Retrofit Android Example

 Why do we use retrofit in Android? :

Retrofit is used to perform the following tasks: It manages the process of receiving, sending, and creating HTTP requests and responses. It alternates IP addresses if there is a connection to a web service failure. It caches responses to avoid sending duplicate requests :

Step-1: Make Retrofit Client.Java Class  For Networking  :

public class RetrofitClient {

    private static final String BASE_URL ="https://pass website Domain Name/api/";
    private static RetrofitClient mInstance;
    private Retrofit retrofit;


    private RetrofitClient(){
       
        OkHttpClient.Builder httpClient = new OkHttpClient.Builder()
                .callTimeout(2, TimeUnit.MINUTES)
                .connectTimeout(10, TimeUnit.SECONDS)
                .readTimeout(30, TimeUnit.SECONDS)
                .writeTimeout(30, TimeUnit.SECONDS);

        retrofit = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .client(httpClient.build())
                .build();
    }

    public static synchronized RetrofitClient getInstance(){
        if(mInstance == null){
            mInstance = new RetrofitClient();
        }
        return mInstance;
    }

    public Api getApi(){
        return retrofit.create(Api.class);
    }


}

Step-2 Make  Api interface Store Api;

public interface Api {

    @FormUrlEncoded
    @POST("pass after api word here")
    Call<GetAllBlogResponseModel> userNo(
//Pass all faild  here 
            @Field("Mobile") String Mobile
    );
}

Main Activity.java class code :

 if (Validator.getInstance().isNetworkAvailable(currentActivity)) {
        String pageno = String.valueOf(currentPage);

        String pagesize = String.valueOf(PageSize);


        Call<GetAllBlogResponseModel> call = RetrofitClient.getInstance()
                .getApi().getuserNo(Pass all value of given Fiald here);

        call.enqueue(new Callback<GetAllBlogResponseModel>() {
            @Override
            public void onResponse(Call<GetAllBlogResponseModel> call, Response<GetAllBlogResponseModel> response) {
                if (response.isSuccessful()) {
                    swipeRefresh.setRefreshing(false);
                    GetAllBlogResponseModel responseModel = response.body();
                    String status = String.valueOf(responseModel.getStatus());
                    if (status.equals("1")) {


                           
                 
                    } else if (status.equals("0")) {
                        swipeRefresh.setRefreshing(false);
                        Toast.makeText(currentActivity, Log.e("TAG", responseModel.toString()), Toast.LENGTH_SHORT).show();
                    }

                } else if (response.code() == 401) {
                    swipeRefresh.setRefreshing(false);
                    Toast.makeText(currentActivity, "Your Session has been Expiered,Please Login Again..", Toast.LENGTH_SHORT).show();
                } else if (response.code() == 500) {
                    swipeRefresh.setRefreshing(false);
                    Toast.makeText(currentActivity, "Server Error", Toast.LENGTH_SHORT).show();
                } else {
                    swipeRefresh.setRefreshing(false);
                    Toast.makeText(currentActivity, "Failed to Retrieve Items..", Toast.LENGTH_SHORT).show();
                }
            }

            @Override
            public void onFailure(Call<GetAllBlogResponseModel> call, Throwable t) {
                swipeRefresh.setRefreshing(false);
                if (t instanceof SocketTimeoutException) {
                    cancelProgressDialog();
                    try {
                        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(currentActivity);
                        dialogBuilder.setMessage("oops! it seems there is a slow network connection issue.");

                        dialogBuilder.setPositiveButton("OK", (dialog, which) -> {


                                    dialog.dismiss();
                                }
                        );

                        dialogBuilder.setIcon(R.drawable.aajjo_logo_final);
                        dialogBuilder.setTitle("Network Connection.");

                        AlertDialog alertDialog = dialogBuilder.create();
                        alertDialog.show();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                } else {
                    cancelProgressDialog();
                    Toast.makeText(currentActivity, t.toString(), Toast.LENGTH_SHORT).show();

                }
            }
        });
    } else {
        //show alert Dialog Box 
    }
}
Retrofit dependencies :
implementation 'com.squareup.retrofit2:retrofit:2.6.2'  //for upload multiple image
implementation 'com.squareup.retrofit2:converter-gson:2.6.2'  //for upload multiple image