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The Fedora Client is a Java Library that allows API access to a Fedora Repository. The client is typically one part of a full Fedora installation.
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/*
 * -----------------------------------------------------------------------------
 *
 * License and Copyright: The contents of this file are subject to 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.fedora-commons.org/licenses.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
 * the specific language governing rights and limitations under the License.
 *
 * The entire file consists of original code.
 * Copyright © 2008 Fedora Commons, Inc.

 * 
Copyright © 2002-2007 The Rector and Visitors of the University of 
 * Virginia and Cornell University
 
 * All rights reserved.
 *
 * -----------------------------------------------------------------------------
 */
package fedora.server.access.defaultdisseminator;

import java.util.ArrayList;
import java.io.File;
import java.io.InputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Properties;
import java.util.Date;

import fedora.server.Context;
import fedora.server.access.Access;
import fedora.server.access.ObjectProfile;
import fedora.server.errors.ServerException;
import fedora.server.errors.DisseminationException;
import fedora.server.errors.GeneralException;
import fedora.server.errors.ObjectIntegrityException;
import fedora.server.storage.DOReader;
import fedora.server.storage.types.DatastreamXMLMetadata;
import fedora.server.storage.types.MethodDef;
import fedora.server.storage.types.MethodParmDef;
import fedora.server.storage.types.MIMETypedStream;
import fedora.server.storage.types.ObjectMethodsDef;
import fedora.server.access.defaultdisseminator.ObjectInfoAsXML;

import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

/**
 * Title: DefaultDisseminatorImpl.java
 * Description: Implements the methods defined in the DefaultDisseminator interface.
 * This is the default behavior mechanism that implements the "contract" of
 * the default behavior definition that is dynamically associated with every
 * digital object in the repository.
 *
 * This class is considered an "internal service" that is built in to the
 * Fedora system.  Its purpose is to endow every digital object with a set of
 * generic behaviors.  It is an implementation of what is known as the
 * Default Disseminator.
 *
 * Unlike other behavior definitions and mechanisms, there is no Behavior
 * Definition Object or Behavior Mechanism Object stored in the repository. 
 *
 * @author [email protected]
 * @version $Id: DefaultDisseminatorImpl.java 5087 2006-09-30 11:57:05Z eddie $
 */
public class DefaultDisseminatorImpl extends InternalService implements DefaultDisseminator

{
  private Context context;
  private String PID;
  private Date asOfDateTime;
  private DOReader reader;
  private String reposBaseURL;
  private File reposHomeDir;
  private Access m_access;

  public DefaultDisseminatorImpl(Context context, Date asOfDateTime,
    DOReader reader, Access access, String reposBaseURL, File reposHomeDir)
    throws ServerException
  {
    this.context = context;
    this.asOfDateTime = asOfDateTime;
    this.reader = reader;
    this.m_access = access;
    this.reposBaseURL = reposBaseURL;
    this.reposHomeDir = reposHomeDir;

  }

  /**
   * Returns an HTML rendering of the object profile which contains
   * key metadata from the object, plus URLs for the object's Dissemination
   * Index and Item Index.  The data is returned as HTML in a
   * presentation-oriented format.  This is accomplished by doing an XSLT
   * transform on the XML that is obtained from getObjectProfile in API-A.
   * @return  html packaged as a MIMETypedStream
   * @throws ServerException
   */
  public MIMETypedStream viewObjectProfile() throws ServerException
  {
    try
    {
		ObjectProfile profile = m_access.getObjectProfile(context, reader.GetObjectPID(), asOfDateTime);
		InputStream in = null;
		try
		{
		  in = new ByteArrayInputStream(
		  (new ObjectInfoAsXML().getObjectProfile(reposBaseURL, profile, asOfDateTime).getBytes("UTF-8")));
		} catch (UnsupportedEncodingException uee)
		{
		  throw new GeneralException("[DefaultDisseminatorImpl] An error has occurred. "
			  + "The error was a \"" + uee.getClass().getName() + "\"  . The "
			  + "Reason was \"" + uee.getMessage() + "\"  .");
		}
      //InputStream in = getObjectProfile().getStream();
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      File xslFile = new File(reposHomeDir, "access/viewObjectProfile.xslt");
      TransformerFactory factory = TransformerFactory.newInstance();
      Templates template = factory.newTemplates(new StreamSource(xslFile));
      Transformer transformer = template.newTransformer();
      Properties details = template.getOutputProperties();
      transformer.transform(new StreamSource(in), new StreamResult(out));
      in = new ByteArrayInputStream(out.toByteArray());
      return new MIMETypedStream("text/html", in, null);
    } catch (TransformerException e)
    {
      throw new DisseminationException("[DefaultDisseminatorImpl] had an error "
          + "in transforming xml for viewObjectProfile. "
          + "Underlying exception was: "
          + e.getMessage());
    }
  }

  /**
   * Returns an HTML rendering of the Dissemination Index for the object.
   * The Dissemination Index is a list of method definitions that represent
   * all disseminations possible on the object.  The Dissemination Index
   * is returned as HTML in a presentation-oriented format.  This is
   * accomplished by doing an XSLT transform on the XML that is
   * obtained from listMethods in API-A.
   * @return  html packaged as a MIMETypedStream
   * @throws ServerException
   */
  public MIMETypedStream viewMethodIndex() throws ServerException
  {
    // sdp: the dissemination index is disabled for bdef and bmech objects
    // so send back a message saying so.
    if ((reader.getFedoraObjectType().equalsIgnoreCase("D")) ||
        (reader.getFedoraObjectType().equalsIgnoreCase("M")))
    {
      return noMethodIndexMsg();
    }

	// get xml expression of method definitions
	ObjectMethodsDef[] methods =
	    m_access.listMethods(context, reader.GetObjectPID(), asOfDateTime);
	InputStream in = null;
	try
	{
	  in = new ByteArrayInputStream(
	  (new ObjectInfoAsXML().getMethodIndex(
		reposBaseURL, reader.GetObjectPID(), methods, asOfDateTime).getBytes("UTF-8")));
	} catch (UnsupportedEncodingException uee)
	{
	  throw new GeneralException("[DefaultDisseminatorImpl] An error has occurred. "
		  + "The error was a \"" + uee.getClass().getName() + "\"  . The "
		  + "Reason was \"" + uee.getMessage() + "\"  .");
	}

	// transform the method definitions xml to an html view
    try
    {
      //InputStream in = getMethodIndex().getStream();
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      //File xslFile = new File(reposHomeDir, "access/objectMethods.xslt");
	  File xslFile = new File(reposHomeDir, "access/viewObjectMethods.xslt");
      TransformerFactory factory = TransformerFactory.newInstance();
      Templates template = factory.newTemplates(new StreamSource(xslFile));
      Transformer transformer = template.newTransformer();
      Properties details = template.getOutputProperties();
      transformer.transform(new StreamSource(in), new StreamResult(out));
      in = new ByteArrayInputStream(out.toByteArray());
      return new MIMETypedStream("text/html", in, null);
    } catch (TransformerException e)
    {
      throw new DisseminationException("[DefaultDisseminatorImpl] had an error "
          + "in transforming xml for viewItemIndex. "
          + "Underlying exception was: "
          + e.getMessage());
    }
  }

  /**
   * Returns an HTML rendering of the Item Index for the object.  The Item
   * Index is a list of all datastreams in the object.  The datastream items
   * can be data or metadata.  The Item Index is returned as HTML in a
   * presentation-oriented format.  This is accomplished by doing an XSLT
   * transform on the XML that is obtained from listDatastreams in API-A.
   * @return  html packaged as a MIMETypedStream
   * @throws ServerException
   */
  public MIMETypedStream viewItemIndex() throws ServerException
  {
	// get the item index as xml  	
	InputStream in = null;
	try{
	in = new ByteArrayInputStream(
	  new ObjectInfoAsXML().getItemIndex(
	  reposBaseURL, reader, asOfDateTime).getBytes("UTF-8"));
  	} catch (Exception e)
  		{
			throw new GeneralException("[DefaultDisseminatorImpl] An error has occurred. "
			+ "The error was a \"" + e.getClass().getName() + "\"  . The "
			+ "Reason was \"" + e.getMessage() + "\"  .");
  	}

	// convert the xml to an html view	
    try
    {
      //InputStream in = getItemIndex().getStream();
      ByteArrayOutputStream out = new ByteArrayOutputStream();
      File xslFile = new File(reposHomeDir, "access/viewItemIndex.xslt");
      TransformerFactory factory = TransformerFactory.newInstance();
      Templates template = factory.newTemplates(new StreamSource(xslFile));
      Transformer transformer = template.newTransformer();
      Properties details = template.getOutputProperties();
      transformer.transform(new StreamSource(in), new StreamResult(out));
      in = new ByteArrayInputStream(out.toByteArray());
      return new MIMETypedStream("text/html", in, null);
    } catch (TransformerException e)
    {
      throw new DisseminationException("[DefaultDisseminatorImpl] had an error "
          + "in transforming xml for viewItemIndex. "
          + "Underlying exception was: "
          + e.getMessage());
    }
  }
  
  /**
   * Returns the Dublin Core record for the object, if one exists.
   * The record is returned as HTML in a presentation-oriented format.
   * @return  html packaged as a MIMETypedStream
   * @throws ServerException
   */
  public MIMETypedStream viewDublinCore() throws ServerException
  {
	// get dublin core record as xml 	
	DatastreamXMLMetadata dcmd = null;
	InputStream in = null;
	try
	{
		dcmd = (DatastreamXMLMetadata) reader.GetDatastream("DC", asOfDateTime);
		in = new ByteArrayInputStream(
			 new ObjectInfoAsXML().getOAIDublinCore(dcmd).getBytes("UTF-8"));
	} catch (ClassCastException cce)
	{
		throw new ObjectIntegrityException("Object " + reader.GetObjectPID()
			+ " has a DC datastream, but it's not inline XML.");

	} catch (UnsupportedEncodingException uee)
	{
		throw new GeneralException("[DefaultDisseminatorImpl] An error has occurred. "
			+ "The error was a \"" + uee.getClass().getName() + "\"  . The "
			+ "Reason was \"" + uee.getMessage() + "\"  .");
	}
	
	// convert the dublin core xml to an html view	
	try
	{
	  //InputStream in = getDublinCore().getStream();
	  ByteArrayOutputStream out = new ByteArrayOutputStream();
	  File xslFile = new File(reposHomeDir, "access/viewDublinCore.xslt");
	  TransformerFactory factory = TransformerFactory.newInstance();
	  Templates template = factory.newTemplates(new StreamSource(xslFile));
	  Transformer transformer = template.newTransformer();
	  Properties details = template.getOutputProperties();
	  transformer.transform(new StreamSource(in), new StreamResult(out));
	  in = new ByteArrayInputStream(out.toByteArray());
	  return new MIMETypedStream("text/html", in, null);
	} catch (TransformerException e)
	{
	  throw new DisseminationException("[DefaultDisseminatorImpl] had an error "
		  + "in transforming xml for viewDublinCore. "
		  + "Underlying exception was: "
		  + e.getMessage());
	}
  }

  private MIMETypedStream noMethodIndexMsg() throws GeneralException
  {
	  String msg = new String("The Dissemination Index is not available"
		+ " for Behavior Definition or Behavior Mechanism objects."
		+ " The addition of this feature is not currently scheduled.");
	  StringBuffer sb = new StringBuffer();
	  sb.append("Dissemination Index Not Available");
	  sb.append("");
	  sb.append("");
	  sb.append("");
	  sb.append(" ");
	  sb.append("Fedora Repository");
	  sb.append("Dissemination Index");
	  sb.append("");
	  sb.append("" + msg + "");
	  sb.append("");
	  sb.append("");
	  String msgOut = sb.toString();
	  ByteArrayInputStream in = null;
	  try
	  {
		in = new ByteArrayInputStream(msgOut.getBytes("UTF-8"));
	  }
	  catch (UnsupportedEncodingException uee)
	  {
		throw new GeneralException("[DefaultDisseminatorImpl] An error has occurred. "
			+ "The error was a \"" + uee.getClass().getName() + "\"  . The "
			+ "Reason was \"" + uee.getMessage() + "\"  .");
	  }
	  return new MIMETypedStream("text/html", in, null);
  }

  /**
   * Method implementation of reflectMethods from the InternalService interface.
   * This will return an array of method definitions that constitute the
   * behaviors of the Default Disseminator which is associated with every 
   * Fedora object.  These will be the methods promulgated by the DefaultDisseminator 
   * interface. 
   * @return  an array of method defintions
   */
  public static MethodDef[] reflectMethods()
  {
    ArrayList methodList = new ArrayList();
    MethodDef method = null;

    method = new MethodDef();
    method.methodName = "viewObjectProfile";
    method.methodLabel = "View description of the object";
    method.methodParms = new MethodParmDef[0];
    methodList.add(method);

    method = new MethodDef();
    method.methodName = "viewMethodIndex";
    method.methodLabel = "View a list of dissemination methods in the object";
    method.methodParms = new MethodParmDef[0];
    methodList.add(method);

    method = new MethodDef();
    method.methodName = "viewItemIndex";
    method.methodLabel = "View a list of items in the object";
    method.methodParms = new MethodParmDef[0];
    methodList.add(method);
    

	method = new MethodDef();
	method.methodName = "viewDublinCore";
	method.methodLabel = "View the Dublin Core record for the object";
	method.methodParms = new MethodParmDef[0];
	methodList.add(method);

	// DEPRECATED in Fedora 2.0.  Will be removed in Fedora 2.1.
	/**
    method = new MethodDef();
    method.methodName = "getItem";
    method.methodLabel = "Get an item from the object";
    method.methodParms = new MethodParmDef[1];
    method.methodParms[0] = new MethodParmDef();
    method.methodParms[0].parmName = "itemID";
    method.methodParms[0].parmType = MethodParmDef.USER_INPUT;
    method.methodParms[0].parmLabel = "Item identifier in format of datastream ID";
    method.methodParms[0].parmRequired = true;
    method.methodParms[0].parmPassBy = MethodParmDef.PASS_BY_VALUE;
    method.methodParms[0].parmDefaultValue = null;
    method.methodParms[0].parmDomainValues = new String[0];
    methodList.add(method);
    **/
    
	return (MethodDef[])methodList.toArray(new MethodDef[0]);

  }
}