Server communication in Android

In Android we can communicate with server using HTTP request methods for getting some details from the server.We use RESTful service.Mainly we use two types of HTTP request HTTP GET(),HTTP POST() methods.

In some case we have to give some values to the server for fetching some informations, then we use commonly HTTP POST() and if we simply want to request for some datas we use HTTP GET().

Lets see HTTP POST() method.

public void getResponse(String a, String b) {

    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("URL"); //here write the url

    List < NameValuePair > nameValueList = new ArrayList < NameValuePair > (2);
    nameValueList.add(new BasicNameValuePair("keyword", a));
    nameValueList.add(new BasicNameValuePair("keyword", b));

    try {
        httppost.setEntity(new UrlEncodedFormEntity(nameValueList));

        HttpResponse response = httpclient.execute(httppost);
        Log.i("Tag", response.getStatusLine().toString());
        String responseStr = EntityUtils.toString(response.getEntity());

    } catch (Exception e) {

    }

}

In the above method we are passing two string values a and b, using namevaluepair method. Finally we get the response from the server  in responseStr.

HTTP GET() method

public void getResponse() {

    URL url;
    try {
        url = new URL("URL"); //here write the url

        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setReadTimeout(10000);
        conn.setConnectTimeout(15000);
        conn.setRequestMethod("GET");
        conn.setRequestProperty("Content-length", "0");
        conn.setAllowUserInteraction(false);
        // Starts the query
        conn.connect();
        int status = conn.getResponseCode();
        StringBuilder sb = new StringBuilder();
        switch (status) {
            case 200:
            case 201:
                BufferedReader br = new BufferedReader(new InputStreamReader(
                    conn.getInputStream()));
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line + "\n");
                }
                br.close();
                String response = sb.toString();

        }

    } catch (Exception e) {

    }
}

Here we are using HTTP GET() method.At first connection is established.Here I am checking the status line: If the request is procesed succesfully i am getting status code as 201.Finally We get the response in the string response;

We can also send values using HTTP GET()method by appending values with the URL,but commonly we won't use it.HTTP POST method is considered to be more secure than HTTP GET() method.