Retrofit Example

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context=".MainActivity">

    <TextView

        android:id="@+id/tv_response"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_centerVertical="true"

        android:text="Hello Response here"

        android:textColor="#ff2323"

        android:textSize="22sp" />

</RelativeLayout>

dependencies {

    compile 'com.squareup.retrofit:retrofit:1.9.0'

}

public interface DetailsAPI {

    @GET("/key/value/one/two")

    void insertUser(Callback<JsonObject> jsonObjectCallback);

}

public class MainActivity extends AppCompatActivity {

    public static final String Root_url = "http://echo.jsontest.com/";

    TextView tv;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        tv = (TextView) findViewById(R.id.tv_response);

        insertUser();

    }

    private void insertUser() {

        RestAdapter adapter = new RestAdapter.Builder().setEndpoint(Root_url).build();

        DetailsAPI api = adapter.create(DetailsAPI.class);

        api.insertUser(new Callback<JsonObject>() {

            @Override

            public void success(JsonObject jsonObject, Response response) {

                Toast.makeText(MainActivity.this, "Success!" + "status is :" + response.getStatus(), Toast.LENGTH_SHORT).show();

                if (response.getStatus() == 200)

                    tv.setText("You got the data");

            }

            public void failure(RetrofitError error) {

                Toast.makeText(MainActivity.this, "try again!", Toast.LENGTH_SHORT).show();

            }

        });

    }

}