String getCacheKey(
XWikiAttachment attachment,
ImageDimensions dimension,
String copyright,
String watermark,
int cropX,
int cropY,
int cropW,
int cropH)
throws NoSuchAlgorithmException {
String key =
attachment.getId()
+ "-"
+ attachment.getVersion()
+ "-"
+ getType(attachment.getMimeType(getContext()))
+ "-"
+ attachment.getDate().getTime()
+ "-"
+ dimension.getWidth()
+ "-"
+ dimension.getHeight()
+ "-"
+ getAditionalInfoHash(copyright, watermark, cropX, cropY, cropW, cropH);
return key;
}
/**
* Set the response HTTP headers common to both partial (Range) and full responses.
*
* @param attachment the attachment to get content from
* @param request the current client request
* @param response the response to write to.
* @param context the current request context
*/
private static void setCommonHeaders(
final XWikiAttachment attachment,
final XWikiRequest request,
final XWikiResponse response,
final XWikiContext context) {
// Choose the right content type
String mimetype = attachment.getMimeType(context);
response.setContentType(mimetype);
try {
response.setCharacterEncoding("");
} catch (IllegalCharsetNameException ex) {
response.setCharacterEncoding(XWiki.DEFAULT_ENCODING);
}
String ofilename = Util.encodeURI(attachment.getFilename(), context).replaceAll("\\+", "%20");
// The inline attribute of Content-Disposition tells the browser that they should display
// the downloaded file in the page (see http://www.ietf.org/rfc/rfc1806.txt for more
// details). We do this so that JPG, GIF, PNG, etc are displayed without prompting a Save
// dialog box. However, all mime types that cannot be displayed by the browser do prompt a
// Save dialog box (exe, zip, xar, etc).
String dispType = "inline";
// Determine whether the user who attached the file has Programming Rights or not.
boolean hasPR = false;
String author = attachment.getAuthor();
try {
hasPR =
context
.getWiki()
.getRightService()
.hasAccessLevel("programming", author, "XWiki.XWikiPreferences", context);
} catch (Exception e) {
hasPR = false;
}
// If the mimetype is not authorized to be displayed inline, let's force its content disposition
// to download.
if ((!hasPR && !isAuthorized(mimetype)) || "1".equals(request.getParameter("force-download"))) {
dispType = ATTACHMENT;
}
// Use RFC 2231 for encoding filenames, since the normal HTTP headers only allows ASCII
// characters.
// See http://tools.ietf.org/html/rfc2231 for more details.
response.addHeader("Content-disposition", dispType + "; filename*=utf-8''" + ofilename);
response.setDateHeader("Last-Modified", attachment.getDate().getTime());
// Advertise that downloads can be resumed
response.setHeader("Accept-Ranges", "bytes");
}
/**
* {@inheritDoc}
*
* <p>Allows to scale images server-side, in order to have real thumbnails for reduced traffic.
* The new image dimensions are passed in the request as the {@code width} and {@code height}
* parameters. If only one of the dimensions is specified, then the other one is computed to
* preserve the original aspect ratio of the image.
*
* @see XWikiDefaultPlugin#downloadAttachment(XWikiAttachment, XWikiContext)
*/
@Override
public XWikiAttachment downloadAttachment(XWikiAttachment attachment, XWikiContext context) {
if (!this.imageProcessor.isMimeTypeSupported(attachment.getMimeType(context))) {
return attachment;
}
int height = -1;
try {
height = Integer.parseInt(context.getRequest().getParameter("height"));
} catch (NumberFormatException e) {
// Ignore.
}
int width = -1;
try {
width = Integer.parseInt(context.getRequest().getParameter("width"));
} catch (NumberFormatException e) {
// Ignore.
}
float quality = -1;
try {
quality = Float.parseFloat(context.getRequest().getParameter("quality"));
} catch (NumberFormatException e) {
// Ignore.
} catch (NullPointerException e) {
// Ignore.
}
// If no scaling is needed, return the original image.
if (height <= 0 && width <= 0 && quality < 0) {
return attachment;
}
try {
// Transform the image attachment before is it downloaded.
return downloadImage(attachment, width, height, quality, context);
} catch (Exception e) {
LOG.warn("Failed to transform image attachment.", e);
return attachment;
}
}
/**
* 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;
}
