code: public static String buildUrlQuery(String baseUrl, Map<String, String> params) {
  	if (baseUrl.isEmpty() || params.isEmpty()) {
  	    return baseUrl;
  	} else {
  	    String query = baseUrl;
  	    query += QUERY_STRING_SEPARATOR;
  
  	    for (String key : params.keySet()) {
  		query += key;
  		query += PAIR_SEPARATOR;
  		query += encodeString(params.get(key));
  		query += PARAM_SEPARATOR;
  	    }
  
  	    return query.substring(0, query.length() - 1);
  	}
      }
docs: Builds the URL String.
  
  @param baseUrl
  the base URL.
  @param params
  the URL parameter.
  @return the URL as String.