Fixed JPEG snapshot resizing when running on OpenJDK.

Resizing JPEG snapshot images through /api/snapshot.jpg failed when
running on OpenJDK, but rendered successfully with a Oracle JDK.
Details in mantis 772 ( http://mantis.tokeek.de/view.php?id=772 ).

Removing any alpha component (useless in snapshot images) from the
rendered resized image solves the issue.

htroot/api/snapshot.java

@@ -21,6 +21,7 @@
 import java.awt.Container;
 import java.awt.Image;
 import java.awt.MediaTracker;
+import java.awt.image.BufferedImage;
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.IOException;
@@ -312,7 +313,14 @@ public class snapshot {
                     final MediaTracker mediaTracker = new MediaTracker(new Container());
                     mediaTracker.addImage(scaled, 0);
                     try {mediaTracker.waitForID(0);} catch (final InterruptedException e) {}
-                    return new EncodedImage(scaled, ext, true);
+                    
+					/*
+					 * Ensure there is no alpha component on the ouput image, as it is pointless
+					 * here and it is not well supported by the JPEGImageWriter from OpenJDK
+					 */
+					BufferedImage scaledBufferedImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
+                    scaledBufferedImg.createGraphics().drawImage(scaled, 0, 0, width, height, null);
+                    return new EncodedImage(scaledBufferedImg, ext, true);
                 } catch (IOException e) {
                     ConcurrentLog.logException(e);
                     return null;

source/net/yacy/peers/graphics/EncodedImage.java

@@ -20,7 +20,6 @@
 
 package net.yacy.peers.graphics;
 
-import java.awt.Image;
 import java.awt.image.BufferedImage;
 import java.awt.image.ColorConvertOp;
 import java.io.ByteArrayOutputStream;
@@ -90,30 +89,6 @@ public class EncodedImage {
         
     }
     
-    /**
-     * set an encoded image from a buffered image. Image ByteBuffer will be empty when encoding format is not supported.
-     * @param sourceImage the image
-     * @param targetExt the target extension of the image when converted into a file
-     * @param isStatic shall be true if the image will never change, false if not
-     */
-    public EncodedImage(final Image i, final String targetExt, final boolean isStatic) {
-        this.extension = targetExt;
-        this.isStatic = isStatic;
-        
-        // generate an byte array from the generated image
-        int width = i.getWidth(null);
-        if (width < 0) {
-            width = 96; // bad hack
-        }
-        int height = i.getHeight(null);
-        if (height < 0) {
-            height = 96; // bad hack
-        }
-        final BufferedImage sourceImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
-        sourceImage.createGraphics().drawImage(i, 0, 0, width, height, null);
-        this.image = RasterPlotter.exportImage(sourceImage, targetExt);
-    }
-    
     /**
      * set an encoded image from an animated GIF. The target extension will be "gif"
      * @param sourceImage the image