code: public List<Map<String, Object>> toList(List<Object[]> table, String[] columns, Map<String, Object> defaultMap) {
  		List<Map<String, Object>> resultList = toList(table, columns);
  
  		for (Map<String, Object> resultItem : resultList) {
  			Set<String> keySet = defaultMap.keySet();
  			for (String key : keySet) {
  				if (resultItem.containsKey(key)) {
  					Object value = resultItem.get(key);
  					if (value == null || StringUtils.isEmpty(value.toString())) {
  						Object defaultValue = defaultMap.get(key);
  						if (defaultValue != null) {
  							resultItem.put(key, defaultValue);
  						}
  					}
  				}
  			}
  		}
  
  		return resultList;
  	}
docs: 将查询结果映射成为List，并支持当字段为空值时进行默认值设定
  
  @param table 查询结果
  @param columns 列名（按查询结果顺序）
  @param defaultMap 默认值
  
  @return 映射后的List