Java 文件生成縮略圖方法一

public static void createThumbnail(String filename, int thumbWidth,             int thumbHeight, int quality, String outFilename)             throws InterruptedException, FileNotFoundException, IOException {         // load image from filename         Image image = Toolkit.getDefaultToolkit().getImage(filename);         MediaTracker mediaTracker = new MediaTracker(new Container());         mediaTracker.addImage(image, 0);         mediaTracker.waitForID(0);         // use this to test for errors at this point:         // System.out.println(mediaTracker.isErrorAny());         // determine thumbnail size from WIDTH and HEIGHT         double thumbRatio = (double) thumbWidth / (double) thumbHeight;         int imageWidth = image.getWidth(null);         int imageHeight = image.getHeight(null);         double imageRatio = (double) imageWidth / (double) imageHeight;         if (thumbRatio < imageRatio) {             thumbHeight = (int) (thumbWidth / imageRatio);         } else {             thumbWidth = (int) (thumbHeight * imageRatio);         }         // draw original image to thumbnail image object and         // scale it to the new size on-the-fly         BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight,                 BufferedImage.TYPE_INT_RGB);         Graphics2D graphics2D = thumbImage.createGraphics();         graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,                 RenderingHints.VALUE_INTERPOLATION_BILINEAR);         graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);         // save thumbnail image to outFilename         BufferedOutputStream out = new BufferedOutputStream(                 new FileOutputStream(outFilename));         JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);         JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage);         quality = Math.max(0, Math.min(quality, 100));         param.setQuality((float) quality / 100.0f, false);         encoder.setJPEGEncodeParam(param);         encoder.encode(thumbImage);         out.close();     }