Develop Reference

How can I pass data from my android application and receive it on my ASP.NET MVC website?

I want to send the some varibeles from my android application to my ASP.NET website, so I can use it there and I don't know how to do that.

If your ASP.NET application has some type of public API that would allow it to interact with external applications, you should be able to make a Web Request to it and post the appropriate values that you needed.
I'm not terribly familiar with Android syntax, but an example like this one on making HTTP GET/POST requests from Android should point you in the right direction :
// Build your client
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("your-asp-mvc-application/Home/AcceptData");
// Build a collection of data that you want to send
List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>(2);
nameValuePair.add(new BasicNameValuePair("username", "test_user"));
nameValuePair.add(new BasicNameValuePair("password", "123456789"));
// Encoding POST data
try
{
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
}
catch (UnsupportedEncodingException e) {
// log exception
e.printStackTrace();
}
// Make the request
try
{
HttpResponse response = httpClient.execute(httpPost);
// write response to log
Log.d("Http Post Response:", response.toString());
}
catch (ClientProtocolException e)
{
// Log exception
e.printStackTrace();
}
catch (IOException e)
{
// Log exception
e.printStackTrace();
}
Basically, once you make make requests, you should be able to target your application and create a Controller Action that can actually accept what you are sending it :
public ActionResult AcceptData(string username, string password)
{
// Do something here
}

First, what form of ASP.NET are you using - Forms or MVC? Also, what do you mean by "send?" Where exactly do you want the data to end up and what exactly do you want your ASP.NET application to do once it receives the data? If you simply mean that you're creating data in your phone and you want your ASP.NET web site to be able to access it too, you can just insert the data into a database that your ASP.NET web site also has access to (e.g. through a web service call or something like that).

Android authentication using JSON

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;
}

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.

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.

Sending JSON From Android to PHP

I've been struggling a bit on sending JSON objects from an application on android to a php file (hosted locally). The php bit is irrelevant to my issue as wireshark isn't recording any activity from my application (emulation in eclipse/ADK) and it's almost certainly to do with my method of sending:
try {
JSONObject json = new JSONObject();
json.put("id", "5");
json.put("time", "3:00");
json.put("date", "03.04.12");
HttpParams httpParams = new BasicHttpParams();
HttpClient client = new DefaultHttpClient(httpParams);
//
//String url = "http://10.0.2.2:8080/sample1/webservice2.php?" +
// "json={\"UserName\":1,\"FullName\":2}";
String url = "http://localhost/datarecieve.php";
HttpPost request = new HttpPost(url);
request.setEntity(new ByteArrayEntity(json.toString().getBytes(
"UTF8")));
request.setHeader("json", json.toString());
HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
// If the response does not enclose an entity, there is no need
if (entity != null) {
InputStream instream = entity.getContent();
}
} catch (Throwable t) {
Toast.makeText(this, "Request failed: " + t.toString(),
Toast.LENGTH_LONG).show();
}
I've modified this from an example I found, so I'm sure I've taken some perfectly good code and mangled it. I understand the requirement for multi-threading so my application doesn't hang and die, but am unsure about the implementation of it. Would using Asynctask fix this issue, or have I missed something else important?
Thankyou for any help you can provide.

Assuming that you are using emulator to test the code, localhost refers to the emulated environment. If you need to access the php hosted on your computer, you need to use the IP 10.0.2.2 or the LAN IP such as 192.168.1.3. Check Referring to localhost from the emulated environment
You can refer to Keeping Your App Responsive to learn about running your long running operations in an AsyncTask

you should use asynctask or thread, because in higher versions of android it doesn't allow long running task like network operations from ui thread.
here is the link for more description

How to perform syncing in android?

I am creating a networking website's Application in android.I want to know how can I perform syncing ie I want to store all user contacts on websites to my android phone.
user's details will come in XML format.
Please Guide me ..

For that you have to make a web service call either by using HttpClient or by using other third-party libraries like kSoap2. But i would prefer native class instead of third-party library.
Here is a best example: http://lukencode.com/2010/04/27/calling-web-services-in-android-using-httpclient/
After making a call, you will receive a XML, after that you can parse the received XML response either by using SAX parser, Pull Parser or DOM Parser.
This is the scenario to fetch data from web to your local database.
For your info: To get response from Web:
public static InputStream getInputStreamFromWeb(String url) {
InputStream content = null;
try {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(new HttpGet(url));
content = response.getEntity().getContent();
} catch (Exception e) {
Log.("GET", "Network exception", e);
}
return content;
}

How to improve my Rest Calls on Android?

I am making an app for Android. I like to make the rest calls as quick as possible. When I get my results as XML it takes 5 seconds (!) to get a simple xml like this:
<souvenirs>
<souvenir>
<id>1</id>
<name>Example 1</name>
<rating>3.4</rating>
<photourl>/images/example.jpg</photourl>
<price>3.50</price>
</souvenir>
<souvenir>
<id>2</id>
<name>Example 2</name>
<rating>2.4</rating>
<photourl>/images/example.jpg</photourl>
<price>8.50</price>
</souvenir>
</souvenirs>
So I tried it with JSON. But that takes also about 5 seconds to retrieve.
I load the XML in android with the following code:
URL url = new URL("http://example.nu?method=getAllSouvenirs");
URLConnection conn = url.openConnection();
long t=System.currentTimeMillis();
InputStream ins = conn.getInputStream();
Log.d("info", String.valueOf((System.currentTimeMillis()-t)));
The log says it takes about 5000 ms to get the inputstream.. Is there any way to speed this up? does anybody knows which technique the Android Market uses? This loads way faster than my app..
Thanks in advance! :)

When you try to get the data "manually" - via browser or via other means (wget, curl) how long does it take there.
On Android you also should take the mobile network into consideration that is usually significantly slower than for a desktop computer. Also latencies are bigger.
To me this sounds a lot like issues in the backend (e.g. trying to resolve the IP of the client and thus taking lots of time).

use Apache HttpClient instead of URLConnection:
Apache http client or URLConnection
EDIT(2012-02-07): no longer true on newer android platform please read: http://android-developers.blogspot.com/2011/09/androids-http-clients.html

Maybe that is how it is implemented and you can't do nothing. That is my guess.
My opinion is to do all connection based stuff on your own thread (to put in in background) and in foreground (main UI thread) entertain user. :)
I have played a little bit around this and it works fast enough for me... Here is my code:
private static HttpResponse doPost(String url, JSONStringer json) {
try {
HttpPost request = new HttpPost(url);
StringEntity entity;
entity = new StringEntity(json.toString());
entity.setContentType("application/json;charset=UTF-8");
entity.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json;charset=UTF-8"));
request.setEntity(entity);
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
return response;
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return null;
}
And somewhere else I call that method like:
HttpResponse httpResponse = doPost(url, json);
BufferedReader reader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8"));
It works fine for me...