来自PHP脚本的JSON响应

我正在为Android建立一个注册系统。我可以向数据库添加数据，这很好。现在，我想添加一些JSON来通知用户注册成功或出现不同的错误。即

{
  "status":"success",
  "message":"Successful Registration"

}

或

等等

这是我的php脚本

<?php
   require "init.php";
   $j = new stdClass();
   $name = $_POST['name'];
   $user_name = $_POST['user_name'];
    $user_pass = md5(md5($_POST['user_name']).$_POST['user_pass']);
    if(!$name){
    json_encode(array('status' => 'fail', 'message' => 'Please enter your    
    name'));
   }
   $sql_query = "insert into user_info    
  values('$name','$user_name','$user_pass');";

   if(mysqli_query($con,$sql_query)){

    json_encode(array('status' => 'success', 'message' => 'Successfully 
    registered'));

  }else{

   json_encode(array('status' => 'fail', 'message' => 'Could not   
   register'));
  }



 ?>

什么也没给我

有什么想法吗

---

谢谢。

首先，您应该在问题中提到您正在使用android volley库，或者至少使用标签。第二，如果您试图解析JSON响应，那么应该使用JsonObjectRequest实例来解析。假设您的php脚本发送了正确的JSON，您可以通过截击尝试一些简单而直接的方法，如下所示：

JsonObjectRequest jsonRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    response = response.getJSONObject("args");
                    String site = response.getString("site"), network = response.getString("network");
                    View view = findViewById(R.id.activity_layout);
                    Snackbar.make(view, "Site : " + site + " Network : " + network, Snackbar.LENGTH_INDEFINITE).show();
                } catch (JSONException e) {
                    Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(getBaseContext(), "Error Listener", Toast.LENGTH_LONG).show();
            }
        });

        Volley.newRequestQueue(this).add(jsonRequest);

{
  "args": {
    "network": "somenetwork", 
    "site": "code"
  }, 
  "args2": {
    ...
  }, 
  "args3": "...", 
  "args4": "..."
}

---

现在，根据您发送的JSON，您可以尝试任何组合。你也可以研究这个非常有用的方法。希望这有帮助。如果您需要更多帮助，请告诉我。

我在尝试注册时，在我的应用程序中遇到了相同的问题。我想检查用户是否注册，用户名是否可用

所以我所做的是：

PHP文件：

<?php
try {
    $handler = new PDO('mysql:host=localhost;dbname=database', 'username', 'password');
    $handler->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (Exception $e) {
    echo $e->getMessage();
    die();
}

$username = $_POST['username'];
$password=$_POST['password'];
$email = $_POST['email'];
$dateCreated = $_POST['dateCreated'];
$android_version= $_POST['android_version'];
$api_level = $_POST['api_level'];
$check = $handler->query("SELECT * FROM table WHERE username = '$username'");
$don = array();
     if($check->rowCount() > 0){
          $don = array('result' =>TRUE);
          die();
     }else{
          $don = array('result' =>FALSE);
          $handler->query("INSERT INTO table(id, username, password, email, dateCreated, activated, Android_Version, API_Level) VALUES('', '$username','$password','$email', '$dateCreated', 0, '$android_version', '$api_level')");
     }

echo json_encode($don);
?>

安卓：

私有类MyInsertDataTask扩展了AsyncTask{

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(YourActivity.this);
        pDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        pDialog.setIndeterminate(true);
        pDialog.setMessage(getString(R.string.dialog_rate_data_submit));
        pDialog.setCancelable(false);
        pDialog.setInverseBackgroundForced(true);
        pDialog.show();
    }

    @Override
    protected Boolean doInBackground(String... params) {
        nameValuePairs = new ArrayList<>();
        nameValuePairs.add(new BasicNameValuePair("username", uName));
        nameValuePairs.add(new BasicNameValuePair("password", pass));
        nameValuePairs.add(new BasicNameValuePair("email", email));
        nameValuePairs.add(new BasicNameValuePair("dateCreated", date));
        nameValuePairs.add(new BasicNameValuePair("android_version", release));
        nameValuePairs.add(new BasicNameValuePair("api_level", String.valueOf(sdkVersion)));

        try
        {
            httpClient = new DefaultHttpClient();
            httpPost = new HttpPost(AppConstant.REGISTER_URL);
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            response = httpClient.execute(httpPost);
            httpEntity = response.getEntity();
            is = httpEntity.getContent();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            StringBuilder result = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                result.append(line);
            }
            Log.e("Responce", result.toString());
            if (result != null) {
                data = new JSONObject(result.toString());
                usernameExists = data.getBoolean("result");
            }
        }
        catch(Exception e)
        {
            Log.e("Fail 1", e.toString());
        }
        return  usernameExists;
    }
    @Override
    protected void onPostExecute(Boolean aVoid) {
        super.onPostExecute(aVoid);
        pDialog.dismiss();
        if (aVoid){
            Snackbar.with(YourActivity.this).type(SnackbarType.MULTI_LINE).text(getString(R.string.username_exists_message)).color(Color.parseColor(AppConstant.ENABLED_BUTTON_COLOR)).show(getActivity());
        }else {
            Toast.makeText(YourActivity.this, getString(R.string.created_successfully), Toast.LENGTH_SHORT).show();
            Intent intent = new Intent(YourActivity.this, MainActivity.class);
            startActivity(intent);
            YourActivity.this.finish();
        }

    }
}

结果是，如果用户名存在，则会弹出一条消息，说明用户名已存在，否则用户将注册

结果:

---

我解决了！这是一个php问题。这是我的解决方案

<?php
  require "init.php";
  header('Content-type: application/json');
  $name = $_POST['name'];
  $user_name = $_POST['user_name'];
  $user_pass = md5(md5($_POST['user_name']).$_POST['user_pass']);

        $sql_query = "select * from user_info WHERE user_name  
  ='".mysqli_real_escape_string($con, $user_name)."'";

        $result = mysqli_query($con, $sql_query);   

        $results = mysqli_num_rows($result);

        if ($results){
            $don = array('result' =>"fail","message"=>"Username exists. User               
        a different one");
        }else{

            $sql_query = "insert into user_info  
       values('$name','$user_name','$user_pass');";

            if(mysqli_query($con,$sql_query)){

            $don = array('result' =>"success","message"=>"Successfully  
            registered!Well done");

            }
        }

    echo json_encode($don);

  ?>

---

“我可以向数据库添加数据，这很好。现在我想添加一些JSON”。也可以向该数据库添加？可能他的意思是他想在PHP中创建一个数组，并用JSON编码，以便在设备中显示错误消息是的，这就是我的意思！PHP返回一个字符串，但您的脚本对返回值没有任何作用。您可能想打印它或者将它分配给一个变量，然后在脚本末尾打印它的内容。好吧，我可以很容易地处理GET请求。虽然POST请求比较难…但这有点棘手。一旦你了解了凌空截击的工作原理，这其实并不难。事实上，这比其他大多数方法更容易。这是因为有了API 23，android已经弃用了Apac嘿，截击是你最好的选择，除非你正在做繁重的工作。看看这些教程，你会有很好的理解。谢谢你，先生。它是固定的：。我没有打印来自PHP的json响应。很高兴我能帮助你

<?php
try {
    $handler = new PDO('mysql:host=localhost;dbname=database', 'username', 'password');
    $handler->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (Exception $e) {
    echo $e->getMessage();
    die();
}

$username = $_POST['username'];
$password=$_POST['password'];
$email = $_POST['email'];
$dateCreated = $_POST['dateCreated'];
$android_version= $_POST['android_version'];
$api_level = $_POST['api_level'];
$check = $handler->query("SELECT * FROM table WHERE username = '$username'");
$don = array();
     if($check->rowCount() > 0){
          $don = array('result' =>TRUE);
          die();
     }else{
          $don = array('result' =>FALSE);
          $handler->query("INSERT INTO table(id, username, password, email, dateCreated, activated, Android_Version, API_Level) VALUES('', '$username','$password','$email', '$dateCreated', 0, '$android_version', '$api_level')");
     }

echo json_encode($don);
?>

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(YourActivity.this);
        pDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        pDialog.setIndeterminate(true);
        pDialog.setMessage(getString(R.string.dialog_rate_data_submit));
        pDialog.setCancelable(false);
        pDialog.setInverseBackgroundForced(true);
        pDialog.show();
    }

    @Override
    protected Boolean doInBackground(String... params) {
        nameValuePairs = new ArrayList<>();
        nameValuePairs.add(new BasicNameValuePair("username", uName));
        nameValuePairs.add(new BasicNameValuePair("password", pass));
        nameValuePairs.add(new BasicNameValuePair("email", email));
        nameValuePairs.add(new BasicNameValuePair("dateCreated", date));
        nameValuePairs.add(new BasicNameValuePair("android_version", release));
        nameValuePairs.add(new BasicNameValuePair("api_level", String.valueOf(sdkVersion)));

        try
        {
            httpClient = new DefaultHttpClient();
            httpPost = new HttpPost(AppConstant.REGISTER_URL);
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            response = httpClient.execute(httpPost);
            httpEntity = response.getEntity();
            is = httpEntity.getContent();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            StringBuilder result = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                result.append(line);
            }
            Log.e("Responce", result.toString());
            if (result != null) {
                data = new JSONObject(result.toString());
                usernameExists = data.getBoolean("result");
            }
        }
        catch(Exception e)
        {
            Log.e("Fail 1", e.toString());
        }
        return  usernameExists;
    }
    @Override
    protected void onPostExecute(Boolean aVoid) {
        super.onPostExecute(aVoid);
        pDialog.dismiss();
        if (aVoid){
            Snackbar.with(YourActivity.this).type(SnackbarType.MULTI_LINE).text(getString(R.string.username_exists_message)).color(Color.parseColor(AppConstant.ENABLED_BUTTON_COLOR)).show(getActivity());
        }else {
            Toast.makeText(YourActivity.this, getString(R.string.created_successfully), Toast.LENGTH_SHORT).show();
            Intent intent = new Intent(YourActivity.this, MainActivity.class);
            startActivity(intent);
            YourActivity.this.finish();
        }

    }
}

<?php
  require "init.php";
  header('Content-type: application/json');
  $name = $_POST['name'];
  $user_name = $_POST['user_name'];
  $user_pass = md5(md5($_POST['user_name']).$_POST['user_pass']);

        $sql_query = "select * from user_info WHERE user_name  
  ='".mysqli_real_escape_string($con, $user_name)."'";

        $result = mysqli_query($con, $sql_query);   

        $results = mysqli_num_rows($result);

        if ($results){
            $don = array('result' =>"fail","message"=>"Username exists. User               
        a different one");
        }else{

            $sql_query = "insert into user_info  
       values('$name','$user_name','$user_pass');";

            if(mysqli_query($con,$sql_query)){

            $don = array('result' =>"success","message"=>"Successfully  
            registered!Well done");

            }
        }

    echo json_encode($don);

  ?>