public static String buildParameterStr(Collection<Parameter> parameters) {
		StringBuilder sb = new StringBuilder("");
		if (parameters != null && parameters.size() > 0) {
			for (Parameter param : parameters) {
				sb.append(param.getKey());
				sb.append("=");
				try {
					sb.append(param.getValue() != null
							&& !param.getValue().isEmpty() ? URLEncoder.encode(
							param.getValue(), "UTF-8") : "");
				} catch (UnsupportedEncodingException e) {
					e.printStackTrace();
					sb.append("");
				}
				sb.append("&");
			}
			sb.deleteCharAt(sb.length() - 1);
		}
		return sb.toString();
	}