This example shows how to communicate between server and an android phone with Retrofit.
Dependencies
implementation 'com.squareup.retrofit2:retrofit:2.4.0' implementation 'com.google.code.gson:gson:2.8.2' implementation 'com.squareup.retrofit2:converter-gson:2.4.0'
APIService.java
package com.a4akhilsudha.xxx.Retrofit;
import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Query;
public interface APIService {
@GET("/api/get_questions.php")
//@FormUrlEncoded
Call<DataResponse> qstns(@Query("offset") String offset,
@Query("category") String category,
@Query("lang") String language);
@GET("/api/get_exams.php?exam=exam")
//@FormUrlEncoded
Call<DataResponse_examList> examList();
}
ApiUtils.java
package com.a4akhilsudha.xxx.Retrofit;
public class ApiUtils {
private ApiUtils() {}
public static final String BASE_URL = "https://xxx.a4akhilsudha.com/";
public static APIService getAPIService() {
return RetrofitClient.getClient(BASE_URL).create(APIService.class);
}
}
DataResponse.java
package com.a4akhilsudha.xxx.Retrofit;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
import java.util.List;
public class DataResponse {
@SerializedName("status")
@Expose
private String status;
@SerializedName("status_message")
@Expose
private String statusMessage;
@SerializedName("data")
@Expose
private List<Questions> data = null;
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public String getStatusMessage() {
return statusMessage;
}
public void setStatusMessage(String statusMessage) {
this.statusMessage = statusMessage;
}
public List<Questions> getData() {
return data;
}
public void setData(List<Questions> data) {
this.data = data;
}
}
RetrofitClient.java
package com.a4akhilsudha.xxx.Retrofit;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class RetrofitClient {
private static Retrofit retrofit = null;
public static Retrofit getClient(String baseUrl) {
if (retrofit==null) {
retrofit = new Retrofit.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
}
MainActivity.java
package com.a4akhilsudha.xxx.Activities;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.appcompat.widget.Toolbar;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Toast;
import com.a4akhilsudha.xxx.R;
import com.a4akhilsudha.xxx.Retrofit.APIService;
import com.a4akhilsudha.xxx.Retrofit.ApiUtils;
import com.a4akhilsudha.xxx.Retrofit.DataResponseImages;
import com.a4akhilsudha.xxx.Retrofit.ImagesDataProvider;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.gson.Gson;
import java.util.ArrayList;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class MainActivity extends AppCompatActivity {
Toolbar toolbar;
APIService mAPIService;
RecyclerView trollsRecycler;
TrollsAdapter trollsAdapter;
List<ImagesDataProvider> imagesDataProviderList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_trolls);
toolbar = findViewById(R.id.toolbar);
trollsRecycler = findViewById(R.id.trollsRecycler);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("PSC Trolls");
toolbar.setTitleTextColor(Color.WHITE);
toolbar.setNavigationIcon(R.drawable.round_arrow_back_24);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
onBackPressed();
}
});
mAPIService = ApiUtils.getAPIService();
imagesDataProviderList = new ArrayList<>();
trollsAdapter = new TrollsAdapter(this, imagesDataProviderList);
trollsRecycler.setHasFixedSize(true);
trollsRecycler.setLayoutManager(new GridLayoutManager(this, LinearLayoutManager.VERTICAL));
trollsRecycler.setAdapter(trollsAdapter);
RequestData();
}
public void RequestData() {
final AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(TrollsActivity.this);
LayoutInflater inflater = LayoutInflater.from(TrollsActivity.this);
final View dialogView = inflater.inflate(R.layout.progress, null);
dialogBuilder.setView(dialogView);
final AlertDialog alertDialog = dialogBuilder.create();
alertDialog.show();
alertDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
mAPIService.trolls().enqueue(new Callback<DataResponseImages>() {
@Override
public void onResponse(Call<DataResponseImages> call, Response<DataResponseImages> response) {
if(response.isSuccessful()) {
String json = new Gson().toJson(response);
if (response.body().getStatus().equals("success"))
{
imagesDataProviderList.addAll(response.body().getData());
trollsRecycler.getAdapter().notifyDataSetChanged();
}
else if (response.body().getStatus().equals("error") && response.body().getStatusMessage().equals("no_data"))
{
Toast.makeText(TrollsActivity.this, "No data found", Toast.LENGTH_SHORT).show();
// ShowCompletionDialog("2","You have Completed All the questions","Do you want to restart again?","Yes","No");
}
else
{
Toast.makeText(TrollsActivity.this, "Something went wrong", Toast.LENGTH_SHORT).show();
}
Log.i("TAG", "post submitted to API." + response.body().toString());
}
alertDialog.dismiss();
}
@Override
public void onFailure(Call<DataResponseImages> call, Throwable t) {
alertDialog.dismiss();
if (t.toString().contains("timeout"))
{
Toast.makeText(TrollsActivity.this, "Timeout" +
"", Toast.LENGTH_SHORT).show();
RequestData();
}
Log.e("TAG", "Unable to submit post to API.");
}
});
}
}
TrollsAdapter.java
package com.a4akhilsudha.xxx.Adapters;
import android.content.Context;
import androidx.recyclerview.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.a4akhilsudha.xxx.R;
import com.a4akhilsudha.xxx.Retrofit.ImagesDataProvider;
import com.bumptech.glide.Glide;
import java.util.List;
/**
* Created by a4akhilsudha.
*/
public class TrollsAdapter extends RecyclerView.Adapter<TrollsAdapter.MyViewHolder>{
Context context;
List<ImagesDataProvider> imagesDataProviderList;
public class MyViewHolder extends RecyclerView.ViewHolder {
public ImageView troll_img;
public MyViewHolder(View view) {
super(view);
troll_img = view.findViewById(R.id.troll_img);
}
}
public TrollsAdapter(Context context, List<ImagesDataProvider> imagesDataProviderList) {
this.context = context;
this.imagesDataProviderList = imagesDataProviderList;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.troll_item, parent, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
final ImagesDataProvider imagesDataProvider = imagesDataProviderList.get(position);
// holder.rdo_grp.clearCheck();
Glide.with(context).load(imagesDataProvider.getImage()).into(holder.troll_img);
}
@Override
public int getItemCount() {
return imagesDataProviderList.size();
}
}
