How do I call REST API from an android app? [closed]

1. If you want to integrate Retrofit (all steps defined here):

Goto my blog : retrofit with kotlin

2. Please use android-async-http library.

the link below explains everything step by step.

http://loopj.com/android-async-http/

Here are sample apps:

1. http://www.techrepublic.com/blog/software-engineer/calling-restful-services-from-your-android-app/

2. http://blog.strikeiron.com/bid/73189/Integrate-a-REST-API-into-Android-Application-in-less-than-15-minutes

Create a class :

public class HttpUtils {  private static final String BASE_URL = "http://api.twitter.com/1/";   private static AsyncHttpClient client = new AsyncHttpClient();  public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {      client.get(getAbsoluteUrl(url), params, responseHandler);  }  public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {      client.post(getAbsoluteUrl(url), params, responseHandler);  }        public static void getByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {      client.get(url, params, responseHandler);  }  public static void postByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {      client.post(url, params, responseHandler);  }  private static String getAbsoluteUrl(String relativeUrl) {      return BASE_URL + relativeUrl;  }}

Call Method :

    RequestParams rp = new RequestParams();    rp.add("username", "aaa"); rp.add("password", "aaa@123");                        HttpUtils.post(AppConstant.URL_FEED, rp, new JsonHttpResponseHandler() {        @Override        public void onSuccess(int statusCode, Header[] headers, JSONObject response) {            // If the response is JSONObject instead of expected JSONArray            Log.d("asd", "---------------- this is response : " + response);            try {                JSONObject serverResp = new JSONObject(response.toString());                                                            } catch (JSONException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }                           }                    @Override        public void onSuccess(int statusCode, Header[] headers, JSONArray timeline) {            // Pull out the first event on the public timeline                            }    });

Please grant internet permission in your manifest file.

 <uses-permission android:name="android.permission.INTERNET" />

you can add compile 'com.loopj.android:android-async-http:1.4.9' for Header[] and compile 'org.json:json:20160212' for JSONObject in build.gradle file if required.