不同瀏覽器下載文件時，設置文件名

public String setFileDownloadHeader(HttpServletRequest request, String fileName) throws UnsupportedEncodingException
    {
        final String agent = request.getHeader("USER-AGENT");
        String filename = fileName;
        if (agent.contains("MSIE"))
        {
            // IE瀏覽器
            filename = URLEncoder.encode(filename, "utf-8");
            filename = filename.replace("+", " ");
        }
        else if (agent.contains("Firefox"))
        {
            // 火狐瀏覽器
            filename = new String(fileName.getBytes(), "ISO8859-1");
        }
        else if (agent.contains("Chrome"))
        {
            // google瀏覽器
            filename = URLEncoder.encode(filename, "utf-8");
        }
        else
        {
            // 其它瀏覽器
            filename = URLEncoder.encode(filename, "utf-8");
        }
        return filename;
    }