public static String toUtf8String(String s) {              StringBuffer sb = new StringBuffer();              for (int i = 0; i < s.length(); i++) {                  char c = s.charAt(i);                  if (c >= 0 && c <= 255) {                      sb.append(c);                  } else {                      byte[] b;                      try {                          b = Character.toString(c).getBytes("utf-8");                      } catch (Exception ex) {                          exceptionUtil.error("将文件名中的汉字转为UTF8编码的串时错误，输入的字符串为：" + s);                          b = new byte[0];                      }                      for (int j = 0; j < b.length; j++) {                          int k = b[j];                          if (k < 0)                              k += 256;                          sb.append("%" + Integer.toHexString(k).toUpperCase());                      }                  }              }              return sb.toString();          }          /**           * 根据不同浏览器将文件名中的汉字转为UTF8编码的串,以便下载时能正确显示另存的文件名.           *            * @param s           *            原文件名           * @return 重新编码后的文件名           */          public static String toUtf8String(HttpServletRequest request, String s) {              String agent = request.getHeader("User-Agent");              try {                  boolean isFireFox = (agent != null && agent.toLowerCase().indexOf("firefox") != -1);                  if (isFireFox) {                      s = new String(s.getBytes("UTF-8"), "ISO8859-1");                  } else {                      s = StringUtil.toUtf8String(s);                      if ((agent != null && agent.indexOf("MSIE") != -1)) {                          // see http://support.microsoft.com/default.aspx?kbid=816868                          if (s.length() > 150) {                              // 根据request的locale 得出可能的编码                              s = new String(s.getBytes("UTF-8"), "ISO8859-1");                          }                      }                  }              } catch (UnsupportedEncodingException e) {                  e.printStackTrace();              }              return s;          }