Android Rest 身份验证不返回状态代码或网络响应

Posted 2023-03-10

【中文标题】Android Rest 身份验证不返回状态代码或网络响应

【英文标题】：Android Rest Authentication not returning the status code or network response

【发布时间】：2019-09-05 20:23:12

【问题描述】：

我有一个使用 django REST API 后端的 android，其中包括基于令牌的身份验证。 问题是，每当用户提供错误的电子邮件或密码时，我预计下面的代码会出现 403 错误，但 volley 库没有得到响应代码。

这是 django rest 中的支持服务。

def api_authenticate_user(request):
    try:
        email = request.data['email']
        password = request.data['password']
        user = authenticate(email=email, password=password)
        if user is not None:
            try:
                payload = jwt_payload_handler(user)
                token = jwt.encode(payload, settings.SECRET_KEY)
                user_logged_in.send(sender=user.__class__, request=request, user=user)
                user = User.objects.get(email=email)
                user_details = 'token': token, 'names': user.get_name(), 'id': user.id
                return JsonResponse(user_details, status=status.HTTP_200_OK)
            except Exception as e:
                raise e
        else:
            return JsonResponse('error': 'Invalid email address or password', 'status': status.HTTP_403_FORBIDDEN)
    except KeyError:
        return JsonResponse('error': 'Provide email and password', 'status': status.HTTP_403_FORBIDDEN)

在我的 android 应用程序中，这是我尝试获取响应代码的方式，以便我可以提醒用户输入正确的凭据。

private void UserLoginTask(final String email, final String password) 
    StringRequest request = new StringRequest(Request.Method.POST, loginUrl , new Response.Listener<String>() 
        @Override
        public void onResponse(String response) 
            try 
                JSONObject userObj = new JSONObject(response);
                userSession.initializeSession(userObj.getString("names"), email, userObj.getString("token"));
                Intent intent = new Intent(Login.this, MainActivity.class);
                startActivity(intent);
                finish();
             catch (JSONException e) 
                e.printStackTrace();
                errorText.setText("Could not process your request. Try again");
                errorText.setVisibility(View.VISIBLE);
                showProgress(false);
            
        
    , new Response.ErrorListener() 
        @Override
        public void onErrorResponse(VolleyError error) 
            System.out.println(error.networkResponse);
            if(error.networkResponse.statusCode == 403)
                errorText.setText("Invalid email address or password");
            else
                errorText.setText("Could not process your request. Try again");
            
            errorText.setVisibility(View.VISIBLE);
            showProgress(false);
        
    )
        @Override
        protected Map<String, String> getParams() throws AuthFailureError 
            Map<String, String> params = new HashMap<>();
            params.put("email", email);
            params.put("password", password);
            return params;
        
    ;

    RequestQueue queue = Volley.newRequestQueue(Login.this);
    queue.add(request);

当我尝试记录或获取 volley 错误侦听器类中所示的错误状态时，我收到此错误，表明响应网络状态为空。如何获取 403 或任何其他状态码。

2019-04-15 22:24:46.461 31397-31397/com.example.phanue.antenatal E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.phanue.antenatal, PID: 31397
    java.lang.NullPointerException: Attempt to read from field 'int com.android.volley.NetworkResponse.statusCode' on a null object reference
        at com.example.phanue.antenatal.LoginData.Login$4.onErrorResponse(Login.java:153)
        at com.android.volley.Request.deliverError(Request.java:564)
        at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:101)
        at android.os.Handler.handleCallback(Handler.java:789)
        at android.os.Handler.dispatchMessage(Handler.java:98)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6942)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)

【参考方案1】：

检查空指针以避免NullPointerException

 @Override
    public void onErrorResponse(VolleyError error) 
        if (error != null && error.networkResponse != null && error.networkResponse.statusCode == 403) 
        errorText.setText("Invalid email address or password");

    elseerrorText.setText("Could not process your request. Try again");

【讨论】：

在API中设置状态码为403后，什么情况下网络响应为空