D-Net

package eu.dnetlib.repo.manager.service.utils;

import org.apache.log4j.Logger;

import org.dom4j.io.DOMWriter;

import org.w3c.dom.Document;

import se.kb.oai.pmh.*;

import se.kb.oai.pmh.Set;

import javax.net.ssl.*;

import javax.xml.namespace.NamespaceContext;

import javax.xml.xpath.XPath;

import javax.xml.xpath.XPathExpressionException;

import javax.xml.xpath.XPathFactory;

import java.security.KeyManagementException;

import java.security.NoSuchAlgorithmException;

import java.security.cert.X509Certificate;

import java.util.*;

public class OaiTools {

	{

		disableSslVerification();

	}

	private static Logger LOGGER = Logger.getLogger(OaiTools.class);

	public static List<String> getSetsOfRepo(String baseUrl) throws Exception {

		try {

			LOGGER.debug("Getting sets of repository " + baseUrl);

			OaiPmhServer harvester = new OaiPmhServer(baseUrl);

			SetsList setList = harvester.listSets();

			ResumptionToken token = setList.getResumptionToken();

			List<Set> sets = new ArrayList<Set>();

			sets.addAll(setList.asList());

			while (token != null) {

				setList = harvester.listSets(token);

				token = setList.getResumptionToken();

				sets.addAll(setList.asList());

			}

			List<String> ret = new ArrayList<String>();

			for (Set set : sets) {

				ret.add(set.getSpec().trim());

			}

			if (ret.size() > 0 )

				Collections.sort(ret);

			return ret;

		} catch (Exception e) {

			LOGGER.error("Error getting sets of repository " + baseUrl, e);

			return new ArrayList<String>();

			//throw e;

		}

	}

	public static boolean identifyRepository(String baseUrl) throws Exception {

		LOGGER.debug("sending identify request to repo " + baseUrl);

		OaiPmhServer harvester = new OaiPmhServer(baseUrl);

		if (baseUrl.trim().isEmpty()) {

			return false;

		}

		try {

			Identification identification = harvester.identify();

			DOMWriter d4Writer = new DOMWriter();

			Document d = d4Writer.write(identification.getResponse());

			return verifyIdentify(d);

		} catch (Exception e) {

			LOGGER.debug("Error verifying identify response", e);

			throw e;

		}

	}

	private static boolean verifyIdentify(Document doc) throws XPathExpressionException {

		NamespaceContext ctx = new NamespaceContext() {

			public String getNamespaceURI(String prefix) {

				String uri;

				if (prefix.equals("oai"))

					uri = "http://www.openarchives.org/OAI/2.0/";

				else

					uri = null;

				return uri;

			}

			// Dummy implementation - not used!

			public Iterator<String> getPrefixes(String val) {

				return null;

			}

			// Dummy implemenation - not used!

			public String getPrefix(String uri) {

				return null;

			}

		};

		// Now the XPath expression

		String xpathStr = "//oai:OAI-PMH/oai:Identify";

		XPathFactory xpathFact = XPathFactory.newInstance();

		XPath xpath = xpathFact.newXPath();

		xpath.setNamespaceContext(ctx);

		String result = xpath.evaluate(xpathStr, doc);

		return (result != null && !result.equals(""));

	}

	private static void disableSslVerification() {

		try

		{

			LOGGER.debug("disabling ssl verification");

			// Create a trust manager that does not validate certificate chains

			TrustManager[] trustAllCerts = new TrustManager[] {new X509TrustManager() {

				public X509Certificate[] getAcceptedIssuers() {

					return null;

				}

				public void checkClientTrusted(X509Certificate[] certs, String authType) {

				}

				public void checkServerTrusted(X509Certificate[] certs, String authType) {

				}

			}

			};

			// Install the all-trusting trust manager

			SSLContext sc = SSLContext.getInstance("SSL");

			sc.init(null, trustAllCerts, new java.security.SecureRandom());

			HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

			// Create all-trusting host name verifier

			HostnameVerifier allHostsValid = new HostnameVerifier() {

				public boolean verify(String hostname, SSLSession session) {

					return true;

				}

			};

			// Install the all-trusting host verifier

			HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);

		} catch (NoSuchAlgorithmException e) {

			LOGGER.error("disabling ssl verification", e);

		} catch (KeyManagementException e) {

			LOGGER.error("error while disabling ssl verification", e);

		}

	}

}