diff -r 4634176c6602 -r 505031965440 java/copy-image-resizer/src/cz/frantovo/copyImageResizer/JavaSingleImageResizer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/copy-image-resizer/src/cz/frantovo/copyImageResizer/JavaSingleImageResizer.java	Mon Nov 17 21:59:20 2014 +0100
@@ -0,0 +1,127 @@
+/**
+ * copy-image-resizer
+ * Copyright © 2014 František Kučera (frantovo.cz)
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+package cz.frantovo.copyImageResizer;
+
+import java.awt.Graphics2D;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.regex.Pattern;
+import javax.imageio.ImageIO;
+
+/**
+ *
+ * @author Ing. František Kučera (frantovo.cz)
+ */
+public class JavaSingleImageResizer implements SingleImageResizer {
+
+	private static final Logger log = Logger.getLogger(SingleImageResizer.class.getName());
+
+	@Override
+	public boolean resize(InputStream input, OutputStream output, SizeSpecification size, ImageFormat outputFormat) throws ResizeException {
+		try {
+			BufferedImage image = readImage(input);
+			if (shouldResize(image, size)) {
+				BufferedImage resized = resize(image, size.getWidth(), size.getHeight(), image.getType());
+				ImageIO.write(resized, outputFormat.getFormat(), output);
+				return true;
+			} else {
+				return false;
+			}
+		} catch (IOException e) {
+			throw new ResizeException("Error while resizing image", e);
+		}
+	}
+
+	private BufferedImage resize(BufferedImage original, int maxWidth, int maxHeight, int type) {
+
+		int width;
+		int height;
+		float aspectRatio = (float) original.getWidth() / (float) original.getHeight();
+
+		if (aspectRatio > 1) {
+			width = maxWidth;
+			height = Math.max(Math.round(maxWidth / aspectRatio), 1);
+		} else {
+			width = Math.max(Math.round(maxHeight * aspectRatio), 1);
+			height = maxHeight;
+		}
+
+		if (type == BufferedImage.TYPE_CUSTOM) {
+			log.log(Level.FINER, "Setting default image type: from TYPE_CUSTOM to TYPE_INT_ARGB");
+			type = BufferedImage.TYPE_INT_ARGB;
+		}
+
+		BufferedImage resized = new BufferedImage(width, height, type);
+		Graphics2D g = resized.createGraphics();
+		g.drawImage(original, 0, 0, width, height, null);
+		g.dispose();
+
+		return resized;
+	}
+
+	private static BufferedImage readImage(InputStream input) throws ResizeException {
+		try {
+			return ImageIO.read(input);
+		} catch (IOException e) {
+			throw new ResizeException("Unable to read image from stream", e);
+		}
+	}
+
+	private static boolean shouldResize(BufferedImage input, SizeSpecification requested) {
+		if (requested.isResizeSmaller()) {
+			return input.getHeight() != requested.getHeight() || input.getWidth() != requested.getWidth();
+		} else {
+			return input.getHeight() > requested.getHeight() || input.getWidth() > requested.getWidth();
+		}
+	}
+
+	public static enum ImageFormat {
+
+		JPEG("jpg", Pattern.compile(".*\\.(jpg|jpeg)$", Pattern.CASE_INSENSITIVE)),
+		PNG("png", Pattern.compile(".*\\.png$", Pattern.CASE_INSENSITIVE)),
+		GIF("gif", Pattern.compile(".*\\.gif$", Pattern.CASE_INSENSITIVE));
+
+		private final String format;
+		private final Pattern regex;
+
+		private ImageFormat(String format, Pattern regex) {
+			this.format = format;
+			this.regex = regex;
+		}
+
+		/**
+		 * @return format name for {@linkplain ImageIO#write(java.awt.image.RenderedImage, java.lang.String, java.io.File)
+		 */
+		public String getFormat() {
+			return format;
+		}
+
+		public static ImageFormat getMatching(String fileName) {
+			for (ImageFormat type : values()) {
+				if (type.regex.matcher(fileName).matches()) {
+					return type;
+				}
+			}
+			return null;
+		}
+	}
+}