code: protected String buildParamsQuery(final Map<String, String> params)
  			throws UnsupportedEncodingException {
  		StringBuilder builder = new StringBuilder();
  		if (params.isEmpty()) {
  			return builder.toString();
  		}
  
  		String sep = "";
  		for (Map.Entry<String, String> entry : params.entrySet()) {
  			builder.append(sep);
  			builder.append(urlencode(entry.getKey()));
  			builder.append("=");
  			builder.append(urlencode(entry.getValue()));
  			sep = "&";
  		}
  
  		return builder.toString();
  	}
docs: Builds a urlencoded query string from a param map.