Map转化成url拼接请求参数

public String buildMap(Map map) {
        StringBuffer sb = new StringBuffer();
        if (map.size() > 0) {
            for (String key : map.keySet()) {
                sb.append(key + "=");
                if (StringUtils.isEmpty(map.get(key))) {
                    sb.append("&");
                } else {
                    String value = map.get(key);
                    try {
                        value = URLEncoder.encode(value, "UTF-8");
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }
                    sb.append(value + "&");
                }
            }
        }
        return sb.toString();
    }