大家给我看看这有错误吗 怎么list里面就没有值呀？？

public List<Zc>geren(String username) {
        Zc zc = null;
        List<Zc> list = new ArrayList<Zc>();
   
        conn = Base.getInstance().getConnection();
        try {
            ps = conn.prepareStatement("SELECT * FROM userinfo where UserName=?");
            ps.setString(1, username);   
            rs = ps.executeQuery();
            while (rs.next()) {
                zc = new Zc();
                zc.setName(rs.getString("UserName"));
                zc.setPassword(rs.getString("Password"));
                zc.setTruename(rs.getString("RealName"));
                zc.setId(rs.getString("IdentityCard"));
                zc.setGuojia(rs.getString("Country"));
                zc.setChengshi(rs.getString("City"));
                zc.setAddress(rs.getString("Address"));
                zc.setPostCode(rs.getString("Zip"));
                zc.setPhone(rs.getString("Phone"));
                zc.setEmail(rs.getString("Email"));
                list.add(zc);
            }
            rs.close();
            ps.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }