/*
* BitsreamReader.java
*
* Version: $Revision: 4465 $
*
* Date: $Date: 2009-10-24 02:46:21 +0000 (Sat, 24 Oct 2009) $
*
* Copyright (c) 2002, Hewlett-Packard Company and Massachusetts
* Institute of Technology. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the Hewlett-Packard Company nor the name of the
* Massachusetts Institute of Technology nor the names of their
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.dspace.app.xmlui.cocoon;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.sql.SQLException;
import java.util.Map;
import javax.mail.internet.MimeUtility;
import javax.servlet.http.HttpServletResponse;
import org.apache.avalon.excalibur.pool.Recyclable;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.ResourceNotFoundException;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.Response;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.environment.http.HttpEnvironment;
import org.apache.cocoon.environment.http.HttpResponse;
import org.apache.cocoon.reading.AbstractReader;
import org.apache.cocoon.util.ByteRange;
import org.dspace.app.xmlui.utils.AuthenticationUtil;
import org.dspace.app.xmlui.utils.ContextUtil;
import org.dspace.authorize.AuthorizeException;
import org.dspace.authorize.AuthorizeManager;
import org.dspace.authorize.ResourcePolicy;
import org.dspace.content.Bitstream;
import org.dspace.content.Bundle;
import org.dspace.content.DSpaceObject;
import org.dspace.content.Item;
import org.dspace.core.ConfigurationManager;
import org.dspace.core.Constants;
import org.dspace.core.Context;
import org.dspace.handle.HandleManager;
import org.dspace.usage.UsageEvent;
import org.dspace.utils.DSpace;
import org.xml.sax.SAXException;
import org.apache.log4j.Logger;
import org.dspace.core.LogManager;
/**
* The BitstreamReader will query DSpace for a particular bitstream and transmit
* it to the user. There are several method of specifing the bitstream to be
* develivered. You may refrence a bitstream by either it's id or attempt to
* resolve the bitstream's name.
*
* /bitstream/{handle}/{sequence}/{name}
*
* <map:read type="BitstreamReader">
* <map:parameter name="handle" value="{1}/{2}"/>
* <map:parameter name="sequence" value="{3}"/>
* <map:parameter name="name" value="{4}"/>
* </map:read>
*
* When no handle is assigned yet you can access a bistream
* using it's internal ID.
*
* /bitstream/id/{bitstreamID}/{sequence}/{name}
*
* <map:read type="BitstreamReader">
* <map:parameter name="bitstreamID" value="{1}"/>
* <map:parameter name="sequence" value="{2}"/>
* </map:read>
*
* Alternativly, you can access the bitstream via a name instead
* of directly through it's sequence.
*
* /html/{handle}/{name}
*
* <map:read type="BitstreamReader">
* <map:parameter name="handle" value="{1}/{2}"/>
* <map:parameter name="name" value="{3}"/>
* </map:read>
*
* Again when no handle is available you can also access it
* via an internal itemID & name.
*
* /html/id/{itemID}/{name}
*
* <map:read type="BitstreamReader">
* <map:parameter name="itemID" value="{1}"/>
* <map:parameter name="name" value="{2}"/>
* </map:read>
*
* @author Scott Phillips
*/
public class BitstreamReader extends AbstractReader implements Recyclable
{
private static Logger log = Logger.getLogger(BitstreamReader.class);
/**
* Messages to be sent when the user is not authorized to view
* a particular bitstream. They will be redirected to the login
* where this message will be displayed.
*/
private final static String AUTH_REQUIRED_HEADER = "xmlui.BitstreamReader.auth_header";
private final static String AUTH_REQUIRED_MESSAGE = "xmlui.BitstreamReader.auth_message";
/**
* How big of a buffer should we use when reading from the bitstream before
* writting to the HTTP response?
*/
protected static final int BUFFER_SIZE = 8192;
/**
* When should a bitstream expire in milliseconds. This should be set to
* some low value just to prevent someone hiting DSpace repeatily from
* killing the server. Note: 1000 milliseconds are in a second.
*
* Format: minutes * seconds * milliseconds
* 60 * 60 * 1000 == 1 hour
*/
protected static final int expires = 60 * 60 * 1000;
/** The Cocoon response */
protected Response response;
/** The Cocoon request */
protected Request request;
/** The bitstream file */
protected InputStream bitstreamInputStream;
/** The bitstream's reported size */
protected long bitstreamSize;
/** The bitstream's mime-type */
protected String bitstreamMimeType;
/** The bitstream's name */
protected String bitstreamName;
/** True if bitstream is readable by anonymous users */
protected boolean isAnonymouslyReadable;
/** Item containing the Bitstream */
private Item item = null;
/** True if user agent making this request was identified as spider. */
private boolean isSpider = false;
/**
* Set up the bitstream reader.
*
* See the class description for information on configuration options.
*/
public void setup(SourceResolver resolver, Map objectModel, String src,
Parameters par) throws ProcessingException, SAXException,
IOException
{
super.setup(resolver, objectModel, src, par);
try
{
this.request = ObjectModelHelper.getRequest(objectModel);
this.response = ObjectModelHelper.getResponse(objectModel);
Context context = ContextUtil.obtainContext(objectModel);
// Get our parameters that identify the bitstream
int itemID = par.getParameterAsInteger("itemID", -1);
int bitstreamID = par.getParameterAsInteger("bitstreamID", -1);
String handle = par.getParameter("handle", null);
int sequence = par.getParameterAsInteger("sequence", -1);
String name = par.getParameter("name", null);
this.isSpider = par.getParameter("userAgent", "").equals("spider");
// Reslove the bitstream
Bitstream bitstream = null;
DSpaceObject dso = null;
if (bitstreamID > -1)
{
// Direct refrence to the individual bitstream ID.
bitstream = Bitstream.find(context, bitstreamID);
}
else if (itemID > -1)
{
// Referenced by internal itemID
item = Item.find(context, itemID);
if (sequence > -1)
{
bitstream = findBitstreamBySequence(item, sequence);
}
else if (name != null)
{
bitstream = findBitstreamByName(item, name);
}
}
else if (handle != null)
{
// Reference by an item's handle.
dso = HandleManager.resolveToObject(context,handle);
if (dso instanceof Item)
{
item = (Item)dso;
if (sequence > -1)
{
bitstream = findBitstreamBySequence(item,sequence);
}
else if (name != null)
{
bitstream = findBitstreamByName(item,name);
}
}
}
//if initial search was by sequence number and found nothing,
//then try to find bitstream by name (assuming we have a file name)
if((sequence > -1 && bitstream==null) && name!=null)
{
bitstream = findBitstreamByName(item,name);
//if we found bitstream by name, send a redirect to its new sequence number location
if(bitstream!=null)
{
String redirectURL = "";
//build redirect URL based on whether item has a handle assigned yet
if(item.getHandle()!=null && item.getHandle().length()>0)
redirectURL = request.getContextPath() + "/bitstream/handle/" + item.getHandle();
else
redirectURL = request.getContextPath() + "/bitstream/item/" + item.getID();
redirectURL += "/" + name + "?sequence=" + bitstream.getSequenceID();
HttpServletResponse httpResponse = (HttpServletResponse)
objectModel.get(HttpEnvironment.HTTP_RESPONSE_OBJECT);
httpResponse.sendRedirect(redirectURL);
return;
}
}
// Was a bitstream found?
if (bitstream == null)
{
throw new ResourceNotFoundException("Unable to locate bitstream");
}
// Is there a User logged in and does the user have access to read it?
boolean isAuthorized = AuthorizeManager.authorizeActionBoolean(context, bitstream, Constants.READ);
if (item != null && item.isWithdrawn() && !AuthorizeManager.isAdmin(context))
{
isAuthorized = false;
log.info(LogManager.getHeader(context, "view_bitstream", "handle=" + item.getHandle() + ",withdrawn=true"));
}
if (!isAuthorized)
{
if(context.getCurrentUser() != null){
// A user is logged in, but they are not authorized to read this bitstream,
// instead of asking them to login again we'll point them to a friendly error
// message that tells them the bitstream is restricted.
String redictURL = request.getContextPath() + "/handle/";
if (item!=null){
redictURL += item.getHandle();
}
else if(dso!=null){
redictURL += dso.getHandle();
}
redictURL += "/restricted-resource?bitstreamId=" + bitstream.getID();
HttpServletResponse httpResponse = (HttpServletResponse)
objectModel.get(HttpEnvironment.HTTP_RESPONSE_OBJECT);
httpResponse.sendRedirect(redictURL);
return;
}
else{
// The user does not have read access to this bitstream. Inturrupt this current request
// and then forward them to the login page so that they can be authenticated. Once that is
// successfull they will request will be resumed.
AuthenticationUtil.interruptRequest(objectModel, AUTH_REQUIRED_HEADER, AUTH_REQUIRED_MESSAGE, null);
// Redirect
String redictURL = request.getContextPath() + "/login";
HttpServletResponse httpResponse = (HttpServletResponse)
objectModel.get(HttpEnvironment.HTTP_RESPONSE_OBJECT);
httpResponse.sendRedirect(redictURL);
return;
}
}
// Success, bitstream found and the user has access to read it.
// Store these for later retreval:
this.bitstreamInputStream = bitstream.retrieve();
this.bitstreamSize = bitstream.getSize();
this.bitstreamMimeType = bitstream.getFormat().getMIMEType();
this.bitstreamName = bitstream.getName();
if (context.getCurrentUser() == null)
{
this.isAnonymouslyReadable = true;
}
else
{
this.isAnonymouslyReadable = false;
for (ResourcePolicy rp : AuthorizeManager.getPoliciesActionFilter(context, bitstream, Constants.READ))
{
if (rp.getGroupID() == 0)
this.isAnonymouslyReadable = true;
}
}
// Trim any path information from the bitstream
if (bitstreamName != null && bitstreamName.length() >0 )
{
int finalSlashIndex = bitstreamName.lastIndexOf("/");
if (finalSlashIndex > 0)
{
bitstreamName = bitstreamName.substring(finalSlashIndex+1);
}
}
else
{
// In-case there is no bitstream name...
bitstreamName = "bitstream";
}
// Log that the bitstream has been viewed, this is none-cached and the complexity
// of adding it to the sitemap for every possible bitstre uri is not very tractable
new DSpace().getEventService().fireEvent(
new UsageEvent(
UsageEvent.Action.VIEW,
ObjectModelHelper.getRequest(objectModel),
ContextUtil.obtainContext(ObjectModelHelper.getRequest(objectModel)),
bitstream));
}
catch (SQLException sqle)
{
throw new ProcessingException("Unable to read bitstream.",sqle);
}
catch (AuthorizeException ae)
{
throw new ProcessingException("Unable to read bitstream.",ae);
}
}
/**
* Find the bitstream identified by a sequence number on this item.
*
* @param item A DSpace item
* @param sequence The sequence of the bitstream
* @return The bitstream or null if none found.
*/
private Bitstream findBitstreamBySequence(Item item, int sequence) throws SQLException
{
if (item == null)
return null;
Bundle[] bundles = item.getBundles();
for (Bundle bundle : bundles)
{
Bitstream[] bitstreams = bundle.getBitstreams();
for (Bitstream bitstream : bitstreams)
{
if (bitstream.getSequenceID() == sequence)
{
return bitstream;
}
}
}
return null;
}
/**
* Return the bitstream from the given item that is identified by the
* given name. If the name has prepended directories they will be removed
* one at a time until a bitstream is found. Note that if two bitstreams
* have the same name then the first bitstream will be returned.
*
* @param item A DSpace item
* @param name The name of the bitstream
* @return The bitstream or null if none found.
*/
private Bitstream findBitstreamByName(Item item, String name) throws SQLException
{
if (name == null || item == null)
return null;
// Determine our the maximum number of directories that will be removed for a path.
int maxDepthPathSearch = 3;
if (ConfigurationManager.getProperty("xmlui.html.max-depth-guess") != null)
maxDepthPathSearch = ConfigurationManager.getIntProperty("xmlui.html.max-depth-guess");
// Search for the named bitstream on this item. Each time through the loop
// a directory is removed from the name until either our maximum depth is
// reached or the bitstream is found. Note: an extra pass is added on to the
// loop for a last ditch effort where all directory paths will be removed.
for (int i = 0; i < maxDepthPathSearch+1; i++)
{
// Search through all the bitstreams and see
// if the name can be found
Bundle[] bundles = item.getBundles();
for (Bundle bundle : bundles)
{
Bitstream[] bitstreams = bundle.getBitstreams();
for (Bitstream bitstream : bitstreams)
{
if (name.equals(bitstream.getName()))
{
return bitstream;
}
}
}
// The bitstream was not found, so try removing a directory
// off of the name and see if we lost some path information.
int indexOfSlash = name.indexOf('/');
if (indexOfSlash < 0)
// No more directories to remove from the path, so return null for no
// bitstream found.
return null;
name = name.substring(indexOfSlash+1);
// If this is our next to last time through the loop then
// trim everything and only use the trailing filename.
if (i == maxDepthPathSearch-1)
{
int indexOfLastSlash = name.lastIndexOf('/');
if (indexOfLastSlash > -1)
name = name.substring(indexOfLastSlash+1);
}
}
// The named bitstream was not found and we exausted our the maximum path depth that
// we search.
return null;
}
/**
* Write the actual data out to the response.
*
* Some implementation notes,
*
* 1) We set a short expires time just in the hopes of preventing someone
* from overloading the server by clicking reload a bunch of times. I
* realize that this is nowhere near 100% effective but it may help in some
* cases and shouldn't hurt anything.
*
* 2) We accept partial downloads, thus if you lose a connection half way
* through most web browser will enable you to resume downloading the
* bitstream.
*/
public void generate() throws IOException, SAXException,
ProcessingException
{
if (this.bitstreamInputStream == null)
return;
// Only allow If-Modified-Since protocol if request is from a spider
// since response headers would encourage a browser to cache results
// that might change with different authentication..
if (isSpider)
{
// Check for if-modified-since header -- ONLY if not authenticated
long modSince = request.getDateHeader("If-Modified-Since");
if (modSince != -1 && item != null && item.getLastModified().getTime() < modSince)
{
// Item has not been modified since requested date,
// hence bitstream has not; return 304
response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
return;
}
}
// Only set Last-Modified: header for spiders or anonymous
// access, since it might encourage browse to cache the result
// which might leave a result only available to authenticated
// users in the cache for a response later to anonymous user.
try
{
if (item != null && (isSpider || ContextUtil.obtainContext(request).getCurrentUser() == null))
{
// TODO: Currently just borrow the date of the item, since
// we don't have last-mod dates for Bitstreams
response.setDateHeader("Last-Modified", item.getLastModified()
.getTime());
}
}
catch (SQLException e)
{
throw new ProcessingException(e);
}
byte[] buffer = new byte[BUFFER_SIZE];
int length = -1;
// Only encourage caching if this is not a restricted resource, i.e.
// if it is accessed anonymously or is readable by Anonymous:
if (isAnonymouslyReadable)
response.setDateHeader("Expires", System.currentTimeMillis()
+ expires);
// If this is a large bitstream then tell the browser it should treat it as a download.
int threshold = ConfigurationManager.getIntProperty("xmlui.content_disposition_threshold");
if (bitstreamSize > threshold && threshold != 0)
{
String name = bitstreamName;
// Try and make the download file name formated for each browser.
try {
String agent = request.getHeader("USER-AGENT");
if (agent != null && agent.contains("MSIE"))
name = URLEncoder.encode(name,"UTF8");
else if (agent != null && agent.contains("Mozilla"))
name = MimeUtility.encodeText(name, "UTF8", "B");
}
catch (UnsupportedEncodingException see)
{
// do nothing
}
response.setHeader("Content-Disposition", "attachment;filename=" + name);
}
// Turn off partial downloads, they cause problems
// and are only rarely used. Specifically some windows pdf
// viewers are incapable of handling this request. By
// uncommenting the following two lines you will turn this feature back on.
// response.setHeader("Accept-Ranges", "bytes");
// String ranges = request.getHeader("Range");
String ranges = null;
ByteRange byteRange = null;
if (ranges != null)
{
try
{
ranges = ranges.substring(ranges.indexOf('=') + 1);
byteRange = new ByteRange(ranges);
}
catch (NumberFormatException e)
{
byteRange = null;
if (response instanceof HttpResponse)
{
// Respond with status 416 (Request range not
// satisfiable)
((HttpResponse) response).setStatus(416);
}
}
}
if (byteRange != null)
{
String entityLength;
String entityRange;
if (this.bitstreamSize != -1)
{
entityLength = "" + this.bitstreamSize;
entityRange = byteRange.intersection(
new ByteRange(0, this.bitstreamSize)).toString();
}
else
{
entityLength = "*";
entityRange = byteRange.toString();
}
response.setHeader("Content-Range", entityRange + "/"
+ entityLength);
if (response instanceof HttpResponse)
{
// Response with status 206 (Partial content)
((HttpResponse) response).setStatus(206);
}
int pos = 0;
int posEnd;
while ((length = this.bitstreamInputStream.read(buffer)) > -1)
{
posEnd = pos + length - 1;
ByteRange intersection = byteRange
.intersection(new ByteRange(pos, posEnd));
if (intersection != null)
{
out.write(buffer, (int) intersection.getStart()
- pos, (int) intersection.length());
}
pos += length;
}
}
else
{
response.setHeader("Content-Length", String
.valueOf(this.bitstreamSize));
while ((length = this.bitstreamInputStream.read(buffer)) > -1)
{
out.write(buffer, 0, length);
}
out.flush();
}
}
/**
* Returns the mime-type of the bitstream.
*/
public String getMimeType()
{
return this.bitstreamMimeType;
}
/**
* Recycle
*/
public void recycle() {
this.response = null;
this.request = null;
this.bitstreamInputStream = null;
this.bitstreamSize = 0;
this.bitstreamMimeType = null;
}
}