JAVA JDBC 查询数据

String sql = "select id,name,email,birth from customers where id = ?";
ps = connection.prepareStatement(sql);
ps.setObject(1,1);
ResultSet rs = ps.executeQuery();
if(rs.next()){
      int id = rs.getInt(1);
      String name = rs.getString(2);
      String email = rs.getString(3);
      Date birth = rs.getDate(4);
      System.out.println(id+name+email+birth);
}