Android authentication using JSON

Question

I have a Python/Django server that is the API for a web service.
I'm building an Android application that will communicate with the API and authenticate users, and enable them do all pulls/pushes from the server.

My trouble is with the particular communication with the server. Currently I use my WiFi network, and run the server like so python manage.py runserver 192.168.1.3:8000 so that it is available to any test device on my LAN.

The API is written so it returns http status messages with every response, so that I can tell the success or failure of a request before parsing the JSON reply.

On my Android side, I have used HttpURLConnection because it has the getHeaderField(null) method that I use to pick the http status message from the response. I get a status message 200 [success] when I 'ping' my server - this is a sort-of proof of concept.

My real issue is authentication. My API requires I send it a JSON with data, and it returns a JSON response [with an http status message in the head].
I can't seem to figure out how to do this. The JSON action I've seen around the interwebs are merely picking, or posting.
I am wondering how I can POST and pick up a response from the server.

Extra information
- Server supports HEAD and GET and OPTIONS.
- Assuming server home is 192.168.1.3, user login/register would be in 192.168.1.3/user, events would be in 192.168.1.3/events and so on..
- This was the closest I got to figuring out a solution, but not quite..

CODE from the AsyncTask

protected JSONObject doInBackground(String... params)  {
publishProgress(true);

/*Create a new HttpClient and Post Header*/
JSONObject result=null;
HttpClient httpclient = new DefaultHttpClient();
try {

    URL url = new URL(cons.PROTOCOL,cons.SERVER,cons.PORT,"/user");
HttpPost httppost = new HttpPost(url.toURI());
HttpResponse response =null;

    /*Add your data*/
JSONObject j1=new JSONObject();
JSONObject json=new JSONObject();
j1.put("username", "test");
j1.put("email","test@test.com");
j1.put("password","password");
j1.put("first_name","John");
j1.put("last_name","Doe");
json.put("user",j1);
json.put("mobile_number","256774622240");
StringEntity se = new StringEntity( json.toString());  
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
httppost.setEntity(se);

    /*Execute HTTP Post Request*/
    response= httpclient.execute(httppost);

        Log.i("jazz","It's ALIVE!!!!!");
        Log.i("jazz",response.getStatusLine().toString());

} catch (ClientProtocolException e) {
    /* TODO Auto-generated catch block*/
} catch (IOException e) {
    // TODO Auto-generated catch block
} catch (URISyntaxException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}



return result;
}

Answer 1

If your are building your HttpPostRequest well, and you only want to know how to attach JSON, here you are a possible solution for it:

  StringEntity formEntity = new StringEntity(yourJsonObject.toString());
  yourPostRequest.setEntity(formEntity);

I hope this helps!

PS:In addition, let me recommend you the use of this component:

https://github.com/matessoftwaresolutions/AndroidHttpRestService

I've used it in an Android app that is connecting to a python server API and it makes http request easier for your Android client.

Answer 2

Okay, so I'm now answering my own question :D

The issue was with the path variable in the URL string .
This is the format of one of the URL constructors based on this document .
URL(String protocol, String host, int port, String file)

Since I am posting the JSON to the /user path, that's the one I insert into the constructor as the directory.
So, my URL was formed like so:
URL url= new URL("http",cons.SERVER,cons.PORT,"/user/");

My mistake in the beginning was using /user instead of /user/ but other than that, the URL structure and connections are all alright.