Http Status Code in Android Volley when error.networkResponse is null

Question

I am using Google Volley on the Android platform. I am having a problem in which the error parameter in onErrorResponse is returning a null n

Answer 1

You may modify the volley library's performRequest me(toolbox/BasicNetwork.java) method to capture 401 Unauthorized response. (This modified code will also solve http-> https redirect problem of volley)

 @Override
public NetworkResponse performRequest(Request<?> request) throws VolleyError {
    long requestStart = SystemClock.elapsedRealtime();
    while (true) {
        HttpResponse httpResponse = null;
        byte[] responseContents = null;
        Map<String, String> responseHeaders = Collections.emptyMap();
        try {
            // Gather headers.
            Map<String, String> headers = new HashMap<String, String>();
            addCacheHeaders(headers, request.getCacheEntry());
            httpResponse = mHttpStack.performRequest(request, headers);
            StatusLine statusLine = httpResponse.getStatusLine();
            int statusCode = statusLine.getStatusCode();

            responseHeaders = convertHeaders(httpResponse.getAllHeaders());
            // Handle cache validation.
            if (statusCode == HttpStatus.SC_NOT_MODIFIED) {

                Entry entry = request.getCacheEntry();
                if (entry == null) {
                    return new NetworkResponse(HttpStatus.SC_NOT_MODIFIED, null,
                            responseHeaders, true,
                            SystemClock.elapsedRealtime() - requestStart);
                }

                // A HTTP 304 response does not have all header fields. We
                // have to use the header fields from the cache entry plus
                // the new ones from the response.
                // http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5
                entry.responseHeaders.putAll(responseHeaders);
                return new NetworkResponse(HttpStatus.SC_NOT_MODIFIED, entry.data,
                        entry.responseHeaders, true,
                        SystemClock.elapsedRealtime() - requestStart);
            }

            // Handle moved resources
            if (statusCode == HttpStatus.SC_MOVED_PERMANENTLY || statusCode == HttpStatus.SC_MOVED_TEMPORARILY) {
                String newUrl = responseHeaders.get("Location");
                request.setUrl(newUrl);
            }



            // Some responses such as 204s do not have content.  We must check.
            if (httpResponse.getEntity() != null) {
                responseContents = entityToBytes(httpResponse.getEntity());
            } else {
                // Add 0 byte response as a way of honestly representing a
                // no-content request.
                responseContents = new byte[0];
            }

            // if the request is slow, log it.
            long requestLifetime = SystemClock.elapsedRealtime() - requestStart;
            logSlowRequests(requestLifetime, request, responseContents, statusLine);

            if (statusCode < 200 || statusCode > 299) {
                throw new IOException();
            }
            return new NetworkResponse(statusCode, responseContents, responseHeaders, false,
                    SystemClock.elapsedRealtime() - requestStart);
        } catch (SocketTimeoutException e) {
            attemptRetryOnException("socket", request, new TimeoutError());
        } catch (ConnectTimeoutException e) {
            attemptRetryOnException("connection", request, new TimeoutError());
        } catch (MalformedURLException e) {
            throw new RuntimeException("Bad URL " + request.getUrl(), e);
        } catch (IOException e) {
            int statusCode = 0;
            NetworkResponse networkResponse = null;
            if (httpResponse != null) {
                statusCode = httpResponse.getStatusLine().getStatusCode();
            } else {
                throw new NoConnectionError(e);
            }
            if (statusCode == HttpStatus.SC_MOVED_PERMANENTLY ||
                    statusCode == HttpStatus.SC_MOVED_TEMPORARILY) {
                VolleyLog.e("Request at %s has been redirected to %s", request.getUrl(), request.getUrl());
            } else {
                VolleyLog.e("Unexpected response code %d for %s", statusCode, request.getUrl());
                if (statusCode==HttpStatus.SC_FORBIDDEN) {
                    throw new VolleyError("403");
                }else if (statusCode == HttpStatus.SC_UNAUTHORIZED) {
                    attemptRetryOnException("auth",
                            request, new AuthFailureError(""));
                }
            }
            if (responseContents != null) {
                networkResponse = new NetworkResponse(statusCode, responseContents,
                        responseHeaders, false, SystemClock.elapsedRealtime() - requestStart);
                if (statusCode == HttpStatus.SC_UNAUTHORIZED) {
                    attemptRetryOnException("auth",
                            request, new AuthFailureError(networkResponse));
                } else if (statusCode == HttpStatus.SC_MOVED_PERMANENTLY ||
                        statusCode == HttpStatus.SC_MOVED_TEMPORARILY) {
                    attemptRetryOnException("redirect",
                            request, new AuthFailureError(networkResponse));
                } else {
                    // TODO: Only throw ServerError for 5xx status codes.
                    throw new ServerError(networkResponse);
                }
            } else {
                throw new NetworkError(e);
            }
        }
    }
}

then in volley error handler use this code

@Override
        public void onErrorResponse(VolleyError error) {
             if (error instanceof AuthFailureError) {
                //handler error 401 unauthorized from here
            }
        }
    })

Happy coding :D

Answer 2

Network response can be received in the following format

NetworkResponse response = error.networkResponse;
                if(response != null && response.data != null){
                    switch(response.statusCode){
                        case 403:
                            json = new String(response.data);
                            json = trimMessage(json, "error");
                            if(json != null) displayMessage(json);
                            break;
                    }
                }