Metacat

Crosswalks.eml-2.1.1=edu.ucsb.nceas.metacat.oaipmh.provider.server.crosswalk.Eml211

/**

 * 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.provider.server.crosswalk;

import java.util.HashMap;

import java.util.Properties;

import org.apache.log4j.Logger;

import ORG.oclc.oai.server.crosswalk.Crosswalk;

import ORG.oclc.oai.server.verb.CannotDisseminateFormatException;

import ORG.oclc.oai.server.verb.OAIInternalServerError;

/**

 * Provides eml-2.1.1 documents. We simply return the metadata that was read 

 * from Metacat.

 */

public class Eml211 extends Crosswalk {

  /* Class fields */

  private static final Logger logger = Logger.getLogger(Eml211.class);

  private static final String SCHEMA_LOCATION =

    "eml://ecoinformatics.org/eml-2.1.1 " +

    "http://knb.ecoinformatics.org/knb/schema/eml-2.1.1/eml.xsd";

  /* Constructors */

  /**

   * The constructor assigns the schemaLocation associated with this crosswalk.

   * Since the crosswalk is trivial in this case, no properties are utilized.

   * 

   * @param properties

   *          properties that are needed to configure the crosswalk.

   */

  public Eml211(Properties properties) throws OAIInternalServerError {

    super(SCHEMA_LOCATION);

  }

  /* Class methods */

  /* Instance methods */

  /**

   * Perform the actual crosswalk.

   * 

   * @param nativeItem  A HashMap object that contains the EML string that was

   *                    retrieved from Metacat and stored as the value of the

   *                    "recordBytes" key

   *                    

   * @return emlDoc  a String containing the metadata to be stored within 

   *                    the <metadata> element

   *                    

   * @exception CannotDisseminateFormatException

   *                    nativeItem doesn't support this format.

   */

  public String createMetadata(Object nativeItem)

      throws CannotDisseminateFormatException {

    HashMap recordMap = (HashMap) nativeItem;

    String xmlRec = (String) recordMap.get("recordBytes");    

    String emlDoc = xmlRec.trim();

    /*

     * Remove leading XML processing instructions because the document is going

     * to be placed inside an OAI <metadata> element.

     */

    while (emlDoc.startsWith("<?")) {

      int offset = emlDoc.indexOf("?>");

      emlDoc = emlDoc.substring(offset + 2).trim();

    }

    return emlDoc;

  }

  /**

   * Can this nativeItem be represented in 'eml-2.1.1' format?

   * 

   * @param nativeItem              a record in native format

   * @return true if 'eml-2.1.1' format is possible, false otherwise.

   */

  public boolean isAvailableFor(Object nativeItem) {

    boolean isAvailable = false;

    HashMap recordMap = (HashMap) nativeItem;

    String doctype = (String) recordMap.get("doctype");

    if (doctype.equals("eml://ecoinformatics.org/eml-2.1.1")) {

      isAvailable = true;

    }

    return isAvailable;

  }

}