/**
* Store the requested attachment on the filesystem and return a {@code file://} URL where FOP can
* access that file.
*
* @param wiki the name of the owner document's wiki
* @param space the name of the owner document's space
* @param name the name of the owner document
* @param filename the name of the attachment
* @param revision an optional attachment version
* @param context the current request context
* @return a {@code file://} URL where the attachment has been stored
* @throws Exception if the attachment can't be retrieved from the database and stored on the
* filesystem
*/
private URL getURL(
String wiki,
String space,
String name,
String filename,
String revision,
XWikiContext context)
throws Exception {
Map<String, File> usedFiles = getFileMapping(context);
String key = getAttachmentKey(space, name, filename, revision);
if (!usedFiles.containsKey(key)) {
File file = getTemporaryFile(key, context);
XWikiDocument doc =
context
.getWiki()
.getDocument(
new DocumentReference(
StringUtils.defaultString(wiki, context.getDatabase()), space, name),
context);
XWikiAttachment attachment = doc.getAttachment(filename);
if (StringUtils.isNotEmpty(revision)) {
attachment = attachment.getAttachmentRevision(revision, context);
}
FileOutputStream fos = new FileOutputStream(file);
IOUtils.copy(attachment.getContentInputStream(context), fos);
fos.close();
usedFiles.put(key, file);
}
return usedFiles.get(key).toURI().toURL();
}
/**
* Send the attachment content in the response.
*
* @param attachment the attachment to get content from
* @param request the current client request
* @param response the response to write to.
* @param filename the filename to show in the message in case an exception needs to be thrown
* @param context the XWikiContext just in case it is needed to load the attachment content
* @throws XWikiException if something goes wrong
*/
private static void sendContent(
final XWikiAttachment attachment,
final XWikiRequest request,
final XWikiResponse response,
final String filename,
final XWikiContext context)
throws XWikiException {
InputStream stream = null;
try {
setCommonHeaders(attachment, request, response, context);
response.setContentLength(attachment.getContentSize(context));
stream = attachment.getContentInputStream(context);
IOUtils.copy(stream, response.getOutputStream());
} catch (IOException e) {
throw new XWikiException(
XWikiException.MODULE_XWIKI_APP,
XWikiException.ERROR_XWIKI_APP_SEND_RESPONSE_EXCEPTION,
"Exception while sending response",
e);
} finally {
if (stream != null) {
IOUtils.closeQuietly(stream);
}
}
}
/**
* Write a byte range from the attachment to the response, if the requested range is valid and
* falls within the file limits.
*
* @param attachment the attachment to get content from
* @param start the first byte to write
* @param end the last byte to write
* @param request the current client request
* @param response the response to write to.
* @param context the current request context
* @throws XWikiException if the attachment content cannot be retrieved
* @throws IOException if the response cannot be written
*/
private static void writeByteRange(
final XWikiAttachment attachment,
Long start,
Long end,
final XWikiRequest request,
final XWikiResponse response,
final XWikiContext context)
throws XWikiException, IOException {
if (start >= 0 && start < attachment.getContentSize(context)) {
InputStream data = attachment.getContentInputStream(context);
data = new BoundedInputStream(data, end + 1);
data.skip(start);
setCommonHeaders(attachment, request, response, context);
response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);
if ((end - start + 1L) < Integer.MAX_VALUE) {
response.setContentLength((int) (end - start + 1));
}
response.setHeader(
"Content-Range",
"bytes " + start + "-" + end + SEPARATOR + attachment.getContentSize(context));
IOUtils.copyLarge(data, response.getOutputStream());
} else {
response.setStatus(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);
}
}
public void addToCache(String key, XWikiAttachment attachment) throws XWikiException {
if (getImageCache() != null) {
try {
getImageCache()
.set(key, IOUtils.toByteArray(attachment.getContentInputStream(getContext())));
} catch (IOException exp) {
LOGGER.error("Failed to cache image [" + key + "].", exp);
}
} else {
LOGGER.info("Caching of images deactivated.");
}
}
/**
* Reduces the size (i.e. the number of bytes) of an image by scaling its width and height and by
* reducing its compression quality. This helps decreasing the time needed to download the image
* attachment.
*
* @param attachment the image to be shrunk
* @param requestedWidth the desired image width; this value is taken into account only if it is
* greater than zero and less than the current image width
* @param requestedHeight the desired image height; this value is taken into account only if it is
* greater than zero and less than the current image height
* @param keepAspectRatio {@code true} to preserve the image aspect ratio even when both requested
* dimensions are properly specified (in this case the image will be resized to best fit the
* rectangle with the requested width and height), {@code false} otherwise
* @param requestedQuality the desired compression quality
* @param context the XWiki context
* @return the modified image attachment
* @throws Exception if shrinking the image fails
*/
private XWikiAttachment shrinkImage(
XWikiAttachment attachment,
int requestedWidth,
int requestedHeight,
boolean keepAspectRatio,
float requestedQuality,
XWikiContext context)
throws Exception {
Image image = this.imageProcessor.readImage(attachment.getContentInputStream(context));
// Compute the new image dimension.
int currentWidth = image.getWidth(null);
int currentHeight = image.getHeight(null);
int[] dimensions =
reduceImageDimensions(
currentWidth, currentHeight, requestedWidth, requestedHeight, keepAspectRatio);
float quality = requestedQuality;
if (quality < 0) {
// If no scaling is needed and the quality parameter is not specified, return the original
// image.
if (dimensions[0] == currentWidth && dimensions[1] == currentHeight) {
return attachment;
}
quality = this.defaultQuality;
}
// Scale the image to the new dimensions.
RenderedImage shrunkImage = this.imageProcessor.scaleImage(image, dimensions[0], dimensions[1]);
// Create an image attachment for the shrunk image.
XWikiAttachment thumbnail = (XWikiAttachment) attachment.clone();
thumbnail.loadContent(context);
OutputStream acos = thumbnail.getAttachment_content().getContentOutputStream();
this.imageProcessor.writeImage(shrunkImage, attachment.getMimeType(context), quality, acos);
IOUtils.closeQuietly(acos);
return thumbnail;
}
/**
* @param attachment an image attachment
* @param context the XWiki context
* @return the height of the specified image
* @throws IOException if reading the image from the attachment content fails
* @throws XWikiException if reading the attachment content fails
*/
public int getHeight(XWikiAttachment attachment, XWikiContext context)
throws IOException, XWikiException {
return this.imageProcessor.readImage(attachment.getContentInputStream(context)).getHeight(null);
}