个人作业8

今天完成了教师端相关功能，在登录功能中添加了识别区分账号功能，登陆时自动区分学生和教师，学生进入学生端教师进入教师端。

 

 public int login(String userAccount, String userPassword){

        HashMap<String, Object> map = new HashMap<>();
        // 根据数据库名称，建立连接
        Connection connection = JDBCUtils.getConn();
        int msg = 0;
        try {
            // mysql简单的查询语句。这里是根据user表的userAccount字段来查询某条记录
            String sql = "select * from user where userAccount = ?";
            if (connection != null){// connection不为null表示与数据库建立了连接
                PreparedStatement ps = connection.prepareStatement(sql);
                if (ps != null){
                    Log.e(TAG,"账号：" + userAccount);
                    //根据账号进行查询
                    ps.setString(1, userAccount);
                    // 执行sql查询语句并返回结果集
                    ResultSet rs = ps.executeQuery();
                    int count = rs.getMetaData().getColumnCount();
                    //将查到的内容储存在map里
                    while (rs.next()){
                        // 注意：下标是从1开始的
                        for (int i = 1;i <= count;i++){
                            String field = rs.getMetaData().getColumnName(i);
                            map.put(field, rs.getString(field));
                        }
                    }


                    if (map.size()!=0){
                        StringBuilder s = new StringBuilder();
                        //寻找密码是否匹配
                        for (String key : map.keySet()){
                            if(key.equals("userPassword")){
                                if(userPassword.equals(map.get(key))){
                                   // msg = 1;//密码正确
                                    String sql1 = "select * from user where userType = ? and userAccount= ?";
                                   // select * from yonghu1 where id=? and name=? and password=?
                                    ps = connection.prepareStatement(sql1);
                                    ps.setInt(1, 0);
                                    ps.setString(2,userAccount);
                                    rs = ps.executeQuery();
                                    if(rs.next()){
                                        msg=1;
                                    }else{
                                        msg = 4;//密码正确
                                    }

                                    connection.close();
                                    ps.close();

                                }
                                else
                                    msg = 2;            //密码错误
                                break;
                            }
                        }
                    }else {
                        Log.e(TAG, "查询结果为空");
                        msg = 3;
                    }
                }else {
                    msg = 0;
                }
            }else {
                msg = 0;
            }
        }catch (Exception e){
            e.printStackTrace();
            Log.d(TAG, "异常login：" + e.getMessage());
            msg = 0;
        }
        return msg;
    }