java.fedora.server.access.DynamicAccessImpl Maven / Gradle / Ivy
/*
* -----------------------------------------------------------------------------
*
* 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;
import java.util.Date;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Hashtable;
import java.io.File;
import java.lang.Class;
import java.lang.reflect.*;
import fedora.common.Constants;
import fedora.server.Context;
import fedora.server.Module;
import fedora.server.access.defaultdisseminator.DefaultDisseminatorImpl;
import fedora.server.access.defaultdisseminator.ServiceMethodDispatcher;
import fedora.server.errors.MethodNotFoundException;
import fedora.server.errors.GeneralException;
import fedora.server.errors.ServerException;
import fedora.server.search.FieldSearchQuery;
import fedora.server.search.FieldSearchResult;
import fedora.server.storage.DOReader;
import fedora.server.storage.types.DatastreamDef;
import fedora.server.storage.types.MethodDef;
import fedora.server.storage.types.MIMETypedStream;
import fedora.server.storage.types.ObjectMethodsDef;
import fedora.server.storage.types.Property;
/**
* Title: DynamicAccessImpl.java
* Description: The implementation of the Dynamic Access module.
* The Dynamic Access module will associate dynamic disseminators with
* the a digital object. It will look to the Fedora repository configuration
* file to obtain a list of dynamic disseminators. Currently, the system
* supports two types of dynamic disseminators:
* - Default (BDefPID=fedora-system:3 and BMechPID=fedora-system:4)
* - Bootstrap (BDefPID=fedora-system:1 and BMechPID=fedora-system:2).
* The Default disseminator that is associated with every object
* in the repository. The Default Disseminator endows the objects with a
* set of basic generic behaviors that enable a simplistic view of the object
* contents (the Item Index) and a list of all disseminations available on
* the object (the Dissemination Index).
* The Bootstrap disseminator is associated with every behavior definition and
* behavior mechanism object. It defines methods to get the special metadata
* datastreams out of them, and some other methods. (NOTE: The Bootstrap
* Disseminator functionality is NOT YET IMPLEMENTED.
*
* @author [email protected]
* @version $Id: DynamicAccessImpl.java 4141 2005-05-18 22:21:15Z eddie $
*/
public class DynamicAccessImpl
{
private Access m_access;
private ServiceMethodDispatcher dispatcher;
private File reposHomeDir = null;
private Hashtable dynamicBDefToMech = null;
public DynamicAccessImpl(Access m_access, File reposHomeDir, Hashtable dynamicBDefToMech)
{
dispatcher = new ServiceMethodDispatcher();
this.m_access = m_access;
this.reposHomeDir = reposHomeDir;
this.dynamicBDefToMech = dynamicBDefToMech;
}
/**
* Get a list of behavior definition identifiers for dynamic disseminators
* associated with the digital object.
* @param context
* @param PID identifier of digital object being reflected upon
* @param asOfDateTime
* @return an array of behavior definition PIDs
* @throws ServerException
*/
public String[] getBehaviorDefinitions(Context context, String PID,
Date asOfDateTime) throws ServerException
{
// FIXIT! In FUTURE this method might consult some source that tells
// what behavior definitions are appropriate to dynamically associate
// with the object. The rules for association might be based on the
// context or based on something about the particular object (PID).
// There is one rule that is always true - associate the Default
// behavior definition with EVERY object. For now we will just take the
// dynamic behavior definitions that were loaded by DynamicAccessModule.
// NOTE: AT THIS TIME THERE THERE IS JUST ONE LOADED, NAMELY,
// THE DEFAULT DISSEMINATOR BDEF (bDefPID = fedora-system:3)
ArrayList bdefs = new ArrayList();
Iterator iter = dynamicBDefToMech.keySet().iterator();
while (iter.hasNext())
{
bdefs.add(iter.next());
}
return (String[])bdefs.toArray(new String[0]);
}
/**
* Get the behavior method defintions for a given dynamic disseminator that
* is associated with the digital object. The dynamic disseminator is
* identified by the bDefPID.
* @param context
* @param PID identifier of digital object being reflected upon
* @param bDefPID identifier of dynamic behavior definition
* @param asOfDateTime
* @return an array of method definitions
* @throws ServerException
*/
public MethodDef[] getBehaviorMethods(Context context, String PID,
String bDefPID, Date asOfDateTime) throws ServerException
{
Class mechClass = (Class) dynamicBDefToMech.get(bDefPID);
if (mechClass != null)
{
try
{
Method method = mechClass.getMethod("reflectMethods", (Class[])null);
return (MethodDef[])method.invoke(null, (Object[])null);
}
catch (Exception e)
{
throw new GeneralException("[DynamicAccessImpl] returned error when "
+ "attempting to get dynamic behavior method definitions. "
+ "The underlying error class was: "
+ e.getClass().getName() + ". The message "
+ "was \"" + e.getMessage() + "\"");
}
}
throw new MethodNotFoundException("[DynamicAccessImpl] The object, "
+ PID + " does not have the dynamic behavior definition " + bDefPID);
}
/**
* Get an XML encoding of the behavior defintions for a given dynamic
* disseminator that is associated with the digital object. The dynamic
* disseminator is identified by the bDefPID.
* @param context
* @param PID identifier of digital object being reflected upon
* @param bDefPID identifier of dynamic behavior definition
* @param asOfDateTime
* @return MIME-typed stream containing XML-encoded method definitions
* @throws ServerException
*/
public MIMETypedStream getBehaviorMethodsXML(Context context, String PID,
String bDefPID, Date asOfDateTime) throws ServerException
{
return null;
}
private String getReposBaseURL(String protocol, String port) {
String reposBaseURL = null;
String fedoraServerHost = ((Module)m_access).getServer().getParameter("fedoraServerHost");
reposBaseURL = protocol + "://" + fedoraServerHost + ":" + port;
return reposBaseURL;
}
/**
* Perform a dissemination for a behavior method that belongs to a
* dynamic disseminator that is associate with the digital object. The
* method belongs to the dynamic behavior definition and is implemented
* by a dynamic behavior mechanism (which is an internal service in the
* repository access subsystem).
* @param context
* @param PID identifier of the digital object being disseminated
* @param bDefPID identifier of dynamic behavior definition
* @param methodName
* @param userParms
* @param asOfDateTime
* @return a MIME-typed stream containing the dissemination result
* @throws ServerException
*/
public MIMETypedStream getDissemination(Context context, String PID,
String bDefPID, String methodName, Property[] userParms,
Date asOfDateTime, DOReader reader) throws ServerException
{
if (bDefPID.equalsIgnoreCase("fedora-system:3"))
{
// FIXIT!! Use lookup to dynamicBDefToMech table to get class for
// DefaultDisseminatorImpl and construct via Java reflection.
String reposBaseURL = getReposBaseURL(
context.getEnvironmentValue(Constants.HTTP_REQUEST.SECURITY.uri).equals(Constants.HTTP_REQUEST.SECURE.uri)
? "https" : "http",
context.getEnvironmentValue(Constants.HTTP_REQUEST.SERVER_PORT.uri)
);
Object result = dispatcher.invokeMethod(
new DefaultDisseminatorImpl(context, asOfDateTime, reader, m_access,
reposBaseURL, reposHomeDir), methodName, userParms);
if (result.getClass().getName().equalsIgnoreCase(
"fedora.server.storage.types.MIMETypedStream"))
{
return (MIMETypedStream)result;
}
else
{
throw new GeneralException("[DynamicAccessImpl] returned error. "
+ "Internal service must return a MIME typed stream. "
+ "(see fedora.server.storage.types.MIMETypedStream)");
}
}
else
{
// FIXIT! (FUTURE) Open up the possibility of there being other
// kinds of dynamic behaviors. Use the bDefPID to locate the
// appropriate mechanism for the dynamic behavior. In future
// we want the mechanism for a dynamic behavior def intion to
// be able to be either an internal services, a local services,
// or a distributed service. We'll have to rework some things to
// be able to see what kind of mechanism we have, and to do the
// request dispatching appropriately.
}
return null;
}
/**
* Get the definitions for all dynamic disseminations on the object. This will
* return the method definitions for all methods for all of the dynamic
* disseminators associated with the object.
* @param context
* @param PID identifier of digital object being reflected upon
* @param asOfDateTime
* @return an array of object method definitions
* @throws ServerException
*/
public ObjectMethodsDef[] listMethods(Context context, String PID,
Date asOfDateTime) throws ServerException
{
String[] bDefPIDs = getBehaviorDefinitions(context, PID, asOfDateTime);
Date versDateTime = asOfDateTime;
ArrayList objectMethods = new ArrayList();
for (int i=0; i© 2015 - 2025 Weber Informatics LLC | Privacy Policy