";
private static final String MULTIPART_BYTERANGES_HEADER = "multipart/byteranges; boundary=" + MULTIPART_BYTERANGES_BOUNDRY;
private static final String MULTIPART_BYTERANGES_BOUNDRY_SEP = "--" + MULTIPART_BYTERANGES_BOUNDRY;
private static final String MULTIPART_BYTERANGES_BOUNDRY_END = MULTIPART_BYTERANGES_BOUNDRY_SEP + "--";
private static final String HEADER_CONTENT_TYPE = "Content-Type";
private static final String HEADER_CONTENT_RANGE = "Content-Range";
private static final String HEADER_CONTENT_LENGTH = "Content-Length";
private static final String HEADER_ACCEPT_RANGES = "Accept-Ranges";
private static final String HEADER_RANGE = "Range";
private static final String HEADER_ETAG = "ETag";
private static final String HEADER_CACHE_CONTROL = "Cache-Control";
private static final String HEADER_LAST_MODIFIED = "Last-Modified";
private static final String HEADER_USER_AGENT = "User-Agent";
private static final String HEADER_CONTENT_DISPOSITION = "Content-Disposition";
/** size of a multi-part byte range output buffer */
private static final int CHUNKSIZE = 64*1024;
protected static final String MIMETYPE_OCTET_STREAM = "application/octet-stream";
protected static final String MSG_ERROR_CONTENT_MISSING = "error_content_missing";
protected static final String URL_DIRECT = "d";
protected static final String URL_DIRECT_LONG = "direct";
protected static final String URL_ATTACH = "a";
protected static final String URL_ATTACH_LONG = "attach";
protected static final String ARG_PROPERTY = "property";
protected static final String ARG_PATH = "path";
/**
* Gets the logger to use for this request.
*
* This will show all debug entries from this class as though they
* came from the subclass.
*
* @return The logger
*/
protected abstract Log getLogger();
/**
* Processes the download request using the current context i.e. no
* authentication checks are made, it is presumed they have already
* been done.
*
* @param req The HTTP request
* @param res The HTTP response
* @param redirectToLogin Flag to determine whether to redirect to the login
* page if the user does not have the correct permissions
*/
protected void processDownloadRequest(HttpServletRequest req, HttpServletResponse res,
boolean redirectToLogin, boolean transmitContent)
throws ServletException, IOException
{
Log logger = getLogger();
String uri = req.getRequestURI();
if (logger.isDebugEnabled())
{
String queryString = req.getQueryString();
logger.debug("Processing URL: " + uri +
((queryString != null && queryString.length() > 0) ? ("?" + queryString) : ""));
}
uri = uri.substring(req.getContextPath().length());
StringTokenizer t = new StringTokenizer(uri, "/");
int tokenCount = t.countTokens();
t.nextToken(); // skip servlet name
// attachment mode (either 'attach' or 'direct')
String attachToken = t.nextToken();
boolean attachment = URL_ATTACH.equals(attachToken) || URL_ATTACH_LONG.equals(attachToken);
ServiceRegistry serviceRegistry = getServiceRegistry(getServletContext());
// get or calculate the noderef and filename to download as
NodeRef nodeRef;
String filename;
// do we have a path parameter instead of a NodeRef?
String path = req.getParameter(ARG_PATH);
if (path != null && path.length() != 0)
{
// process the name based path to resolve the NodeRef and the Filename element
PathRefInfo pathInfo = resolveNamePath(getServletContext(), path);
nodeRef = pathInfo.NodeRef;
filename = pathInfo.Filename;
}
else
{
// a NodeRef must have been specified if no path has been found
if (tokenCount < 6)
{
throw new IllegalArgumentException("Download URL did not contain all required args: " + uri);
}
// assume 'workspace' or other NodeRef based protocol for remaining URL elements
StoreRef storeRef = new StoreRef(t.nextToken(), t.nextToken());
String id = URLDecoder.decode(t.nextToken());
// build noderef from the appropriate URL elements
nodeRef = new NodeRef(storeRef, id);
if (tokenCount > 6)
{
// found additional relative path elements i.e. noderefid/images/file.txt
// this allows a url to reference siblings nodes via a cm:name based relative path
// solves the issue with opening HTML content containing relative URLs in HREF or IMG tags etc.
List paths = new ArrayList(tokenCount - 5);
while (t.hasMoreTokens())
{
paths.add(URLDecoder.decode(t.nextToken()));
}
filename = paths.get(paths.size() - 1);
try
{
NodeRef parentRef = serviceRegistry.getNodeService().getPrimaryParent(nodeRef).getParentRef();
FileInfo fileInfo = serviceRegistry.getFileFolderService().resolveNamePath(parentRef, paths);
nodeRef = fileInfo.getNodeRef();
}
catch (FileNotFoundException e)
{
throw new AlfrescoRuntimeException("Unable to find node reference by relative path:" + uri);
}
}
else
{
// filename is last remaining token
filename = t.nextToken();
}
}
// get qualified of the property to get content from - default to ContentModel.PROP_CONTENT
QName propertyQName = ContentModel.PROP_CONTENT;
String property = req.getParameter(ARG_PROPERTY);
if (property != null && property.length() != 0)
{
propertyQName = QName.createQName(property);
}
if (logger.isDebugEnabled())
{
logger.debug("Found NodeRef: " + nodeRef);
logger.debug("Will use filename: " + filename);
logger.debug("For property: " + propertyQName);
logger.debug("With attachment mode: " + attachment);
}
// get the services we need to retrieve the content
NodeService nodeService = serviceRegistry.getNodeService();
ContentService contentService = serviceRegistry.getContentService();
PermissionService permissionService = serviceRegistry.getPermissionService();
try
{
// check that the user has at least READ_CONTENT access - else redirect to the login page
if (permissionService.hasPermission(nodeRef, PermissionService.READ_CONTENT) == AccessStatus.DENIED)
{
if (logger.isDebugEnabled())
logger.debug("User does not have permissions to read content for NodeRef: " + nodeRef.toString());
if (redirectToLogin)
{
if (logger.isDebugEnabled())
logger.debug("Redirecting to login page...");
// TODO: replace with serviceRegistry.getAuthorityService().hasGuestAuthority() from 3.1E
if (!AuthenticationUtil.getFullyAuthenticatedUser().equals(AuthenticationUtil.getGuestUserName()))
{
req.getSession().setAttribute(LoginBean.LOGIN_NOPERMISSIONS, Boolean.TRUE);
}
redirectToLoginPage(req, res, getServletContext());
}
else
{
if (logger.isDebugEnabled())
logger.debug("Returning 403 Forbidden error...");
res.sendError(HttpServletResponse.SC_FORBIDDEN);
}
return;
}
// check If-Modified-Since header and set Last-Modified header as appropriate
Date modified = (Date)nodeService.getProperty(nodeRef, ContentModel.PROP_MODIFIED);
if (modified != null)
{
long modifiedSince = req.getDateHeader(HEADER_IF_MODIFIED_SINCE);
if (modifiedSince > 0L)
{
// round the date to the ignore millisecond value which is not supplied by header
long modDate = (modified.getTime() / 1000L) * 1000L;
if (modDate <= modifiedSince)
{
if (logger.isDebugEnabled())
logger.debug("Returning 304 Not Modified.");
res.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
return;
}
}
res.setDateHeader(HEADER_LAST_MODIFIED, modified.getTime());
res.setHeader(HEADER_CACHE_CONTROL, "must-revalidate");
res.setHeader(HEADER_ETAG, "\"" + Long.toString(modified.getTime()) + "\"");
}
if (attachment == true)
{
// set header based on filename - will force a Save As from the browse if it doesn't recognise it
// this is better than the default response of the browser trying to display the contents
res.setHeader(HEADER_CONTENT_DISPOSITION, "attachment");
}
// get the content reader
ContentReader reader = contentService.getReader(nodeRef, propertyQName);
// ensure that it is safe to use
reader = FileContentReader.getSafeContentReader(
reader,
Application.getMessage(req.getSession(), MSG_ERROR_CONTENT_MISSING),
nodeRef, reader);
String mimetype = reader.getMimetype();
// fall back if unable to resolve mimetype property
if (mimetype == null || mimetype.length() == 0)
{
MimetypeService mimetypeMap = serviceRegistry.getMimetypeService();
mimetype = MIMETYPE_OCTET_STREAM;
int extIndex = filename.lastIndexOf('.');
if (extIndex != -1)
{
String ext = filename.substring(extIndex + 1);
mimetype = mimetypeMap.getMimetype(ext);
}
}
// explicitly set the content disposition header if the content is powerpoint
if (!attachment && (mimetype.equals(POWER_POINT_2007_DOCUMENT_MIMETYPE) ||
mimetype.equals(POWER_POINT_DOCUMENT_MIMETYPE)))
{
res.setHeader(HEADER_CONTENT_DISPOSITION, "attachment");
}
// get the content and stream directly to the response output stream
// assuming the repo is capable of streaming in chunks, this should allow large files
// to be streamed directly to the browser response stream.
res.setHeader(HEADER_ACCEPT_RANGES, "bytes");
// for a GET request, transmit the content else just the headers are sent
if (transmitContent)
{
try
{
boolean processedRange = false;
String range = req.getHeader(HEADER_CONTENT_RANGE);
if (range == null)
{
range = req.getHeader(HEADER_RANGE);
}
if (range != null)
{
if (logger.isDebugEnabled())
logger.debug("Found content range header: " + range);
// ensure the range header is starts with "bytes=" and process the range(s)
if (range.length() > 6)
{
processedRange = processRange(
res, reader, range.substring(6), nodeRef, propertyQName,
mimetype, req.getHeader(HEADER_USER_AGENT));
}
}
if (processedRange == false)
{
if (logger.isDebugEnabled())
logger.debug("Sending complete file content...");
// set mimetype for the content and the character encoding for the stream
res.setContentType(mimetype);
res.setCharacterEncoding(reader.getEncoding());
// return the complete entity range
long size = reader.getSize();
res.setHeader(HEADER_CONTENT_RANGE, "bytes 0-" + Long.toString(size-1L) + "/" + Long.toString(size));
res.setHeader(HEADER_CONTENT_LENGTH, Long.toString(size));
reader.getContent( res.getOutputStream() );
}
}
catch (SocketException e1)
{
// the client cut the connection - our mission was accomplished apart from a little error message
if (logger.isDebugEnabled())
logger.debug("Client aborted stream read:\n\tnode: " + nodeRef + "\n\tcontent: " + reader);
}
catch (ContentIOException e2)
{
if (logger.isInfoEnabled())
logger.info("Failed stream read:\n\tnode: " + nodeRef + " due to: " + e2.getMessage());
}
catch (Throwable err)
{
if (err.getCause() instanceof SocketException)
{
// the client cut the connection - our mission was accomplished apart from a little error message
if (logger.isDebugEnabled())
logger.debug("Client aborted stream read:\n\tnode: " + nodeRef + "\n\tcontent: " + reader);
}
else throw err;
}
}
else
{
if (logger.isDebugEnabled())
logger.debug("HEAD request processed - no content sent.");
res.getOutputStream().close();
}
}
catch (Throwable err)
{
throw new AlfrescoRuntimeException("Error during download content servlet processing: " + err.getMessage(), err);
}
}
/**
* Process a range header - handles single and multiple range requests.
*/
private boolean processRange(HttpServletResponse res, ContentReader reader, String range,
NodeRef ref, QName property, String mimetype, String userAgent)
throws IOException
{
// test for multiple byte ranges present in header
if (range.indexOf(',') == -1)
{
return processSingleRange(res, reader, range, mimetype);
}
else
{
return processMultiRange(res, range, ref, property, mimetype, userAgent);
}
}
/**
* Process a single range request.
*
* @param res HttpServletResponse
* @param reader ContentReader to retrieve content
* @param range Range header value
* @param mimetype Content mimetype
*
* @return true if processed range, false otherwise
*/
private boolean processSingleRange(HttpServletResponse res, ContentReader reader, String range, String mimetype)
throws IOException
{
// return the specific set of bytes as requested in the content-range header
/* Examples of byte-content-range-spec values, assuming that the entity contains total of 1234 bytes:
The first 500 bytes:
bytes 0-499/1234
The second 500 bytes:
bytes 500-999/1234
All except for the first 500 bytes:
bytes 500-1233/1234 */
/* 'Range' header example:
bytes=10485760-20971519 */
boolean processedRange = false;
Range r = null;
try
{
r = Range.constructRange(range, mimetype, reader.getSize());
}
catch (IllegalArgumentException err)
{
if (getLogger().isDebugEnabled())
getLogger().debug("Failed to parse range header - returning 416 status code: " + err.getMessage());
res.setStatus(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);
res.setHeader(HEADER_CONTENT_RANGE, "\"*\"");
res.getOutputStream().close();
return true;
}
// set Partial Content status and range headers
res.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);
res.setContentType(mimetype);
String contentRange = "bytes " + Long.toString(r.start) + "-" + Long.toString(r.end) + "/" + Long.toString(reader.getSize());
res.setHeader(HEADER_CONTENT_RANGE, contentRange);
res.setHeader(HEADER_CONTENT_LENGTH, Long.toString((r.end - r.start) + 1L));
if (getLogger().isDebugEnabled())
getLogger().debug("Processing: Content-Range: " + contentRange);
InputStream is = null;
try
{
// output the binary data for the range
ServletOutputStream os = res.getOutputStream();
is = reader.getContentInputStream();
streamRangeBytes(r, is, os, 0L);
os.close();
processedRange = true;
}
catch (IOException err)
{
if (getLogger().isDebugEnabled())
getLogger().debug("Unable to process single range due to IO Exception: " + err.getMessage());
throw err;
}
finally
{
if (is != null) is.close();
}
return processedRange;
}
/**
* Process multiple ranges.
*
* @param res HttpServletResponse
* @param range Range header value
* @param ref NodeRef to the content for streaming
* @param property Content Property for the content
* @param mimetype Mimetype of the content
* @param userAgent User Agent of the caller
*
* @return true if processed range, false otherwise
*/
private boolean processMultiRange(
HttpServletResponse res, String range, NodeRef ref, QName property, String mimetype, String userAgent)
throws IOException
{
final Log logger = getLogger();
final boolean trace = logger.isTraceEnabled();
// return the sets of bytes as requested in the content-range header
// the response will be formatted as multipart/byteranges media type message
/* Examples of byte-ranges-specifier values (assuming an entity-body of length 10000):
- The first 500 bytes (byte offsets 0-499, inclusive): bytes=0-499
- The second 500 bytes (byte offsets 500-999, inclusive):
bytes=500-999
- The final 500 bytes (byte offsets 9500-9999, inclusive):
bytes=-500
- Or bytes=9500-
- The first and last bytes only (bytes 0 and 9999): bytes=0-0,-1
- Several legal but not canonical specifications of byte offsets 500-999, inclusive:
bytes=500-600,601-999
bytes=500-700,601-999 */
boolean processedRange = false;
// get the content reader
ContentService contentService = getServiceRegistry(getServletContext()).getContentService();
ContentReader reader = contentService.getReader(ref, property);
final List ranges = new ArrayList(8);
long entityLength = reader.getSize();
for (StringTokenizer t=new StringTokenizer(range, ", "); t.hasMoreTokens(); /**/)
{
try
{
ranges.add(Range.constructRange(t.nextToken(), mimetype, entityLength));
}
catch (IllegalArgumentException err)
{
if (getLogger().isDebugEnabled())
getLogger().debug("Failed to parse range header - returning 416 status code: " + err.getMessage());
res.setStatus(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);
res.setHeader(HEADER_CONTENT_RANGE, "\"*\"");
res.getOutputStream().close();
return true;
}
}
if (ranges.size() != 0)
{
// merge byte ranges if possible - IE handles this well, FireFox not so much
if (userAgent == null || userAgent.indexOf("MSIE ") != -1)
{
Collections.sort(ranges);
for (int i=0; i= second.start)
{
if (logger.isDebugEnabled())
logger.debug("Merging byte range: " + first + " with " + second);
if (first.end < second.end)
{
// merge second range into first
first.end = second.end;
}
// else we simply discard the second range - it is contained within the first
// delete second range
ranges.remove(i + 1);
// reset loop index
i--;
}
}
}
// calculate response content length
long length = MULTIPART_BYTERANGES_BOUNDRY_END.length() + 2;
for (Range r : ranges)
{
length += r.getLength();
}
// output headers as we have at least one range to process
res.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);
res.setHeader(HEADER_CONTENT_TYPE, MULTIPART_BYTERANGES_HEADER);
res.setHeader(HEADER_CONTENT_LENGTH, Long.toString(length));
ServletOutputStream os = res.getOutputStream();
InputStream is = null;
try
{
for (Range r : ranges)
{
if (logger.isDebugEnabled())
logger.debug("Processing: " + r.getContentRange());
try
{
// output the header bytes for the range
r.outputHeader(os);
// output the binary data for the range
// need a new reader for each new InputStream
is = contentService.getReader(ref, property).getContentInputStream();
streamRangeBytes(r, is, os, 0L);
is.close();
is = null;
// section marker and flush stream
os.println();
os.flush();
}
catch (IOException err)
{
if (getLogger().isDebugEnabled())
getLogger().debug("Unable to process multiple range due to IO Exception: " + err.getMessage());
throw err;
}
}
}
finally
{
if (is != null)
{
is.close();
}
}
// end marker
os.println(MULTIPART_BYTERANGES_BOUNDRY_END);
os.close();
processedRange = true;
}
return processedRange;
}
/**
* Stream a range of bytes from the given InputStream to the ServletOutputStream
*
* @param r Byte Range to process
* @param is InputStream
* @param os ServletOutputStream
* @param offset Assumed InputStream position - to calculate skip bytes from
*
* @return current InputStream position - so the stream can be reused if required
*/
private void streamRangeBytes(final Range r, final InputStream is, final ServletOutputStream os, long offset)
throws IOException
{
final Log logger = getLogger();
final boolean trace = logger.isTraceEnabled();
// TODO: investigate using getFileChannel() on ContentReader
if (r.start != 0L)
{
long skipped = offset;
while (skipped < r.start)
{
skipped += is.skip(r.start - skipped);
}
}
long span = (r.end - r.start) + 1L;
long bytesLeft = span;
int read = 0;
byte[] buf = new byte[((int)bytesLeft) < CHUNKSIZE ? (int)bytesLeft : CHUNKSIZE];
while ((read = is.read(buf)) > 0 && bytesLeft != 0L)
{
os.write(buf, 0, read);
bytesLeft -= (long)read;
if (bytesLeft != 0L)
{
int resize = ((int)bytesLeft) < CHUNKSIZE ? (int)bytesLeft : CHUNKSIZE;
if (resize != buf.length)
{
buf = new byte[resize];
}
}
if (trace) logger.trace("...wrote " + read + " bytes, with " + bytesLeft + " to go...");
}
}
/**
* Representation of a single byte range.
*/
private static class Range implements Comparable
{
private long start;
private long end;
private long entityLength;
private String contentType;
private String contentRange;
/**
* Constructor
*
* @param contentType Mimetype of the range content
* @param start Start position in the parent entity
* @param end End position in the parent entity
* @param entityLength Length of the parent entity
*/
Range(String contentType, long start, long end, long entityLength)
{
this.contentType = HEADER_CONTENT_TYPE + ": " + contentType;
this.start = start;
this.end = end;
this.entityLength = entityLength;
}
/**
* Factory method to construct a byte range from a range header value.
*
* @param range Range header value
* @param contentType Mimetype of the range
* @param entityLength Length of the parent entity
*
* @return Range
*
* @throws IllegalArgumentException for an invalid range
*/
static Range constructRange(String range, String contentType, long entityLength)
{
if (range == null)
{
throw new IllegalArgumentException("Range argument is mandatory");
}
// strip total if present - it does not give us anything useful
if (range.indexOf('/') != -1)
{
range = range.substring(0, range.indexOf('/'));
}
// find the separator
int separator = range.indexOf('-');
if (separator == -1)
{
throw new IllegalArgumentException("Invalid range: " + range);
}
try
{
// split range and parse values
long start = 0L;
if (separator != 0)
{
start = Long.parseLong(range.substring(0, separator));
}
long end = entityLength - 1L;
if (separator != range.length() - 1)
{
end = Long.parseLong(range.substring(separator + 1));
}
// return object to represent the byte-range
return new Range(contentType, start, end, entityLength);
}
catch (NumberFormatException err)
{
throw new IllegalArgumentException("Unable to parse range value: " + range);
}
}
/**
* Output the header bytes for a multi-part byte range header
*/
void outputHeader(ServletOutputStream os) throws IOException
{
// output multi-part boundry separator
os.println(MULTIPART_BYTERANGES_BOUNDRY_SEP);
// output content type and range size sub-header for this part
os.println(this.contentType);
os.println(getContentRange());
os.println();
}
/**
* @return the length in bytes of the byte range content including the header bytes
*/
int getLength()
{
// length in bytes of range plus it's header plus section marker and line feed bytes
return MULTIPART_BYTERANGES_BOUNDRY_SEP.length() + 2 +
this.contentType.length() + 2 +
getContentRange().length() + 4 + (int)(this.end - this.start + 1L) + 2;
}
/**
* @return the Content-Range header string value for this byte range
*/
private String getContentRange()
{
if (this.contentRange == null)
{
this.contentRange = "Content-Range: bytes " + Long.toString(this.start) + "-" +
Long.toString(this.end) + "/" + Long.toString(this.entityLength);
}
return this.contentRange;
}
@Override
public String toString()
{
return this.start + "-" + this.end;
}
/**
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
public int compareTo(Range o)
{
return this.start > o.start ? 1 : -1;
}
}
/**
* Helper to generate a URL to a content node for downloading content from the server.
*
* @param pattern The pattern to use for the URL
* @param ref NodeRef of the content node to generate URL for (cannot be null)
* @param name File name to return in the URL (cannot be null)
*
* @return URL to download the content from the specified node
*/
protected final static String generateUrl(String pattern, NodeRef ref, String name)
{
return MessageFormat.format(pattern, new Object[] {
ref.getStoreRef().getProtocol(),
ref.getStoreRef().getIdentifier(),
ref.getId(),
URLEncoder.encode(name) } );
}
}