java - 如何将 php 变量返回给 android 应用程序？

Question

我是 Android Studio 编程的新手，我正在尝试将我的应用程序连接到 Web 服务器上的 MySQL 数据库，echo "login success !!!!! Welcome $user"; 是正如我所愿，工作正常，但我想得到一个像 $user 这样的 PHP 变量也回到我的 android studio 开发中，这样我就可以用它在应用程序中创建 session ，但我无法获取变量我得到了 echo ，我在其他地方使用它来显示登录成功。需要帮助谢谢

    <?php
    require "pconn.php";
    $username = $_POST["username"];
    $password = $_POST["password"];

    $username = stripslashes($username);
    $password = stripslashes($password);

    $hash = md5($password);

    $qry = "SELECT * FROM UserLogin WHERE Email='".$username."' and BINARY Password ='".$hash."'";
   $result = mysqli_query($conn ,$qry);
   if(mysqli_num_rows($result) > 0) {
   $row = mysqli_fetch_assoc($result);
   $user = $row['Username'] ;
   echo "login success !!!!! Welcome $user";
   echo $user;
   }
   else {
   echo "login not success";
   }


   ?>

我的 Java 类是:

protected String doInBackground(String... params) {
        String type = params[0];
        String login_url = "http://xaas.com/login.php";
        if(type.equals("login")) {
            try {
                String username = params[1];
                String password = params[2];
                URL url = new URL(login_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                httpURLConnection.setDoInput(true);
                OutputStream outputStream = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
                String post_data = URLEncoder.encode("username","UTF-8")+"="+URLEncoder.encode(username,"UTF-8")+"&"
                        +URLEncoder.encode("password","UTF-8")+"="+URLEncoder.encode(password,"UTF-8");
                bufferedWriter.write(post_data);
                bufferedWriter.flush();
                bufferedWriter.close();
                outputStream.close();
                InputStream inputStream = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
                String result="";
                String line="";

                while((line = bufferedReader.readLine())!= null) {
                    result += line;
                }



                bufferedReader.close();
                inputStream.close();
                httpURLConnection.disconnect();
                return result;
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

Answer 1

使用print用于向 php 控制台显示任何内容，而 echo 只是您要作为对 android 设备的响应发送的部分。

或者，如果您想发送 "login success !!!!! Welcome $user" 字符串作为响应。然后在android端简单地获取$user的值。

第一次执行 echo 时，将作为响应发送。如果你想发送多个字符串，那么构建一个 json，用你想发送的任何内容填充它，最后回显它。像这样:

$data = [ 'loginMessage' => 'login success !!!!! Welcome $user', 'user' => '$user' ];
header('Content-type: application/json');
echo json_encode( $data );

然后使用 JSONObject 在 android 端取回值:

JSONObject responseJSON = new JSONObject(result);
String loginMessage = responseJSON.getString("loginMessage");
String userName = responseJSON.getString("user");