code: public static String getMapParamOrEmpty(Map<String,String[]> map, 
  			String param) {
  		String val = getMapParam(map, param);
  		return (val == null) ? "" : val;
  	}
docs: Extract the first value in the array mapped to by field in queryMap
  @param map the Map in which to search
  @param param the field value desired
  @return the first value in the array mapped to field in queryMap, if
  present, or an empty string otherwise