NodeMCU server bad response, when sending GET request from Android app - android

I've made little server based on NodeMCU. All works good, when I'm conneting from browser, but problem starts, when I'm trying to connect from Android app uisng OkHttp or Volley, I'm receiving exceptions.
java.io.IOException: unexpected end of stream on Connection using OkHttp,
EOFException using Volley.
Problem is very similar for this
EOFException after server responds, but answer didn't found.
ESP server code
srv:listen(80, function(conn)
conn:on("receive", function(conn,payload)
print(payload)
conn:send("<h1> Hello, NodeMCU.</h1>")
end)
conn:on("sent", function(conn) conn:close() end)
end)
Android code
final RequestQueue queue = Volley.newRequestQueue(this);
final String url = "http://10.42.0.17:80";
final StringRequest request = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
mTemperatureTextView.setText(response.substring(0, 20));
System.out.println(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
System.out.println("Error + " + error.toString());
mTemperatureTextView.setText("That didn't work!");
}
}
);
mUpdateButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
queue.add(request);
}
});

What you're sending back is not HTTP. It's nothing but a protocol-agnostic HTML fragment. Furthermore, there's a memory leak lingering.
Try this instead:
srv:listen(80, function(conn)
conn:on("receive", function(sck,payload)
print(payload)
sck:send("HTTP/1.0 200 OK\r\nServer: NodeMCU on ESP8266\r\nContent-Type: text/html\r\n\r\n<h1> Hello, NodeMCU.</h1>")
end)
conn:on("sent", function(sck) sck:close() end)
end)
you need to send back some HTTP headers, HTTP/1.0 200 OK and the newlines are mandatory
each function needs to use it's own copy of the passed socket instance, see how I renamed conn to sck in the two callback functions, see https://stackoverflow.com/a/37379426/131929 for details
For a more complete send example look at net.socket:send() in the docs. That becomes relevant once you start sending more than just a couple of bytes.

Related

Android and REST service call - code review

I have asked a similar question but the answer did not help me. I am trying to call a rest service from my android app. The rest service looks like this:
#RestController
#RequestMapping("/login")
public class LoginController {
#ResponseBody
#RequestMapping(value = "/user", method = RequestMethod.GET)
public boolean getUser(#RequestParam(value = "name", required = true) String userName, #RequestParam(value = "password", required = true) String password) {
if (userName.equals("MMM") && password.equals("mmm")) {
return true;
} else {
return false;
}
}
}
I start my REST service and I try to call it from my android app like this:
public void invokeWS(RequestParams params){
AsyncHttpClient client = new AsyncHttpClient();
client.setConnectTimeout(7000);
client.get("https://ipaddress:8080/login/user/",params ,new AsyncHttpResponseHandler() {
#Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
// Hide Progress Dialog
prgDialog.hide();
try {
JSONObject obj = new JSONObject(responseBody.toString());
if(obj.getBoolean("status")){
Toast.makeText(getApplicationContext(), "You are successfully logged in!", Toast.LENGTH_LONG).show();
// Navigate to Home screen
navigatetoHomeActivity();
}
// Else display error message
else{
errorMsg.setText(obj.getString("error_msg"));
Toast.makeText(getApplicationContext(), obj.getString("error_msg"), Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
Toast.makeText(getApplicationContext(), "Error Occured [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
#Override
public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
prgDialog.hide();
if(statusCode == 404){
Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
}
else if(statusCode == 500){
Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
}
// When Http response code other than 404, 500
else{
Toast.makeText(getApplicationContext(), statusCode + "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet or remote server is not up and running]", Toast.LENGTH_LONG).show();
// Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet or remote server is not up and running]", Toast.LENGTH_LONG).show();
}
}
});
}
The status code that I receive is 0.
When I use an API to test the REST service it is OK. I do not get any errors. I am on the same network and the firewall is turned off.
To understand what is going wrong you need to investigate in your "error" object in onFailure method
#Override
public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
Log.i("ws", "---->>onFailure : " + error);
}
});
SUGGESTIONS:
1) Do not send password in GET!
The password must not be part of the url, please use POST and send the password in the request body
2) Your android code looks good, but it exist a native framework to call REST services called "VOLLEY"
Volley offers the following benefits:
Automatic scheduling of network requests.
Multiple concurrent network connections.
Transparent disk and memory response caching with standard HTTP cache coherence.
Support for request prioritization.
Cancellation request API. You can cancel a single request, or you can set blocks or scopes of requests to cancel.
Ease of customization, for example, for retry and backoff.
Strong ordering that makes it easy to correctly populate your UI with data fetched asynchronously from the network.
Debugging and tracing tools.
the code is not more complex than yours...
EXAMPLE:
String url = "http://my-json-feed";
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest
(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
mTextView.setText("Response: " + response.toString());
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
// TODO: Handle error
}
});
https://developer.android.com/training/volley/
I can see you are doing a couple of "bad practices" here.
Problem 1
I can see your Spring Controller is wanting a Username and Password as URL parameters. This is a no. A server may log URL/endpoint requests which will now contain your credentials in plain text.
Fix option
Very common -> Use an Authorization header (most common: See Basic Auth) over HTTPS.
Less common -> Pass the username and password in a POST body.
Problem 2
Not using the framework as intended
I'd suggest using Spring Security. It will make your stuff a lot more secure and worth doing in the long run. It will take care of authentication, roles and password hashing all for you.

Android Volley Error Null using Stored Procedures in EF

Im consuming a RESTful Api builded with ASP EF. I have a procedure in my DB, this is it:
ALTER PROCEDURE [Ventas].[CtasxCobxVendedor]
#AGE CHAR(1),
#VENDEDOR VARCHAR(10)
AS
BEGIN
SET NOCOUNT ON
SELECT
V.CLIENTE Codigo,
C.RazonSocialAnalitico Cliente,
C.DireccionAnalitico Direccion,
C.TelefonoAnalitico Telefono,
V.Gestion,
V.IdDos,
V.DCTO,
V.Factura,
V.Fecha,
V.Vencimiento,
SUM(B.DBB) Monto,
SUM(B.HBB) Pagos,
SUM(B.DBB-B.HBB) Saldo
FROM VENTAS.VMAESTRO V
JOIN VENTAS.CTASXCOBRAR B ON
(V.GESTION=B.GESTIONF
AND V.AGE =B.AGE
AND V.TIPO = B.TIPOF
AND V.IDDOS = B.IDDOSF
AND V.DCTO = B.DCTOF)
JOIN VENTAS.vwCLIENTES C ON
(V.CLIENTE = C.IdAnalitico)
WHERE
-- V.AGE =#AGE
V.STA = 'A'
AND V.VENDEDOR = #VENDEDOR
GROUP BY V.CLIENTE,C.RazonSocialAnalitico,C.DireccionAnalitico,C.TELEFONOAnalitico,V.Gestion,V.IdDos,V.DCTO,V.Factura,V.FECHA,V.VENCIMIENTO
HAVING SUM(B.DBB-B.HBB) > 0.001
ORDER BY C.RazonSocialAnalitico, V.FECHA, V.DCTO;
RETURN 0;
END
I created the import function, and the Complex Type on VS. So this is what I got:
public virtual ObjectResult<CtasxCobxVendedor_Result> CtasxCobrarV(string aGE, string vENDEDOR)
{
var aGEParameter = aGE != null ?
new ObjectParameter("AGE", aGE) :
new ObjectParameter("AGE", typeof(string));
var vENDEDORParameter = vENDEDOR != null ?
new ObjectParameter("VENDEDOR", vENDEDOR) :
new ObjectParameter("VENDEDOR", typeof(string));
return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<CtasxCobxVendedor_Result>("CtasxCobrarV", aGEParameter, vENDEDORParameter);
}
Then I tried to call this SP in one of my controllers, in this case is my Personal controller, like this:
public IQueryable<CtasxCobxVendedor_Result1> GetCuenta(string id)
{
using (NemesisEntities ctx = new NemesisEntities()) {
return db.CtasxCobxVendedor("A", id).AsQueryable();
}
}
When I call this method on the browser (like this "localhost:45896/api/personals/3329672" where "3329672" is the Personal Id) works just fine, cause it gives me this result:
[{"Codigo":"1018389023","Cliente":"BAREMSA","Direccion":"Av. Cicunvalación - ITOS S/N","Telefono":"","Gestion":"15","IdDos":503,"DCTO":15001980,"Factura":1097,"Fecha":"2015-10-21T00:00:00","Vencimiento":"2015-11-20T00:00:00","Monto":1380.0000,"Pagos":0.0000,"Saldo":1380.0000},{"Codigo":"1018389023","Cliente":"BAREMSA","Direccion":"Av. Cicunvalación - ITOS S/N","Telefono":"","Gestion":"15","IdDos":509,"DCTO":15002329,"Factura":128,"Fecha":"2015-12-09T00:00:00","Vencimiento":"2016-01-08T00:00:00","Monto":1980.0000,"Pagos":0.0000,"Saldo":1980.0000},{"Codigo":"3095060012","Cliente":"BERTHA CONDORI ORURO","Direccion":"","Telefono":" 25288136","Gestion":"15","IdDos":509,"DCTO":15002349,"Factura":148,"Fecha":"2015-12-11T00:00:00","Vencimiento":"2016-01-10T00:00:00","Monto":1450.0000,"Pagos":0.0000,"Saldo":1450.0000},{"Codigo":"1015777022","Cliente":"CADEXNOR","Direccion":"","Telefono":"","Gestion":"16","IdDos":509,"DCTO":16000384,"Factura":661,"Fecha":"2016-03-09T00:00:00","Vencimiento":"2016-04-08T00:00:00","Monto":1440.0000,"Pagos":0.0000,"Saldo":1440.0000},{"Codigo":"1006965023","Cliente":"COMIBOL","Direccion":"Plaza 6 de Agosto","Telefono":" 68224768","Gestion":"14","IdDos":10,"DCTO":14000142,"Factura":314,"Fecha":"2012-08-03T00:00:00","Vencimiento":"2012-08-08T00:00:00","Monto":2770.0000,"Pagos":0.0000,"Saldo":2770.0000},{"Codigo":"1006965023","Cliente":"COMIBOL","Direccion":"Plaza 6 de Agosto","Telefono":" 68224768","Gestion":"14","IdDos":10,"DCTO":14000143,"Factura":776,"Fecha":"2013-10-03T00:00:00","Vencimiento":"2013-11-02T00:00:00","Monto":2900.0000,"Pagos":0.0000,"Saldo":2900.0000}]
Then when I try to connect it to my Android app using Volley framework:
JsonArrayRequest re= new JsonArrayRequest(Request.Method.GET, newURL, (String)null, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Toast.makeText(Cobrar.this,response.toString(),Toast.LENGTH_LONG).show();
procesarRespuesta(response);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(Cobrar.this,"NOTHING",Toast.LENGTH_LONG).show();
Log.d(TAG, "Error Volley: " + error.getMessage());
}
});
Where "newURL" is like the one above. Just Give me "Error Volley:null" without any other explanation.
I really dont know what to fix, cause when I use simple GET calls for example calling this: "http://localhost:45896/api/clientes", it works fine, the problem is when I want to use the SP.
Any idea of what am I doind wrong? Since I dont get any information of where my problem actually is, Idk where to start
Please check this question posted here.
I have faced same issue.
Why this happens?
In volley, When timeout/socket timeout occurs it throws error. but
error object is null. You can override two methods in your Request
class to check if its timeout.
Solution :
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST, "url", "request", new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
}) {
#Override
protected void deliverResponse(JSONObject response) {
super.deliverResponse(response);
}
#Override
public void deliverError(VolleyError error) {
super.deliverError(error);
}
};
You can get error on deliverError method in above code.
TimeOut occurs when server takes more time to respond to app then defined in RetryPolicy.
request.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 48,
0, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
default timeout is 2500 seconds for Volley.
You can avoid this issue using following improvements :
You need to improve your server performance
You can set retryCount to 1 if it suits your app requirements.
Thanks.

How to wait for RequestQueue job to finish?

I'm trying to create a login page for my app. I check the credentials by doing a get request to a web server which is tied in to my user database.
public boolean checkCredentials(String email, String password) throws JSONException {
// Make a get request to the server
String url = MyUtils.createLoginUrl(email, password);
JsonObjectRequest jsObjRequest = new JsonObjectRequest
(Request.Method.GET, url, requestParam, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
successLogin = response.length() > 0;
jsonResponse = response.length() > 0 ? response : null;
//requestPending -= 1;
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
MyUtils.showToast(getBaseContext(), error.getMessage().toString());
//requestPending -= 1;
}
});
SingletonRequestQueue.getInstance(this).addToRequestQueue(jsObjRequest);
//requestPending += 1;
// I WANT THE JOB TO FINISH BEFORE RETURNING FROM THIS FUNCTION
return successLogin;
}
Is there a non-blocking way to do this using the Volley library? Google wasn't giving me much info.
You can't with Volley and you shoudn't with other tools. Long running operations like going to database or to network block the UI thread which is a bad practice since the user can't interact to the UI.
Talking about volley, it does all this job asynchronous in three thread levels:
UI
Cache
Network
See here the schema.
All three levels allows the system to cache the responses and use a pool thread to dispatch all the requests at the same time if enough space and memory.
Some time ago people recommended you to do:
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
This avoided the NetworkOnMainThreadException, but as I told you before it is a really bad practice because you will be skipping a bunch of frames by waiting.
I know listeners are a pain, but all we have to live with them in Android Dev.

Arabic text did not show Json Android when using 3g

when I use this link to get date and day in Arabic language (utf-8)
http://iraqispring.com/apps/get_date_time.php
it is work without problems when I use wifi
but when I use 3g it is get me like this text
الاثنين 2015-01-12
I am using Volley library and this is the code
RequestQueue queuedate = Volley.newRequestQueue(this);
String url ="http://iraqispring.com/apps/get_date_time.php";
StringRequest stringRequestDate = new StringRequest(Request.Method.GET, url,
new Response.Listener() {
#Override
public void onResponse(Object o) {
String dateStr = o.toString();
dateStr.getBytes();
txtDate.setText(dateStr);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(context,"not worked 3",Toast.LENGTH_LONG).show();
}
});
what can I do?
While sending such kind of special characters to server you need to encode such input with the help of URLEncoder.encode(your_input, "utf-8") and while receiving such kind of data first of all you need to decode it with the help of URLDecoder.decode(your_data, "utf-8")
I have also faced such kind of problem, so I followed encoding and decoding and resolved the problem.
I think this will help you too.

Android volley to handle redirect

I recently started to use Volley lib from Google for my network requests. One of my requests get error 301 for redirect, so my question is that can volley handle redirect somehow automatically or do I have to handle it manually in parseNetworkError or use some kind of RetryPolicyhere?
Thanks.
Replace your url like that url.replace("http", "https");
for example:
if your url looking like that : "http://graph.facebook......." than
it should be like : "https://graph.facebook......."
it works for me
I fixed it catching the http status 301 or 302, reading redirect url and setting it to request then throwing expection which triggers retry.
Edit: Here are the main keys in volley lib which i modified:
Added method public void setUrl(final String url) for class Request
In class BasicNetwork is added check for redirection after // Handle cache validation, if (statusCode == HttpStatus.SC_MOVED_PERMANENTLY) || statusCode == HttpStatus.SC_MOVED_TEMPORARILY), there I read the redirect url with responseHeaders.get("location"), call setUrl with request object and throw error
Error get's catched and it calls attemptRetryOnException
You also need to have RetryPolicy set for the Request (see DefaultRetryPolicy for this)
If you dont want to modify the Volley lib you can catch the 301 and manually re-send the request.
In your GsonRequest class implement deliverError and create a new Request object with the new Location url from the header and insert that to the request queue.
Something like this:
#Override
public void deliverError(final VolleyError error) {
Log.d(TAG, "deliverError");
final int status = error.networkResponse.statusCode;
// Handle 30x
if(HttpURLConnection.HTTP_MOVED_PERM == status || status == HttpURLConnection.HTTP_MOVED_TEMP || status == HttpURLConnection.HTTP_SEE_OTHER) {
final String location = error.networkResponse.headers.get("Location");
Log.d(TAG, "Location: " + location);
final GsonRequest<T> request = new GsonRequest<T>(method, location, jsonRequest, this.requestContentType, this.clazz, this.ttl, this.listener, this.errorListener);
// Construct a request clone and change the url to redirect location.
RequestManager.getRequestQueue().add(request);
}
}
This way you can keep updating Volley and not have to worry about things breaking.
Like many others, I was simply confused about why Volley wasn't following redirects automatically. By looking at the source code I found that while Volley will set the redirect URL correctly on its own, it won't actually follow it unless the request's retry policy specifies to "retry" at least once. Inexplicably, the default retry policy sets maxNumRetries to 0. So the fix is to set a retry policy with 1 retry (10s timeout and 1x back-off copied from default):
request.setRetryPolicy(new DefaultRetryPolicy(10000, 1, 1.0f))
For reference, here is the source code:
/**
* Constructs a new retry policy.
* #param initialTimeoutMs The initial timeout for the policy.
* #param maxNumRetries The maximum number of retries.
* #param backoffMultiplier Backoff multiplier for the policy.
*/
public DefaultRetryPolicy(int initialTimeoutMs, int maxNumRetries, float backoffMultiplier) {
mCurrentTimeoutMs = initialTimeoutMs;
mMaxNumRetries = maxNumRetries;
mBackoffMultiplier = backoffMultiplier;
}
Alternatively, you can create a custom implementation of RetryPolicy that only "retries" in the event of a 301 or 302.
Hope this helps someone!
End up doing a merge of what most #niko and #slott answered:
// Request impl class
// ...
#Override
public void deliverError(VolleyError error) {
super.deliverError(error);
Log.e(TAG, error.getMessage(), error);
final int status = error.networkResponse.statusCode;
// Handle 30x
if (status == HttpURLConnection.HTTP_MOVED_PERM ||
status == HttpURLConnection.HTTP_MOVED_TEMP ||
status == HttpURLConnection.HTTP_SEE_OTHER) {
final String location = error.networkResponse.headers.get("Location");
if (BuildConfig.DEBUG) {
Log.d(TAG, "Location: " + location);
}
// TODO: create new request with new location
// TODO: enqueue new request
}
}
#Override
public String getUrl() {
String url = super.getUrl();
if (!url.startsWith("http://") && !url.startsWith("https://")) {
url = "http://" + url; // use http by default
}
return url;
}
It worked well overriding StringRequest methods.
Hope it can help someone.
Volley supports redirection without any patches, no need for a separate fork
Explanation:
Volley internally uses HttpClient which by default follows 301/302 unless specified otherwise
From: http://hc.apache.org/httpcomponents-client-4.2.x/tutorial/html/httpagent.html
ClientPNames.HANDLE_REDIRECTS='http.protocol.handle-redirects': defines whether redirects should be handled automatically. This parameter expects a value of type java.lang.Boolean. If this parameter is not set HttpClient will handle redirects automatically.
ok, im a bit late to the game here, but i've recently been trying to achieve this same aspect, so https://stackoverflow.com/a/17483037/2423312 is the best one, given that you are willing to fork volley and maintain it and the answer here : https://stackoverflow.com/a/27566737/2423312 - I'm not sure how this even worked.This one is spot on though : https://stackoverflow.com/a/28454312/2423312. But its actually adding a new request object to the NetworkDipatcher's queue, so you'll have to notify the caller as well somehow, there is one dirty way where you can do this by not modifying the request object + changing the field "mURL", PLEASE NOTE THAT THIS IS DEPENDENT ON YOUR IMPLEMENTATION OF VOLLEY'S RetryPolicy.java INTERFACE AND HOW YOUR CLASSES EXTENDING Request.java CLASS ARE, here you go : welcome REFLECTION
Class volleyRequestClass = request.getClass().getSuperclass();
Field urlField = volleyRequestClass.getDeclaredField("mUrl");
urlField.setAccessible(true);
urlField.set(request, newRedirectURL);
Personally I'd prefer cloning volley though. Plus looks like volley's example BasicNetwork class was designed to fail at redirects : https://github.com/google/volley/blob/ddfb86659df59e7293df9277da216d73c34aa800/src/test/java/com/android/volley/toolbox/BasicNetworkTest.java#L156 so i guess they arent leaning too much on redirects, feel free to suggest/edit. Always looking for good way..
I am using volley:1.1.1 with https url though the request was having some issue. On digging deeper i found that my request method was getting changed from POST to GET due to redirect (permanent redirect 301). I am using using nginx and in server block i was having a rewrite rule that was causing the issue.
So in short everything seems good with latest version of volley. My utility function here-
public void makePostRequest(String url, JSONObject body, final AjaxCallback ajaxCallback) {
try {
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST,
url, body, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
Log.d(LOG, response.toString());
ajaxCallback.onSuccess(response);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(LOG, error.toString());
ajaxCallback.onError(error);
}
});
singleton.getRequestQueue().add(jsonObjectRequest);
} catch(Exception e) {
Log.d(LOG, "Exception makePostRequest");
e.printStackTrace();
}
}
// separate file
public interface AjaxCallback {
void onSuccess(JSONObject response);
void onError(VolleyError error);
}

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