结果集不执行rs.next()

为什么结果集不执行rs.next()? 结果集一直是空的 求各位大神 帮个忙吧

public class LoginDao {
public Users login(String name,String password){
Users users = null;
//连接数据库
Connection conn = ConnectDB.getConnection();
String sql = "select * from users where name = ? and password = ?";
//ResultSet rs = null;//结果集
try {
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1, name);
ps.setString(2, password);
ResultSet rs = ps.executeQuery();
System.out.println("123456778980909989789");
System.out.println(rs.first());
while (rs.next()) {
//从结果集中取出内容放到模型集合中
System.out.println("dao:" + rs.getString("name"));
System.out.println("dao:" + rs.getString("password"));
Users us = new Users();
// us.setId(rs.getInt("id"));
us.setName(rs.getString("name"));
us.setNo(rs.getString("no"));
us.setIdentity(rs.getString("identity"));
us.setClasses(rs.getString("classes"));
us.setGrade(rs.getString("grade"));
us.setSubject(rs.getString("subject"));
us.setScore(rs.getString("score"));
us.setPassword(rs.getString("password"));
//usersList.add(us);
}
// 释放此 ResultSet 对象的数据库和 JDBC 资源
rs.close();
// 释放此 PreparedStatement 对象的数据库和 JDBC 资源
conn.close();
}catch (Exception e){
e.printStackTrace();
}
return users;
}
}