public static boolean createScreenShoot(String source, String target) {    File file = new File(source);    if (!file.exists()) {      System.err.println("路徑[" + source + "]對應的pdf文件不存在!");      return false;    }    try{      RandomAccessFile raf = new RandomAccessFile(file, "r");      FileChannel channel = raf.getChannel();      ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());      PDFFile pdffile = new PDFFile(buf);      int num = pdffile.getNumPages();      for(int i = 1; i < num; i++){         PDFPage page = pdffile.getPage(1);          // get the width and height for the doc at the default zoom          Rectangle rect = new Rectangle(0, 0, (int) page.getBBox()              .getWidth(), (int) page.getBBox().getHeight());          // generate the image          Image img = page.getImage(rect.width, rect.height, // width &              rect, // clip rect              null, // null for the ImageObserver              true, // fill background with white              true // block until drawing is done              );          BufferedImage tag = new BufferedImage(rect.width, rect.height,   BufferedImage.TYPE_INT_RGB);          tag.getGraphics().drawImage(img, 0, 0, rect.width, rect.height,null);          FileOutputStream out = new FileOutputStream(target+i+"jpg");          JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);          encoder.encode(tag); // JPEG編碼          out.close();      }      return true;    }catch(Exception e){      e.printStackTrace();       return true;    }

response.setContentType("application/pdf");