ORM原理：

  static List<Object> getObjects(String sql, Class clazz)
      throws SQLException, Exception, IllegalAccessException,
      InvocationTargetException {
    Connection conn = null;
    PreparedStatement ps = null;
    ResultSet rs = null;
    try {
      conn = JdbcUtils.getConnection();
      ps = conn.prepareStatement(sql);
      rs = ps.executeQuery();
      String[] colNames = getColNames(rs);

      List<Object> objects = new ArrayList<Object>();
      Method[] ms = clazz.getMethods();
      while (rs.next()) {
        Object object = clazz.newInstance();
        for (int i = 0; i < colNames.length; i++) {
          String colName = colNames[i];
          String methodName = "set" + colName;
          // Object value = rs.getObject(colName);
          // try {
          // Method m = clazz
          // .getMethod(methodName, value.getClass());
          // if (m != null)
          // m.invoke(object, value);
          // } catch (NoSuchMethodException e) {
          // e.printStackTrace();
          // //
          // }
          for (Method m : ms) {
            if (methodName.equals(m.getName())) {
              m.invoke(object, rs.getObject(colName));
              break;
            }
          }
          objects.add(object);
        }
      }
      return objects;
    } finally {
      JdbcUtils.free(rs, ps, conn);
    }
  }

  private static String[] getColNames(ResultSet rs) throws SQLException {
    ResultSetMetaData rsmd = rs.getMetaData();
    int count = rsmd.getColumnCount();
    String[] colNames = new String[count];
    for (int i = 1; i <= count; i++) {
      colNames[i - 1] = rsmd.getColumnLabel(i);
    }
    return colNames;
  }