Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2009 University of New Mexico and the 

 *                  Regents of the University of California

 *

 *   '$Author: costa $'

 *     '$Date: 2009-07-27 17:47:44 -0400 (Mon, 27 Jul 2009) $'

 * '$Revision: 4999 $'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

 * 

 * Additional Copyright 2006 OCLC, Online Computer Library Center

 * 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.ucsb.nceas.metacat.oaipmh.harvester;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.net.URLEncoder;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.TransformerException;

import org.xml.sax.SAXException;

/**

 * This class represents an ListIdentifiers response on either the server or on

 * the client.

 * 

 * @author Duane Costa, University of New Mexico, LTER Network Office

 * @author Jeffrey A. Young, OCLC Online Computer Library Center

 */

public class ListIdentifiers extends HarvesterVerb {

/* Constructors */

  /**

   * Mock object constructor (for unit testing purposes)

   */

  public ListIdentifiers() {

    super();

  }

  /**

   * Client-side ListIdentifiers verb constructor

   * 

   * @param baseURL                baseURL of the OAI-PMH provider to be queried

   * @param from                   the from date, e.g. "2000-01-01"

   * @param until                  the until date. e.g. "2009-12-31"

   * @param metadataPrefix         the metadata prefix, e.g. "oai_pmh"

   * @param setSpec                the set specifier

   * 

   * @exception MalformedURLException  the baseURL is bad

   * @exception SAXException           the xml response is bad

   * @exception IOException            an I/O error occurred

   */

  public ListIdentifiers(String baseURL, String from, String until, 

                         String metadataPrefix, String setSpec) 

          throws IOException, ParserConfigurationException,

      SAXException, TransformerException {

    super(getRequestURL(baseURL, from, until, metadataPrefix, setSpec));

  }

  /**

   * Client-side ListIdentifiers verb constructor (resumptionToken version)

   * 

   * @param baseURL                baseURL of the OAI-PMH provider to be queried

   * @param resumptionToken        the resumptionToken string, as returned by

   *                               the provider server

   * @throws IOException

   * @throws ParserConfigurationException

   * @throws SAXException

   * @throws TransformerException

   */

  public ListIdentifiers(String baseURL, String resumptionToken)

      throws IOException, ParserConfigurationException, SAXException,

      TransformerException {

    super(getRequestURL(baseURL, resumptionToken));

  }

/* Class methods */

  /**

   * Construct the query portion of the http request (non-resumptionToken 

   * version)

   * @param baseURL                baseURL of the OAI-PMH provider to be queried

   * @param from                   the from date, e.g. "2000-01-01"

   * @param until                  the until date. e.g. "2009-12-31"

   * @param metadataPrefix         the metadata prefix, e.g. "oai_pmh"

   * @param setSpec                the set specifier

   * 

   * @return a String containing the query portion of the http request

   */

  private static String getRequestURL(String baseURL, String from,

                                      String until, String metadataPrefix,

                                      String setSpec)

  {

    StringBuffer stringBuffer = new StringBuffer(baseURL);

    stringBuffer.append("?verb=ListIdentifiers");

    if (from != null) stringBuffer.append("&from=").append(from);

    if (until != null) stringBuffer.append("&until=").append(until);

    if (setSpec != null) stringBuffer.append("&set=").append(setSpec);

    stringBuffer.append("&metadataPrefix=").append(metadataPrefix);

    String requestURL = stringBuffer.toString();

    return requestURL;

  }

  /**

   * Construct the query portion of the http request (resumptionToken version)

   * 

   * @param baseURL                baseURL of the OAI-PMH provider to be queried

   * @param resumptionToken        the resumptionToken string, as returned by

   *                               the provider server

   * @return a String containing the query portion of the http request

   */

  private static String getRequestURL(String baseURL, String resumptionToken) 

          throws UnsupportedEncodingException 

  {

    StringBuffer stringBuffer = new StringBuffer(baseURL);

    stringBuffer.append("?verb=ListIdentifiers");

    stringBuffer.append("&resumptionToken=");

    stringBuffer.append(URLEncoder.encode(resumptionToken, "UTF-8"));

    String requestURL = stringBuffer.toString();

    return requestURL;

  }

  /* Instance methods */

  /**

   * Get the oai:resumptionToken from the response

   * 

   * @return the oai:resumptionToken value

   * @throws TransformerException

   * @throws NoSuchFieldException

   */

  public String getResumptionToken() 

          throws TransformerException, NoSuchFieldException 

  {

    String schemaLocation = getSchemaLocation();

    String resumptionToken = "";

    if (SCHEMA_LOCATION_V2_0.equals(schemaLocation)) {

      resumptionToken = getSingleString(

                    "/oai20:OAI-PMH/oai20:ListIdentifiers/oai20:resumptionToken"

                                       );

    } 

    else {

      throw new NoSuchFieldException(getSchemaLocation());

    }

    return resumptionToken;

  }

}