code: public static String createAutoFormHtml(String reqUrl, Map<String, String> hiddens,String encoding) {
  		StringBuffer sf = new StringBuffer();
  		sf.append("<html><head><meta http-equiv=\"Content-Type\" content=\"text/html; charset="+encoding+"\"/></head><body>");
  		sf.append("<form id = \"pay_form\" action=\"" + reqUrl
  				+ "\" method=\"post\">");
  		if (null != hiddens && 0 != hiddens.size()) {
  			Set<Entry<String, String>> set = hiddens.entrySet();
  			Iterator<Entry<String, String>> it = set.iterator();
  			while (it.hasNext()) {
  				Entry<String, String> ey = it.next();
  				String key = ey.getKey();
  				String value = ey.getValue();
  				sf.append("<input type=\"hidden\" name=\"" + key + "\" id=\""
  						+ key + "\" value=\"" + value + "\"/>");
  			}
  		}
  		sf.append("</form>");
  		sf.append("</body>");
  		sf.append("<script type=\"text/javascript\">");
  		sf.append("document.all.pay_form.submit();");
  		sf.append("</script>");
  		sf.append("</html>");
  		return sf.toString();
  	}
docs: 功能：前台交易构造HTTP POST自动提交表单<br>
  @param action 表单提交地址<br>
  @param hiddens 以MAP形式存储的表单键值<br>
  @param encoding 上送请求报文域encoding字段的值<br>
  @return 构造好的HTTP POST交易表单<br>