jsonObjectRequest = new JsonObjectRequest( Request.Method.GET, url, ecplain
public class VolleyErrorHelper {
/**
* Returns appropriate message which is to be displayed to the user
* against the specified error object.
*
* @param error
* @param context
* @return
*/
public static String getMessage(Object error, Context context) {
if (error instanceof TimeoutError) {
return context.getResources().getString(R.string.generic_server_down);
}
else if (isServerProblem(error)) {
return handleServerError(error, context);
}
else if (isNetworkProblem(error)) {
return context.getResources().getString(R.string.no_internet);
}
return context.getResources().getString(R.string.generic_error);
}
/**
* Determines whether the error is related to network
* @param error
* @return
*/
private static boolean isNetworkProblem(Object error) {
return (error instanceof NetworkError) || (error instanceof NoConnectionError);
}
/**
* Determines whether the error is related to server
* @param error
* @return
*/
private static boolean isServerProblem(Object error) {
return (error instanceof ServerError) || (error instanceof AuthFailureError);
}
/**
* Handles the server error, tries to determine whether to show a stock message or to
* show a message retrieved from the server.
*
* @param err
* @param context
* @return
*/
private static String handleServerError(Object err, Context context) {
VolleyError error = (VolleyError) err;
NetworkResponse response = error.networkResponse;
if (response != null) {
switch (response.statusCode) {
case 404:
case 422:
case 401:
try {
// server might return error like this { "error": "Some error occured" }
// Use "Gson" to parse the result
HashMap<String, String> result = new Gson().fromJson(new String(response.data),
new TypeToken<Map<String, String>>() {
}.getType());
if (result != null && result.containsKey("error")) {
return result.get("error");
}
} catch (Exception e) {
e.printStackTrace();
}
// invalid request
return error.getMessage();
default:
return context.getResources().getString(R.string.generic_server_down);
}
}
return context.getResources().getString(R.string.generic_error);
}
}
// http client instance
private DefaultHttpClient mHttpClient;
public RequestQueue getRequestQueue() {
// lazy initialize the request queue, the queue instance will be
// created when it is accessed for the first time
if (mRequestQueue == null) {
// Create an instance of the Http client.
// We need this in order to access the cookie store
mHttpClient = new DefaultHttpClient();
// create the request queue
mRequestQueue = Volley.newRequestQueue(this, new HttpClientStack(mHttpClient));
}
return mRequestQueue;
}
/**
* Method to set a cookie
*/
public void setCookie() {
CookieStore cs = mHttpClient.getCookieStore();
// create a cookie
cs.addCookie(new BasicClientCookie2("cookie", "spooky"));
}
// add the cookie before adding the request to the queue
setCookie();
// add the request to the queue
mRequestQueue.add(request);
JsonObjectRequest req = new JsonObjectRequest(URL, new JSONObject(params),
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
// handle response
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// handle error
}
}) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
headers.put("CUSTOM_HEADER", "Yahoo");
headers.put("ANOTHER_CUSTOM_HEADER", "Google");
return headers;
}
};
StringRequest myReq = new StringRequest(Method.POST,
"http://somesite.com/some_endpoint.php",
createMyReqSuccessListener(),
createMyReqErrorListener()) {
protected Map<String, String> getParams() throws com.android.volley.AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("param1", num1);
params.put("param2", num2);
return params;
};
};
queue.add(myReq);