Current File : //proc/309157/task/309157/root/home/waritko/yacy/htroot/ViewImage.java
// ViewImage.java
// -----------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2006
// created 03.04.2006
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageInputStream;
import net.yacy.cora.document.id.DigestURL;
import net.yacy.cora.document.id.MultiProtocolURL;
import net.yacy.cora.protocol.HeaderFramework;
import net.yacy.cora.protocol.RequestHeader;
import net.yacy.http.servlets.TemplateMissingParameterException;
import net.yacy.peers.graphics.EncodedImage;
import net.yacy.search.Switchboard;
import net.yacy.server.serverObjects;
import net.yacy.server.serverSwitch;
import net.yacy.visualization.ImageViewer;
public class ViewImage {
/** Single instance of ImageViewer */
private static final ImageViewer VIEWER = new ImageViewer();
/**
* Try parsing image from post "url" parameter (authenticated users) or from "code" parameter (non authenticated users).
* When image format is not supported, return directly image data. When
* image could be parsed, try encoding to target format specified by header
* "EXT".
*
* @param header
* request header
* @param post
* post parameters
* @param env
* environment
* @return an {@link EncodedImage} instance encoded in format specified in
* post, or an InputStream pointing to original image data.
* Return and EncodedImage with empty data when image format is not supported,
* a read/write or any other error occured while loading resource.
* @throws IOException
* when specified url is malformed.
* Sould end in a HTTP 500 error whose processing is more
* consistent across browsers than a response with zero content
* bytes.
* @throws TemplateMissingParameterException when one required parameter is missing
*/
public static Object respond(final RequestHeader header, final serverObjects post, final serverSwitch env)
throws IOException {
final Switchboard sb = (Switchboard) env;
if(post == null) {
throw new TemplateMissingParameterException("please fill at least url or code parameter");
}
String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, null);
final boolean auth = ImageViewer.hasFullViewingRights(header, sb); // handle access rights
DigestURL url = VIEWER.parseURL(post, auth);
// get the image as stream
EncodedImage encodedImage;
ImageInputStream imageInStream = null;
InputStream inStream = null;
try {
String urlExt = MultiProtocolURL.getFileExtension(url.getFileName());
if (ext != null && ext.equalsIgnoreCase(urlExt) && ImageViewer.isBrowserRendered(urlExt)) {
return VIEWER.openInputStream(post, sb.loader, auth, url);
}
/*
* When opening a file, the most efficient is to open
* ImageInputStream directly on file
*/
if (url.isFile()) {
imageInStream = ImageIO.createImageInputStream(url.getFSFile());
} else {
inStream = VIEWER.openInputStream(post, sb.loader, auth, url);
imageInStream = ImageIO.createImageInputStream(inStream);
}
// read image
encodedImage = VIEWER.parseAndScale(post, auth, url, ext, imageInStream);
} catch (Exception e) {
/*
* Exceptions are not propagated here : many error causes are
* possible, network errors, incorrect or unsupported format, bad
* ImageIO plugin... Instead return an empty EncodedImage. Caller is
* responsible for handling this correctly (500 status code
* response)
*/
encodedImage = new EncodedImage(new byte[0], ext, post.getBoolean("isStatic"));
} finally {
/*
* imageInStream.close() method doesn't close source input stream
*/
if (inStream != null) {
try {
inStream.close();
} catch (IOException ignored) {
}
}
}
return encodedImage;
}
}
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