Java 打开pdf文件

  InputStream in = null;
  ServletOutputStream out = null;
  String filePath = this.getServlet().getServletContext()
    .getRealPath("/")
    + "pdffiles" + File.separator +"HelpManual.pdf";
  try {
   response.reset();
   out = response.getOutputStream();
   response.setContentType("application/pdf");
   
   in = new BufferedInputStream(new FileInputStream(filePath));
   int ch;
   while ((ch = in.read()) != -1) {
    out.print((char) ch);
   }
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   if (in != null) {
    in.close();
   }
   if (out != null) {
    out.flush();
    out.close();
   }
  }