Q:

Sending Json POST to server using name value pair

I am  sending Json Post request to server to through url: http://www.xyz.com/login
request structure:
{"requestdata":{"password":"abc","devicetype":"phone","username":"amrit@pqr.com","locale":"in"},"requestcode":10}

Code Snapshot:
MainActivity:
    // Building post parameters
    // key and value pair
    List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>();
    nameValuePair.add(new BasicNameValuePair("requestcode", "10"));
    nameValuePair.add(new BasicNameValuePair("devicetype", "phone"));
    nameValuePair.add(new BasicNameValuePair("locale", "in"));
    nameValuePair.add(new BasicNameValuePair("username", "amrit@pqr.com"));
    nameValuePair.add(new BasicNameValuePair("password", "abc"));

    RestPost post = new RestPost(loginUrl, nameValuePair);
    String Response = post.postData();
    Log.i("Response:", Response);

RestPost class
    import java.io.BufferedReader;
      import java.io.IOException;
      import java.io.InputStream;
      import java.io.InputStreamReader;
      import java.util.List;
      import org.apache.http.HttpEntity;
      import org.apache.http.HttpResponse;
      import org.apache.http.NameValuePair;
      import org.apache.http.StatusLine;
      import org.apache.http.client.ClientProtocolException;
      import org.apache.http.client.HttpClient;
      import org.apache.http.client.entity.UrlEncodedFormEntity;
      import org.apache.http.client.methods.HttpPost;
      import org.apache.http.impl.client.DefaultHttpClient;
      import android.util.Log;

     public class RestPost {
       String url;
       List<NameValuePair> nameValuePairs;

    public RestPost(String str, List<NameValuePair> params) {
        this.url = str;
        this.nameValuePairs = params;
    }

    public String postData() {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(this.url);
        StringBuilder builder = new StringBuilder();

        try {
            httppost.setEntity(new UrlEncodedFormEntity(this.nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            Log.d("RestClient", "Status Code : " + statusCode);

            HttpEntity entity = response.getEntity();
            InputStream content = entity.getContent();
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    content));
            String line;
            while ((line = reader.readLine()) != null) {
                builder.append(line);
            }

        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }
        return builder.toString();
    }
}

But I'm not getting appropriate response, could anyone help me in sending appropriate format for getting server response. Thanks in advance.
Response which I'm getting:
{"error":{"resultCode":"400","status":"Invalid Request format"}}

A:

You are currently sending the JSON in the form of 
{
    "requestcode": "10",
    "devicetype": "phone",
    "locale": "in",
    "username": "amrit@pqr.com",
    "password": "abc"
}

Which isn't the form the server is asking for. Try creating a string of the JSON you want to send. Then use:
httppost.setEntity(new StringEntity(jsonString, "UTF8"));
httppost.setHeader("Content-type", "application/json");

To send the string to the server.

