Refactoring : default favicon and image processing errors.

- moved default favicon processing from ViewImage to
yacysearchitem.html : when previewing ico image search results we don't
want a default favicon be displayed
 - throw an IOException ending in a HTTP 500 error when image processing
fails, rather than returning a null result : behavior is more consistent
accross browsers (for exempla Chrome and Firefox), especially with new
default favicon display system

htroot/ViewImage.java

@@ -29,9 +29,7 @@ import java.awt.MediaTracker;
 import java.awt.image.BufferedImage;
 import java.awt.image.Raster;
 import java.io.ByteArrayInputStream;
-import java.io.File;
 import java.io.IOException;
-import java.net.MalformedURLException;
 import java.util.Map;
 
 import net.yacy.cora.document.id.DigestURL;
@@ -45,7 +43,6 @@ import net.yacy.cora.storage.ConcurrentARC;
 import net.yacy.cora.util.ConcurrentLog;
 import net.yacy.data.URLLicense;
 import net.yacy.document.ImageParser;
-import net.yacy.kelondro.util.FileUtils;
 import net.yacy.kelondro.util.MemoryControl;
 import net.yacy.kelondro.workflow.WorkflowProcessor;
 import net.yacy.peers.graphics.EncodedImage;
@@ -58,17 +55,30 @@ public class ViewImage {
 
 	private static Map<String, Image> iconcache = new ConcurrentARC<String, Image>(1000,
 			Math.max(10, Math.min(32, WorkflowProcessor.availableCPU * 2)));
-	private static String defaulticon = "htroot/env/grafics/dfltfvcn.ico";
-	private static byte[] defaulticonb;
 
-	static {
+	/**
-		try {
+	 * Try parsing image from post "url" parameter or from "code" parameter.
-			defaulticonb = FileUtils.read(new File(defaulticon));
+	 * When image format is not supported, return directly image data. When
-		} catch (final IOException e) {
+	 * image could be parsed, try encoding to target format specified by header
-		}
+	 * "EXT".
-	}
+	 * 
-
+	 * @param header
-	public static Object respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
+	 *            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
+	 * @throws IOException
+	 *             when specified url is malformed, or a read/write error
+	 *             occured, or input or target image format is not supported.
+	 *             Sould end in a HTTP 500 error whose processing is more
+	 *             consistent across browsers than a response with zero
+	 *             content bytes.
+	 */
+	public static Object respond(final RequestHeader header, final serverObjects post, final serverSwitch env)
+			throws IOException {
 
 		final Switchboard sb = (Switchboard) env;
 
@@ -85,25 +95,13 @@ public class ViewImage {
 				|| sb.verifyAuthentication(header); // handle access rights
 
 		DigestURL url = null;
-		if ((urlString.length() > 0) && (auth))
+		if ((urlString.length() > 0) && (auth)) {
-			try {
+			url = new DigestURL(urlString);
-				url = new DigestURL(urlString);
+		}
-			} catch (final MalformedURLException e1) {
-				url = null;
-			}
 
 		if ((url == null) && (urlLicense.length() > 0)) {
 			urlString = URLLicense.releaseLicense(urlLicense);
-			try {
+			url = new DigestURL(urlString);
-				url = new DigestURL(urlString);
-			} catch (final MalformedURLException e1) {
-				url = null;
-				urlString = null;
-			}
-		}
-
-		if (urlString == null) {
-			return null;
 		}
 
 		// get the image as stream
@@ -125,28 +123,15 @@ public class ViewImage {
 							BlacklistType.SEARCH, agent);
 				} catch (final IOException e) {
 					ConcurrentLog.fine("ViewImage", "cannot load: " + e.getMessage());
+					throw e;
 				}
 			boolean okToCache = true;
 			if (resourceb == null) {
-				if (urlString.endsWith(".ico")) {
+				/*
-					// load default favicon dfltfvcn.ico
+				 * Throw an exception, wich will end in a HTTP 500 response,
-					// Should not do this here : we can be displaying search
+				 * better handled by browsers than an empty image
-					// image result of '.ico' type and do not want to display a
+				 */
-					// default
+				throw new IOException("Image could not be loaded.");
-					if (defaulticonb == null)
-						try {
-							resourceb = FileUtils.read(new File(sb.getAppPath(), defaulticon));
-							okToCache = false;
-						} catch (final IOException e) {
-							return null;
-						}
-					else {
-						resourceb = defaulticonb;
-						okToCache = false;
-					}
-				} else {
-					return null;
-				}
 			}
 
 			String urlExt = MultiProtocolURL.getFileExtension(url.getFileName());
@@ -180,8 +165,8 @@ public class ViewImage {
 	}
 
 	/**
-	 * Process resourceb byte array to try to produce an Image instance
+	 * Process resourceb byte array to try to produce an EncodedImage instance
-	 * eventually scaled and cropped depending on post parameters
+	 * eventually scaled and cropped depending on post parameters.
 	 * 
 	 * @param post
 	 *            request post parameters. Must not be null.
@@ -195,13 +180,22 @@ public class ViewImage {
 	 *            true when image can be cached
 	 * @param resourceb
 	 *            byte array. Must not be null.
-	 * @return an Image instance when parsing is OK, or null.
+	 * @return an EncodedImage instance.
+	 * @throws IOException
+	 *             when image could not be parsed or encoded to specified format
 	 */
 	protected static EncodedImage parseAndScale(serverObjects post, boolean auth, String urlString, String ext,
-			boolean okToCache, byte[] resourceb) {
+			boolean okToCache, byte[] resourceb) throws IOException {
 		EncodedImage encodedImage = null;
 
 		Image image = ImageParser.parse(urlString, resourceb);
+		if (image == null) {
+			/*
+			 * Throw an exception, wich will end in a HTTP 500 response, better
+			 * handled by browsers than an empty image
+			 */
+			throw new IOException("Image format is not supported.");
+		}
 
 		if (image != null) {
 			int maxwidth = post.getInt("maxwidth", 0);
@@ -242,16 +236,18 @@ public class ViewImage {
 					iconcache.put(urlString, image);
 				}
 			}
-			/* An error can still occur when transcoding from buffered image to target ext : in that case return null */
+			/*
+			 * An error can still occur when transcoding from buffered image to
+			 * target ext : in that case return null
+			 */
 			encodedImage = new EncodedImage(image, ext, isStatic);
-			if(encodedImage.getImage().length() == 0) {
+			if (encodedImage.getImage().length() == 0) {
-				encodedImage = null;
+				throw new IOException("Image could not be encoded to format : " + ext);
 			}
 		}
 		return encodedImage;
 	}
 
-
 	/**
 	 * Calculate image dimensions from image original dimensions, max
 	 * dimensions, and target dimensions.

htroot/env/base.css

@@ -389,7 +389,7 @@ h4.linktitle {
   padding-left: 20px;
 }
 
-img.favicon{
+img.favicon, object.favicon {
   margin: 0px 4px 0px -20px;
   width: 16px;
   height: 16px;

htroot/env/oldie.css

@@ -1,6 +1,6 @@
 /* Fixes for IE 5 and lower */
 
 /* IE 5 and lower can't display favicons, so hide them */
-img.favicon {
+img.favicon, object.favicon {
   display: none;
 }

htroot/yacy/ui/css/base.css

@@ -109,7 +109,7 @@ div.ys {
 img {
   vertical-align: top;
 }
-img.favicon{  
+img.favicon, object.favicon {  
   width: 16px;
   height: 16px;
   vertical-align: middle;  

htroot/yacy/ui/css/widget.css

@@ -27,7 +27,7 @@ a.favicon {
   	color:#20A020;
   	text-decoration:none;
 }
-img.favicon{  
+img.favicon, object.favicon {  
   width: 16px;
   height: 16px;
   vertical-align: middle;

htroot/yacysearchitem.html

@@ -1,7 +1,9 @@
 #(content)#::
   <div class="searchresults">
   <h4 class="linktitle">
-  <img width="16" height="16" src="ViewImage.png?width=16&amp;height=16&amp;code=#[faviconCode]#&amp;isStatic=true" id="f#[urlhash]#" class="favicon" style="width:16px; height:16px;" alt="" />
+  <object data="ViewImage.png?width=16&amp;height=16&amp;code=#[faviconCode]#&amp;isStatic=true" type="image/png" id="f#[urlhash]#" class="favicon" style="width:16px; height:16px;">
+  	<img width="16" height="16" src="env/grafics/dfltfvcn.ico" style="width:16px; height:16px;" alt="" />
+  </object>
   <a href="#[link]#" target="#[target]#">#[title]#</a></h4>
   <div class="urlactions">
     #(heuristic)#::