Android HTTP Post request problem - android

I'm working on an issue which is:
+ I send a HTTP POST request to a server and get the response.
+ I use a DefaultHTTPClient instance to send the request. And I use BasicNameValuePair to add the params for the server to process.
There is a param which is a xml-based string. The problem is that, when I send an "empty" string like this: " ", the server response "SUCCESSFUL". But when I send another value which is much longer. The server response "UNSUCCESSFUL" due to this parameter.
Please tell me that whether Android has a max length limitation on BasicNameValue instance or not? And how can I fix this issue.
Thanks in advance.

I expect the problem is with your web service, not with the BasicNameValue implementation on Android: you are probably just sending it a bad parameter. Do you get SUCCESSFUL when you send the exact same request parameters from another programming language?

Related

Android Calling Django Server With POST Data

someone may asked my question already but I cannot find any suggestions.
I writing an Android app which needs to access my Django server by using HttpsURLConnection then Django server will return a JSON array to Android.
The view function in Django will receive the parameters from request.POST and generate the JSON array then return using HTTPResponse Django method. It does not need any Templates and Forms.
When I call the Django view function from Android, it returns 403 error. I know that it is because the POST data does not contains "csrf_token".
My problem is: How can I get the "csrf_token" and put it into my POST data before I send it to Django? I try disable the CSRF checking by "#csrf_exempt" it can return the correct result to Android app but I would not disable the CSRF checking.
Thanks,
Wilson
You have to send the cookies and also have to send a header 'X-CSRFToken' with csrftoken.
This is what I do (may not be the best way):
Get csrf token via a get request.But first try to see if you get a csrftoken cookie by doing same request on your browser with developer tools. If not, you should use ensure_csrf_cookie decorator
from django.views.decorators.csrf import ensure_csrf_cookie
#ensure_csrf_cookie
def your_view(request):
pass
Now using the same HttpUrlConnection object do this :
String cookieString="";
String csrftoken="";
// The below code can be shortened using for-each loop
List<HttpCookie> cookies=cookieManager.getCookieStore().getCookies();
Iterator<HttpCookie> cookieIterator=cookies.iterator();
while(cookieIterator.hasNext()){
HttpCookie cookie=cookieIterator.next();
cookieString+=cookie.getName()+"="+cookie.getValue()+";";
if(cookie.getName().equals("csrftoken")){
csrftoken=cookie.getValue();
}
}
Add the following to your post request:
urlConnection.setRequestProperty("X-CSRFToken", csrftoken);
urlConnection.setRequestProperty("Cookie", cookieString);

Authenticating a file stream from android to wcf

I have an app that makes request to a wcf service. Usually I authenticate all of the requests using a hash value that is sent in the body of the request and then authenticated on the server. All most all of the request are sent via json and it is easy for me to add the hash value to the body of the request. The issue I am facing is that when I send a file stream I cannot add the hash to the body of the request so I am wondering how I can authenticate that the request came from my app and not from some where else. All suggestions are greatly appreciated.
Adding an authorization item in the header is a possible solution. So, if anyone is interested, read this and this.

HTTP GET url with Json parameters in Android

I am having the following API call:
http://rollout.gr/api/?query={%22search%22:%22places%22,%22page%22:1}
This API call is executed correctly in my browser. But when I use a DefaultHttpClient to execute this url in my Android application, I get a null response.
I suppose the problem is the JSON data in the HTTP url. Thus, I would like to ask which is the proper way to handle such url in an Android application?
Thanks a lot in advance!
The accolades aren't valid URL characters. The browser is userfriendly enough to automatically URL-encode them, but DefaultHttpClient isn't. The correct line to use from code is:
http://rollout.gr/api/?query=http://rollout.gr/api/?query=%7b%22search%22:%22places%22,%22page%22:1%7d
Note the encoding for the accolades (%7b, %7d).
Your problem may be the strictmode here.
I recommend to do http request in threads or asynctasks. strictmode doesnt let app do http reauest in uithread. maybe your console shows a warning and you get null from http response because of this.
This project may solve your problem:
http://loopj.com/android-async-http/
Not knowing your particular HTTP initialization code, I'm going to assume you didn't provide an explicit JSON accept header. A lot of REST endpoints require this.
httpget.setHeader("Accept", "application/json");

Occasional SocketTimeoutException -- No "OK" message from server

I am currently using the DefaultHttpClient to create an HTTP request to a rails server.
The network call is failing about 4% of the time with a SocketTimeoutException.
I have run Wireshark on my network traffic and discovered the following:
My successful call starts like this
And ends like this
The failed call starts like this:
And ends like this
Please note that the HTTP OK message that is sent to us from the server is missing from the end call, resulting in it timing out after about 15 seconds.
I am wondering if anybody has encountered this before or has any recommendations for debugging the Android Apache library or Apache rails to figure out why we are not receiving the HTTP OK message from the server.
I figured this out. The rails server and apache library were timing out if there were bad parameters in my post request. We were passing in a "_b" parameter, and for some unknown reason the server wouldn't like this and would time out the request. Removing the bad post parameter fixed the problem.
If anybody else is seeing timeouts like this, I recommend reviewing the POST parameters that are being passed in.

HTTP Response 411 Length Required, Http Client 4.0.1 Android

i'm sending an http request to the google reader api and getting an unusual response code. following the documentation, i've requested an auth code and included it in the header of every request. after performing the login, and getting an auth code, i tried accessing this url, which is part of the documentation:
http://www.google.com/reader/api/0/stream/items/contents
when i send the request, i get a 411 status code, which is supposed to mean "Length Required". the length, as i've found, is supposed to be the length, in octets, of the message body. there is no message body in this request. there is only a single header, the POST parameter i="item id" and the URL itself. i tried setting the "Content-Length" header to "0" and also to "-1" to no avail.
what's really interesting is that this same code worked fine before google changed their authorization procedure. it's apparent they've changed something else...
so my question is what EXACTLY would cause a 411 response code and how can i prevent it?
This error happens only with POST and PUT request types, as these two (sort of) expect to have a request body that includes the request parameters (plain textual as well as attachments).
However as the documentation suggests, this is largely an obsolete value, and realistically the web services should handle requests without relying on Content-Length.
So it's not the problem of a request sender, but it is (I would say) a bug on the service side.
Nevertheless, setting a Content-Length (mind the proper capitalisation) request header to 0 should be the workaround.

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