i);

					if (child.getNamespaceURI() != null && 

							child.getNamespaceURI().equals(REFERENCE_PARAMETER_NS)) {

						String name = child.getLocalName();

						String value = child.getTextContent();

						if (logger.isDebugEnabled())

							logger.debug("Found parameter " + name + ": " + value);

						epr.setParameter(name, value);

					}

				}

			}

			epr.setAddress(address);

			epr.setEpr(writer.toString());

			return epr;

		} catch (XPathExpressionException e) {

			logger.error("Error parsing epr", e);

			e.printStackTrace();

		}

		return null;

	}

	public static W3CEndpointReference createW3CEPR(EPR epr) {

		W3CEndpointReference w3cEpr = null;

		if (epr.getEpr() != null) {

			StringReader reader = new StringReader(epr.getEpr());

			w3cEpr = new W3CEndpointReference(new StreamSource(reader));

		} else {

			StringWriter writer = new StringWriter();

			w3cEpr = buildW3CEpr(epr);

			w3cEpr.writeTo(new StreamResult(writer));

			epr.setEpr(writer.toString());

		}

		return w3cEpr;

	}

	public static W3CEndpointReference createW3CEPR(EndpointReferenceBuilder<Endpoint> builder, Endpoint endpoint) {

		W3CEndpointReference w3cepr = builder.getEndpointReference(endpoint);

		return w3cepr;

	}

	public static EPR createEPR(EndpointReferenceBuilder<Endpoint> builder,

			Endpoint endpoint) {

		EPR epr = null;

		if (logger.isDebugEnabled()) {

			logger.debug("Creating epr for " + endpoint.getImplementor().getClass());

		}

		epr = createEPR(createW3CEPR(builder, endpoint));

		if (logger.isDebugEnabled()) {

			logger.debug("Created epr: " + epr);

		}

		return epr;

	}

	public static String eprToXml(final EPR epr) {

		/************************************************************************************************

		 * WARNING: Avoid using cached XML string because it can not be parsed again safely. If the		*

		 * W3C EPR generated by parsing the cached XML string is serialized again back to XML, the		*

		 * builder keeps adding namespaces (basically the same namespace URI with just different		*

		 * namespace prefix). As a consequence															*

		 * 																							 	*

		 * EPRUtils.eprToXml(epr).equals(EPRUtils.eprToXml(EPRUtils.xmlToEpr(EPRUtils.eprToXml(epr))))	*

		 * 																								*

		 * would always be false for any given EPR epr.													*

		 * **********************************************************************************************/

		epr.setEpr(null);

		final StringWriter xml = new StringWriter();

		createW3CEPR(epr).writeTo(new StreamResult(xml));

		return xml.toString();

	}

	public static EPR xmlToEpr(final String xml) {

		return createEPR((W3CEndpointReference) W3CEndpointReference.readFrom(new StreamSource(new StringReader(xml))));

	}

	private static W3CEndpointReference buildW3CEpr(EPR epr) {

		try {

			W3CEndpointReferenceBuilder builder = new W3CEndpointReferenceBuilder();

			Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();

			builder.address(epr.getAddress());

			builder.serviceName(new QName(REFERENCE_PARAMETER_NS, "serviceName"));

			for (String name:epr.getParameterNames()) {

				Element element = doc.createElementNS(REFERENCE_PARAMETER_NS, name);

				element.setTextContent(epr.getParameter(name));

				builder.referenceParameter(element);

			}

			return builder.build();

		} catch (ParserConfigurationException e) {

			e.printStackTrace();

		}

		return null;

	}

}

class RSClientNSContext implements NamespaceContext {

	HashMap<String, String> prefixes = null;

	public String getNamespaceURI(String prefix) {

		if (prefixes == null) {

			prefixes = new HashMap<String, String>();

			prefixes.put("wsa", "http://www.w3.org/2005/08/addressing");

			prefixes.put("driver", "http://www.driver.org");

			prefixes.put("wsaw", "http://www.w3.org/2006/05/addressing/wsdl");

			prefixes.put("wsdli", "http://www.w3.org/2005/08/wsdl-instance");

		}

		if (prefix == null) {

			throw new NullPointerException("Null prefix");

		} else {

			prefix = prefixes.get(prefix);

			if (prefix == null) {

				return XMLConstants.DEFAULT_NS_PREFIX;

			} else {

				return prefix;

			}

		}

	}

	public String getPrefix(String namespaceURI) {

		throw new UnsupportedOperationException();

	}

	public Iterator<String> getPrefixes(String namespaceURI) {

		throw new UnsupportedOperationException();

	}

}