使用时，
PdfStamper它是从磁盘读取文件并将其写入
baos。当您删除时
PdfStamper，
baos切勿写入。因此，当然
baos是空的，因此永远不会实际返回任何东西。
编辑：您要实际执行此操作（仅当您要修改PDF时才需要PdfReader）：
private static void copy(InputStream is, OutputStream os) throws IOException{ byte buffer[] = new byte[8192]; int bytesRead, i; while ((bytesRead = is.read(buffer)) != -1) { os.write(buffer, 0, bytesRead); }}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { FileInputStream baos = new FileInputStream(document_LOCATION); // set some response headers response.setHeader("Expires", "0"); response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0"); response.setHeader("Pragma", "public"); response.setContentType("application/pdf"); response.setContentLength(new File(document_LOCATION).length()); OutputStream os = response.getOutputStream(); copy(baos, os); os.flush(); os.close(); } }
