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;
    }

没有问题，请检查数据库中表的设计。

正确。。

看不出错来

这个代码是没有问题的！！
看下你的数据咯。。。。。
当然你可以把你的每条数据都可以输出来看下，检查数据库是否有数据。。