JAVA功能代码《8》----Java创建图片的缩略图

8.Java创建图片的缩略图

public void createThumbnail(String filename, int thumbWidth,int thumbHeight, int quality, String outFilename)throws InterruptedException, FileNotFoundException, IOException {// load image from filenameImage 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 HEIGHTdouble 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-flyBufferedImage 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 outFilenameBufferedOutputStream 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();}