code: public static String[] getColumnNames(ResultSet rs) throws DbRuntimeException {
  		try {
  			ResultSetMetaData rsmd = rs.getMetaData();
  			int columnCount = rsmd.getColumnCount();
  			String[] labelNames = new String[columnCount];
  			for (int i = 0; i < labelNames.length; i++) {
  				labelNames[i] = rsmd.getColumnLabel(i + 1);
  			}
  			return labelNames;
  		} catch (Exception e) {
  			throw new DbRuntimeException("Get colunms error!", e);
  		}
  	}
docs: 获得结果集的所有列名
  
  @param rs 结果集
  @return 列名数组
  @throws DbRuntimeException SQL执行异常