'如何使用带有“Content-Type”的 Volley 发送 Post 请求：“application/x-www-form-urlencoded”

Question

I am trying to send a POST Request using Volley with the following:

headers:

{
"Content-Type": "application/x-www-form-urlencoded"
}

(Form Data)

grant_type=password&client_id=acme&client_secret=acmesecret&username=ayan@vvv.in&password=%2523

But I am always getting this error: E/Volley: [26219] BasicNetwork.performRequest: Unexpected response code 400

Here is my code

 RequestQueue queue = Volley.newRequestQueue(mContext);
    StringRequest jsonObjRequest = new StringRequest(Request.Method.POST, getResources().getString(R.string.base_url), new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            String resp = response.toString();
            Log.e(TAG,"Response***"+resp);
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

        }
    }) {

        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            Map<String,String> params = new HashMap<String, String>();
            params.put("Content-Type","application/x-www-form-urlencoded");
            return params;
        }

        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
            Map<String, String> params = new HashMap<String, String>();
            params.put("grant_type", "password");
            params.put("client_id", "acme");
            params.put("client_secret", "acmesecret");
            params.put("username", "ayan@vvv.in");
            params.put("password", "%2523");
            return params;
        }

    };
    queue.add(jsonObjRequest);
}

Answer 1

There are several causes to have

Volley: [26219] BasicNetwork.performRequest: Unexpected response code 400

You can check factors given in the below

1.If URL contains blank space then add this code to be safe

String url = "Your URL Link";

url = url.replaceAll(" ", "%20");

StringRequest stringRequest = new StringRequest(Request.Method.POST, getResources().getString(R.string.base_url),
                        new com.android.volley.Response.Listener<String>() {
                            @Override
                            public void onResponse(String response) {
                            ...
                            ...
                            ...

2.Also, you can try by appending an extra '/' to your URL, eg:

String url = "http://www.google.com" 

To

String url = "http://www.google.com/"

3.You can do something similar to this in your error listener to check for the response data in the VolleyError and parse it your self.

    /* import com.android.volley.toolbox.HttpHeaderParser; */
    public void onErrorResponse(VolleyError error) {

    // As of f605da3 the following should work
    NetworkResponse response = error.networkResponse;
    if (error instanceof ServerError && response != null) {
        try {
            String res = new String(response.data,
                       HttpHeaderParser.parseCharset(response.headers, "utf-8"));
            // Now you can use any deserializer to make sense of data
            JSONObject obj = new JSONObject(res);
        } catch (UnsupportedEncodingException e1) {
            // Couldn't properly decode data to string
            e1.printStackTrace();
        } catch (JSONException e2) {
            // returned data is not JSONObject?
            e2.printStackTrace();
        }
    }
  }

4.You need to override getBodyContentType() and return application/x-www-form-urlencoded; charset=UTF-8.

StringRequest jsonObjRequest = new StringRequest(

    Request.Method.POST,
    getResources().getString(R.string.base_url),
    new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {

            MyFunctions.toastShort(LoginActivity.this, response);
        }
    }, 
    new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d("volley", "Error: " + error.getMessage());
            error.printStackTrace();
            MyFunctions.croutonAlert(LoginActivity.this,
                MyFunctions.parseVolleyError(error));
            loading.setVisibility(View.GONE);
        }
    }) {

    @Override
    public String getBodyContentType() {
        return "application/x-www-form-urlencoded; charset=UTF-8";
    }

    @Override
    protected Map<String, String> getParams() throws AuthFailureError {
        Map<String, String> params = new HashMap<String, String>();
        params.put("username", etUname.getText().toString().trim());
        params.put("password", etPass.getText().toString().trim());
        return params;
    }

};

AppController.getInstance().addToRequestQueue(jsonObjRequest);