Question

我正在尝试访问返回带有HTTP 200状态代码的JSON对象的REST API。它与Postman一起正常工作，但是当我从Volley请求时，它每次都会给我低于误差。

E/Volley: [3766] BasicNetwork.performRequest: Unexpected response code 400 for API

这是我的代码

private void getListData() {
        showDialog();
        String url = "http://www.**********.com";
        HashMap<String, String> requestParams = new HashMap<String, String>();
        requestParams.put("SecurityKey",
                Preferences.getSecurityKey(AppointmentsListActivity.this));
        requestParams.put("ToDate", endDate);
        requestParams.put("FromDate", startDate);
        Log.i(TAG, "JSON : " + new JSONObject(requestParams));
        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
                url, new JSONObject(requestParams),
                new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {
                        closeDialog();
                        Log.i(TAG, "onResponse : " + response.toString());
                    }
                }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, "Error: " + error.getMessage());
                closeDialog();
            }
        }) {
            @Override
            public Map<String, String> getHeaders() throws AuthFailureError {
                HashMap<String, String> headers = new HashMap<>();
              //  headers.put("Content-Type", "application/json; charset=utf-8"); also use this but didn't work
                headers.put("Content-Type", "application/json");
                return headers;
            }
        };
        App.getInstance().addToRequestQueue(jsonObjReq, "get_data");
    }

我的应用类代码

public class App extends Application {

    public static final String TAG = App.class
            .getSimpleName();

    private RequestQueue mRequestQueue;

    private static App mInstance;

    @Override
    public void onCreate() {
        super.onCreate();
        mInstance = this;
    }

    public static synchronized App getInstance() {
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(getApplicationContext());
        }

        return mRequestQueue;
    }


    public <T> void addToRequestQueue(Request<T> req, String tag) {
        // set the default tag if tag is empty
        req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
        getRequestQueue().add(req);
    }

    public <T> void addToRequestQueue(Request<T> req) {
        req.setTag(TAG);
        getRequestQueue().add(req);
    }

    public void cancelPendingRequests(Object tag) {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
}

logcat的

E/Volley: [3946] BasicNetwork.performRequest: Unexpected response code 400 for http://www.********.com
E/com.android.myappointments.ui.activity.AppointmentsListActivity: Error: null
E/Surface: getSlotFromBufferLocked: unknown buffer: 0xb8653b40

我没有显示我的Api服务

如何解决此问题？

Answer 1

删除标题

 @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            HashMap<String, String> headers = new HashMap<>();
          //  headers.put("Content-Type", "application/json; charset=utf-8"); also use this but didn't work
            headers.put("Content-Type", "application/json");
            return headers;
        }
    };

在应用程序类中添加重试策略：

 public <T> void addToRequestQueue(Request<T> req, String tag) {
    // set the default tag if tag is empty
    req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
    req.setRetryPolicy(new DefaultRetryPolicy(30000, 1, 1));
    getRequestQueue().add(req);
}

请在此处查看示例代码 - VolleyExample

如何解决E / Volley：BasicNetwork.performRequest：意外的响应代码400？

1 个答案: