AccessClient.java

/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.unc.lib.dl.fedora;

import static edu.unc.lib.dl.fedora.AuthorizationException.AuthorizationErrorType.INDETERMINATE;
import static edu.unc.lib.dl.fedora.AuthorizationException.AuthorizationErrorType.NOT_APPLICABLE;

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.springframework.oxm.jaxb.Jaxb2Marshaller;
import org.springframework.ws.WebServiceMessage;
import org.springframework.ws.client.WebServiceFaultException;
import org.springframework.ws.client.WebServiceIOException;
import org.springframework.ws.client.core.WebServiceMessageCallback;
import org.springframework.ws.client.core.WebServiceTemplate;
import org.springframework.ws.soap.SoapMessage;
import org.springframework.ws.soap.client.SoapFaultClientException;
import org.springframework.ws.soap.saaj.SaajSoapMessageFactory;
import org.springframework.ws.transport.http.HttpComponentsMessageSender;

import edu.unc.lib.dl.fedora.types.ArrayOfString;
import edu.unc.lib.dl.fedora.types.DescribeRepository;
import edu.unc.lib.dl.fedora.types.DescribeRepositoryResponse;
import edu.unc.lib.dl.fedora.types.FieldSearchQuery;
import edu.unc.lib.dl.fedora.types.FindObjects;
import edu.unc.lib.dl.fedora.types.FindObjectsResponse;
import edu.unc.lib.dl.fedora.types.GetDatastreamDissemination;
import edu.unc.lib.dl.fedora.types.GetDatastreamDisseminationResponse;
import edu.unc.lib.dl.fedora.types.GetObjectProfile;
import edu.unc.lib.dl.fedora.types.GetObjectProfileResponse;
import edu.unc.lib.dl.fedora.types.MIMETypedStream;
import edu.unc.lib.dl.fedora.types.ObjectFields;
import edu.unc.lib.dl.fedora.types.ObjectProfile;

/**
 * The AccessClient is a Fedora 3.0 API-A SOAP client bean. After the fedoraUrl, username and password properties are
 * set, call the init() method before using it.
 * <p>
 * For Fedora 3.0 API documentation, please consult the <a
 * href="https://fedora-commons.org/confluence/display/FCR30/API-A">wiki</a>.
 * </p>
 *
 * @author count0
 *
 */
public class AccessClient extends WebServiceTemplate {
	/**
	 * These are the actions support by the Fedora API-A service.
	 *
	 * @author count0
	 *
	 */
	private enum Action {
		describeRepository("describeRepository"), findObjects("findObjects"), getDatastreamDissemination(
				"getDatastreamDissemination"), getObjectProfile("getObjectProfile");
		String uri = null;

		Action(String action) {
			uri = "http://www.fedora.info/definitions/1/0/api/#" + action;
		}

		WebServiceMessageCallback callback() {
			return new WebServiceMessageCallback() {
				@Override
				public void doWithMessage(WebServiceMessage message) {
					((SoapMessage) message).setSoapAction(uri);
				}
			};
		}
	}

	private static final Log log = LogFactory.getLog(AccessClient.class);
	private String fedoraContextUrl;
	private String password;
	private String username;

	/**
	 * Encapsulates all marshalled web service calls.
	 *
	 * @param request
	 *           a marshalled request object
	 * @param action
	 *           the Fedora API-A action
	 * @return an unmarshalled response object
	 */
	private Object callService(Object request, Action action) throws FedoraException {
		return callService(request, action, true);
	}

	private Object callService(Object request, Action action, boolean retry) throws FedoraException {
		Object response = null;
		try {
			response = this.marshalSendAndReceive(request, action.callback());
		} catch (WebServiceIOException e) {
			if (e.getMessage().contains("503")) {
				throw new FedoraTimeoutException(e);
			} else if (java.net.SocketTimeoutException.class.isInstance(e.getCause())) {
				throw new FedoraTimeoutException(e);
			} else {
				throw new ServiceException(e);
			}
		} catch (SoapFaultClientException e) {
			try {
				FedoraFaultMessageResolver.resolveFault(e);
			} catch (AuthorizationException ae) {
				if (retry && (NOT_APPLICABLE.equals(ae.getType()) || INDETERMINATE.equals(ae.getType()))) {
					log.warn("Authorization failed, attempting to reestablish connection to Fedora.");
					try {
						this.init();
					} catch (Exception e1) {
						log.error("Failed to reestablish connection to Fedora", e);
						throw ae;
					}
					return callService(request, action, false);
				}

				throw ae;
			}
		} catch (WebServiceFaultException e) {
			throw new ServiceException(e);
		}
		return response;
	}

	public DescribeRepositoryResponse describeRepository(DescribeRepository o) throws ServiceException, FedoraException {
		DescribeRepositoryResponse response = (DescribeRepositoryResponse) this.callService(o, Action.describeRepository);
		return response;
	}

	public List<PID> findAllObjectPIDs() throws FedoraException, ServiceException {
		List<PID> result = new ArrayList<PID>();
		FindObjects fo = new FindObjects();
		fo.setMaxResults(BigInteger.valueOf(100000));
		FieldSearchQuery query = new FieldSearchQuery();
		fo.setQuery(query);
		ArrayOfString fields = new ArrayOfString();
		fields.getItem().add("pid");
		fo.setResultFields(fields);
		FindObjectsResponse response = (FindObjectsResponse) this.callService(fo, Action.findObjects);
		for (ObjectFields o : response.getResult().getResultList().getObjectFields()) {
			String s = o.getPid().getValue();
			result.add(new PID(s));
		}
		return result;
	}

	public MIMETypedStream getDatastreamDissemination(PID pid, String dsid, String timestamp) throws FedoraException,
			ServiceException {
		GetDatastreamDissemination req = new GetDatastreamDissemination();
		req.setPid(pid.getPid());
		// TODO: test that NotFoundException is throw for non-existant datastreams
		req.setDsID(dsid);
		if (timestamp != null) {
			req.setAsOfDateTime(timestamp);
		}
		GetDatastreamDisseminationResponse response = (GetDatastreamDisseminationResponse) this.callService(req,
				Action.getDatastreamDissemination);
		return response.getDissemination();
	}

	public ObjectProfile getObjectProfile(PID pid, String timestamp) throws FedoraException, ServiceException {
		GetObjectProfile req = new GetObjectProfile();
		req.setPid(pid.getPid());
		if (timestamp != null) {
			req.setAsOfDateTime(timestamp);
		}
		GetObjectProfileResponse response = (GetObjectProfileResponse) this.callService(req, Action.getObjectProfile);
		return response.getObjectProfile();
	}

	/**
	 * Get the Fedora base URL.
	 *
	 * @return Fedora base URL
	 */
	public String getFedoraContextUrl() {
		return fedoraContextUrl;
	}

	/**
	 * Get the Fedora password.
	 *
	 * @return
	 */
	public String getPassword() {
		return password;
	}

	/**
	 * Get the Fedora username
	 *
	 * @return
	 */
	public String getUsername() {
		return username;
	}

	/**
	 * Initializes this client bean, calling the initializers of dependencies.
	 *
	 * @throws Exception
	 *            when initialization fails
	 */
	public void init() throws Exception {
		SaajSoapMessageFactory msgFactory = new SaajSoapMessageFactory();
		msgFactory.afterPropertiesSet();
		this.setMessageFactory(msgFactory);

		Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
		marshaller.setContextPath("edu.unc.lib.dl.fedora.types");
		marshaller.afterPropertiesSet();
		this.setMarshaller(marshaller);
		this.setUnmarshaller(marshaller);

		HttpComponentsMessageSender sender = new HttpComponentsMessageSender();
		UsernamePasswordCredentials credentials = new UsernamePasswordCredentials(this.username, this.password);
		sender.setCredentials(credentials);
		sender.afterPropertiesSet();
		this.setMessageSender(sender);

		// this.setFaultMessageResolver(new FedoraFaultMessageResolver());
		this.setDefaultUri(this.getFedoraContextUrl() + "/services/access");
		this.afterPropertiesSet();
	}

	/**
	 * Set the Fedora base URL.
	 *
	 * @param fedoraUrl
	 */
	public void setFedoraContextUrl(String fedoraContextUrl) {
		this.fedoraContextUrl = fedoraContextUrl;
	}

	/**
	 * Set the Fedora password.
	 *
	 * @param password
	 */
	public void setPassword(String password) {
		this.password = password;
	}

	/**
	 * Set the Fedora username
	 *
	 * @param username
	 */
	public void setUsername(String username) {
		this.username = username;
	}
}