下载文件downloadFile

public static void downLoadFile(InputStream inStream, String fileName)

  {

    if (StringUtils.isBlank(fileName)) {

      fileName = UUID.randomUUID().toString().replaceAll("-", "");

    }

    HttpServletRequest req = getRequest();

    String agent = req.getHeader("User-Agent");

    boolean isMSIE = (agent != null) && (agent.indexOf("MSIE") != -1);

    try

    {

      if (isMSIE) {

        fileName = URLEncoder.encode(fileName, "UTF-8");

        fileName = fileName.replace("+", "%20");

      } else {

        fileName = new String(fileName.getBytes("UTF-8"), "ISO-8859-1");

      }

    } catch (UnsupportedEncodingException e) {

      e.printStackTrace();

    }

    HttpServletResponse response = getResponse();

    response.setCharacterEncoding("UTF-8");

    response.setHeader("content-disposition", "attachment;filename=\"" + fileName + "\"");

    response.setContentType("application/octet-stream");

    OutputStream outStream = null;

    try {

      outStream = response.getOutputStream();

      byte[] cache = new byte[1024];

      int length = inStream.read(cache);

      while (length != -1) {

        outStream.write(cache, 0, length);

        length = inStream.read(cache);

      }

    } catch (IOException e) {

      e.printStackTrace();

      try

      {

        outStream.flush();

      } catch (IOException e) {

        e.printStackTrace();

      }

      try {

        outStream.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

      try {

        inStream.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

    }

    finally

    {

      try

      {

        outStream.flush();

      } catch (IOException e) {

        e.printStackTrace();

      }

      try {

        outStream.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

      try {

        inStream.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

    }

  }

public static HttpServletRequest getRequest()

  {

    ActionContext ac = ActionContext.getContext();

    HttpServletRequest req = null;

    if (ac != null) {

      req = (HttpServletRequest)ac.get("com.opensymphony.xwork2.dispatcher.HttpServletRequest");

    }

    return req;

  }

public static HttpServletResponse getResponse()

  {

    ActionContext ac = ActionContext.getContext();

    HttpServletResponse response = (HttpServletResponse)ac.get("com.opensymphony.xwork2.dispatcher.HttpServletResponse");

    return response;

  }