Develop Reference

I don't understand why 'onResponse()' is not triggered after successful response?

From the log I can see that the web service correctly returns the JSON to me. But for some reason it never enters the onResponse method.
MainActivity.java
OnResponse() method in getaccesstoken() not triggered after successful response
package com.example.alexandra.instagramlogin;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import com.example.alexandra.instagramlogin.models.AuthToken;
import com.example.alexandra.instagramlogin.rest.RestClient;
import com.example.alexandra.instagramlogin.rest.services.Auth;
import com.squareup.picasso.Picasso;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class MainActivity extends AppCompatActivity
implements AuthenticationListener {
private static final String TAG = "MainActivity";
private String token = null;
private String code = null;
private AppPreferences appPreferences = null;
private AuthenticationDialog authenticationDialog = null;
private Button button = null;
private View info = null;
AuthToken authToken = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = findViewById(R.id.btn_login);
info = findViewById(R.id.info);
appPreferences = new AppPreferences(this);
//check already have access token
}
public void login() {
button.setText("LOGOUT");
info.setVisibility(View.VISIBLE);
ImageView pic = findViewById(R.id.pic);
Picasso.with(this).load(appPreferences.getString(AppPreferences.PROFILE_PIC)).into(pic);
TextView id = findViewById(R.id.id);
id.setText(appPreferences.getString(AppPreferences.USER_ID));
TextView name = findViewById(R.id.name);
name.setText(appPreferences.getString(AppPreferences.USER_NAME));
}
public void logout() {
button.setText("INSTAGRAM LOGIN");
token = null;
info.setVisibility(View.GONE);
appPreferences.clear();
}
#Override
public void onTokenReceived(String auth_code) {
Log.d(TAG, auth_code);
appPreferences.putString(AppPreferences.CODE, auth_code);
code = auth_code;
getAccessToken(code);
}
//getting access token
private void getAccessToken(final String code) {
Auth auth = RestClient.getInstance();
Call<AuthToken>authTokenCall = auth.getAuthToken(getString(R.string.client_id),getString(R.string.client_secret),"authorization_code",getString(R.string.redirect_url),
code);
authTokenCall.enqueue(new Callback<AuthToken>() {
#Override
public void onResponse(Call<AuthToken> call, Response<AuthToken> response) {
Log.d(TAG, "onResponse: ");
}
#Override
public void onFailure(Call<AuthToken> call, Throwable t) {
}
});
}
public void onClick(View view) {
if(token!=null)
{
logout();
}
else {
authenticationDialog = new AuthenticationDialog(this, this);
authenticationDialog.setCancelable(true);
authenticationDialog.show();
}
}
}
pojo(AuthToken)
package com.example.alexandra.instagramlogin.models;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
public class AuthToken {
#SerializedName("access_token")
#Expose
private String access_token;
#SerializedName("user_id")
#Expose
private Integer user_id;
public String getAccessToken() {
return access_token;
}
public void setAccessToken(String accessToken) {
this.access_token = accessToken;
}
public Integer getUserId() {
return user_id;
}
public void setUserId(Integer userId) {
this.user_id = userId;
}
}
Auth.java
package com.example.alexandra.instagramlogin.rest.services;
import com.example.alexandra.instagramlogin.Classes.AuthorizationToken;
import com.example.alexandra.instagramlogin.models.AuthToken;
import retrofit2.Call;
import retrofit2.http.Body;
import retrofit2.http.Field;
import retrofit2.http.FormUrlEncoded;
import retrofit2.http.POST;
public interface Auth {
#FormUrlEncoded
#POST("oauth/access_token")
Call<AuthToken>getAuthToken(#Field("client_id")String clientid,#Field("client_secret")String client_secret,#Field("grant_type")String grant_type
,#Field("redirect_uri")String redirect_uri,#Field("code")String code);
}
Response
D/OkHttp: {"access_token": "IGQVJXWTcyNVBZANmFfeWNSQXUwQmdZAYlUtSHYxc1Q1dUlZAWTVPaTVTZA3dqYU00dC1ocjc4WDJwS2ZA2cVJjMTA3Rkx5QkN4alBlVjFNWjBndkJMcm45ZA0s3dk5HbXBFNnU5empGVGI0WXdrb1ZARZADktVlFjeVJIQUxGRnpv", "user_id": 17841401561947636}

I think you are not handling all case correctly like what if onFailure trigger for error.
I am not debugging you project so exact error i can tell you but i suggest you some links where you can find how to debug your code properly.
How to debug android apps

TMDB api trending endpoint call returns a null object

I am making an api call to themoviedb.org api in android using retrofit. I am expecting a json array with a list of movies in the response, however i get a null object reference when i call the getResults method of my POJO class. Kindly assist.
This is the error message i am getting;
2020-01-03 12:28:10.396 20851-20851/com.popularmovies E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.popularmovies, PID: 20851
java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.gson.JsonArray com.popularmovies.TrendingPojo.getResults()' on a null object reference
at com.popularmovies.TrendingFragment$1.onResponse(TrendingFragment.java:109)
at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:71)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7045)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:964)
Here is my api interface
import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Path;
import retrofit2.http.Query;
public interface TmdbApi {
final String BASE_URL = "https://api.themoviedb.org/4/";
#GET("list/{id}")
Call<CategoryJsonResponse> getMovies(#Path ("id") String id, #Query("api_key") String api_key);
#GET("discover/movie")
Call<DiscoverPOJO> getDiscover(#Query("sort_by") String sort_by,#Query("api_key") String api_key);
#GET("trending/{media_type}/{time_window}")
Call<TrendingPojo> getTrending(#Path("media_type") String media_type, #Path("time_window") String time_window, #Query("api_key") String api_key);
}
my problem is with the trending endpoint.
Below is my POJO class
package com.popularmovies;
import com.google.gson.JsonArray;
public class TrendingPojo {
private int page;
private JsonArray results;
private int total_results;
private int total_pages;
//Default constructor for api calls
public TrendingPojo(int page, JsonArray results, int total_pages, int total_results) {
this.page = page;
this.results = results;
this.total_results = total_results;
this.total_pages = total_pages;
}
public int getPage() {
return page;
}
public JsonArray getResults() {
return results;
}
public int getTotal_results() {
return total_results;
}
public int getTotal_pages() {
return total_pages;
}
public void setPage(int page) {
this.page = page;
}
public void setResults(JsonArray results) {
this.results = results;
}
public void setTotal_results(int total_results) {
this.total_results = total_results;
}
public void setTotal_pages(int total_pages) {
this.total_pages = total_pages;
}
}
Below is the fragment from which i make the api call using retrofit;
package com.popularmovies;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ProgressBar;
import android.widget.Toast;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.reflect.TypeToken;
import java.lang.reflect.Type;
import java.util.Collection;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
import static com.popularmovies.DiscoverFragment.API_KEY;
public class TrendingFragment extends Fragment implements MovieAdapter.MovieAdapterOnclickHandler {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private View rootView;
private ProgressBar progressBar;
private RecyclerView mRecyclerView;
private MovieAdapter movieAdapter;
private List<Movies> moviez;
public TrendingFragment() {
// Required empty public constructor
}
// TODO: Rename and change types and number of parameters
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_trending, container, false);
progressBar = rootView.findViewById(R.id.trending_pb);
progressBar.setVisibility(View.VISIBLE);
mRecyclerView = rootView.findViewById(R.id.trending_rv);
GridLayoutManager layoutManager = new GridLayoutManager(rootView.getContext(), 2);
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);
movieAdapter = new MovieAdapter(this);
mRecyclerView.setAdapter(movieAdapter);
getTrendingResponse();
return rootView;
}
// TODO: Rename method, update argument and hook method into UI event
private void getTrendingResponse(){
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(TmdbApi.BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
TmdbApi tmdbApi = retrofit.create(TmdbApi.class);
Call<TrendingPojo> call = tmdbApi.getTrending("movie","week",API_KEY);
call.enqueue(new Callback<TrendingPojo>() {
#Override
public void onResponse(Call<TrendingPojo> call, Response<TrendingPojo> response) {
TrendingPojo movies = response.body();
JsonArray allmovies;
allmovies = movies.getResults();
if(allmovies!= null){
for(int i = 0; i < allmovies.size(); i++){
Gson gson = new Gson();
Type listType = new TypeToken<Collection<Movies>>(){}.getType();
moviez = gson.fromJson(allmovies, listType);
}
movieAdapter.setData(moviez);
progressBar.setVisibility(View.INVISIBLE);
}
}
#Override
public void onFailure(Call<TrendingPojo> call, Throwable t) {
Toast.makeText(rootView.getContext(), t.getMessage(), Toast.LENGTH_LONG).show();
}
});
}
#Override
public void onDetach() {
super.onDetach();
}
#Override
public void onClick(int s) {
}
}
Finally here is a link to the api documentation for the trending endpoint.
https://developers.themoviedb.org/3/trending/get-trending

Turns out the problem was I was using a version 4 base URL which returns a 404 error code for some endpoints instead of version 3.
changing
"https://api.themoviedb.org/4/"
to
"https://api.themoviedb.org/3/"
was the solution.

how to get response for multiple JsonArray in retrofit2?

I have some JSON below.
{
"Table": [
{
"CMBL009001": "010001",
"NMBL009002": 0,
"CMBL009003": "",
"CMBL009004": "",
"CMBL009005": "",
"CMBL009006": "",
"NMBL009007": 0,
"BMBL009008": 0,
"NMBL009009": 0,
"CMBL009010": "ADMIN",
"CMBL009011": "",
"NMBL009012": 2,
"NMBL009013": 1
}
]
}
this is my model:
package com.example.showmyjsonapplicationuser;
import com.google.gson.annotations.SerializedName;
public class User {
#SerializedName("BMBL009008")
private Long mBMBL009008;
#SerializedName("CMBL009001")
private String mCMBL009001;
#SerializedName("CMBL009003")
private String mCMBL009003;
#SerializedName("CMBL009004")
private String mCMBL009004;
#SerializedName("CMBL009005")
private String mCMBL009005;
#SerializedName("CMBL009006")
private String mCMBL009006;
#SerializedName("CMBL009010")
private String mCMBL009010;
#SerializedName("CMBL009011")
private String mCMBL009011;
#SerializedName("NMBL009002")
private Long mNMBL009002;
#SerializedName("NMBL009007")
private Long mNMBL009007;
#SerializedName("NMBL009009")
private Long mNMBL009009;
#SerializedName("NMBL009012")
private Long mNMBL009012;
#SerializedName("NMBL009013")
private Long mNMBL009013;
public Long getBMBL009008() {
return mBMBL009008;
}
public void setBMBL009008(Long bMBL009008) {
mBMBL009008 = bMBL009008;
}
public String getCMBL009001() {
return mCMBL009001;
}
public void setCMBL009001(String cMBL009001) {
mCMBL009001 = cMBL009001;
}
public String getCMBL009003() {
return mCMBL009003;
}
public void setCMBL009003(String cMBL009003) {
mCMBL009003 = cMBL009003;
}
public String getCMBL009004() {
return mCMBL009004;
}
public void setCMBL009004(String cMBL009004) {
mCMBL009004 = cMBL009004;
}
public String getCMBL009005() {
return mCMBL009005;
}
public void setCMBL009005(String cMBL009005) {
mCMBL009005 = cMBL009005;
}
public String getCMBL009006() {
return mCMBL009006;
}
public void setCMBL009006(String cMBL009006) {
mCMBL009006 = cMBL009006;
}
public String getCMBL009010() {
return mCMBL009010;
}
public void setCMBL009010(String cMBL009010) {
mCMBL009010 = cMBL009010;
}
public String getCMBL009011() {
return mCMBL009011;
}
public void setCMBL009011(String cMBL009011) {
mCMBL009011 = cMBL009011;
}
public Long getNMBL009002() {
return mNMBL009002;
}
public void setNMBL009002(Long nMBL009002) {
mNMBL009002 = nMBL009002;
}
public Long getNMBL009007() {
return mNMBL009007;
}
public void setNMBL009007(Long nMBL009007) {
mNMBL009007 = nMBL009007;
}
public Long getNMBL009009() {
return mNMBL009009;
}
public void setNMBL009009(Long nMBL009009) {
mNMBL009009 = nMBL009009;
}
public Long getNMBL009012() {
return mNMBL009012;
}
public void setNMBL009012(Long nMBL009012) {
mNMBL009012 = nMBL009012;
}
public Long getNMBL009013() {
return mNMBL009013;
}
public void setNMBL009013(Long nMBL009013) {
mNMBL009013 = nMBL009013;
}
}
this is my retrofit class:
package com.example.showmyjsonapplicationuser;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory;
import retrofit2.converter.gson.GsonConverterFactory;
public class RetrofitSingleton {
private static Retrofit retrofit;
public static Retrofit getInstance() {
if (retrofit == null) {
retrofit = new Retrofit.Builder()
.baseUrl("http://192.168.200.10:6139/api/")
.addCallAdapterFactory(RxJava2CallAdapterFactory.create())
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
private RetrofitSingleton() {
}
}
this is provider class:
package com.example.showmyjsonapplicationuser.providers;
import com.example.showmyjsonapplicationuser.ApiService;
import com.example.showmyjsonapplicationuser.RetrofitSingleton;
public class ApiServiceProvider {
private static ApiService apiService;
public static ApiService provideApiService() {
if (apiService == null) {
apiService = RetrofitSingleton.getInstance().create(ApiService.class);
}
return apiService;
}
}
this is jsonUserResponse:
package com.example.showmyjsonapplicationuser;
public class JSONUserResponse {
private User[] Table;
public User[] getTable(){
return Table;
}
}
this is apiService:
package com.example.showmyjsonapplicationuser;
import retrofit2.Call;
import retrofit2.http.GET;
public interface ApiService {
#GET("values?url=<NewDataSet><Table><ver>1_02.01.06</ver><proc>003TOTALSELECT</proc><P1>ADMIN</P1><P2>123456</P2><P3>MBLTYPEVISIT1</P3></Table></NewDataSet>")
Call<JSONUserResponse> getUsersJSON();
}
this is mainViewModel:
`package com.example.showmyjsonapplicationuser;
import com.example.showmyjsonapplicationuser.providers.ApiServiceProvider;
import retrofit2.Call;
public class MainViewModel {
private ApiService apiService = ApiServiceProvider.provideApiService();
Call<JSONUserResponse> callUser = apiService.getUsersJSON();
}
this in main activity:
package com.example.showmyjsonapplicationuser;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Arrays;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class MainActivity extends AppCompatActivity {
private MainViewModel viewModel = new MainViewModel();
private ArrayList<User> data = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewModel.callUser.enqueue(new Callback<JSONUserResponse>() {
#Override
public void onResponse(Call<JSONUserResponse> call, Response<JSONUserResponse> response) {
JSONUserResponse jsonUserResponse = response.body();
assert jsonUserResponse != null;
data = new ArrayList<>(Arrays.asList(jsonUserResponse.getTable()));
Toast.makeText(MainActivity.this, "اطلاعات با موفقیت دریافت شد", Toast.LENGTH_LONG).show();
}
#Override
public void onFailure(Call<JSONUserResponse> call, Throwable t) {
Log.d("Error", t.getMessage());
}
});
}
}
the problem is that the response is null.

You need to create two model classes , one will be like below
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
public class Table {
#SerializedName("CMBL009001")
#Expose
private String cMBL009001;
#SerializedName("NMBL009002")
#Expose
private Integer nMBL009002;
#SerializedName("CMBL009003")
#Expose
private String cMBL009003;
#SerializedName("CMBL009004")
#Expose
private String cMBL009004;
#SerializedName("CMBL009005")
#Expose
private String cMBL009005;
#SerializedName("CMBL009006")
#Expose
private String cMBL009006;
#SerializedName("NMBL009007")
//getters and setters
}
Another will be
import java.util.List;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
public class TestModel {
#SerializedName("Table")
#Expose
private List<Table> table = null;
public List<Table> getTable() {
return table;
}
public void setTable(List<Table> table) {
this.table = table;
}
}
And then you can use the TestModel in your call.

Fetching Json from URL - null object reference [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 5 years ago.
I am trying to fetch an array from the data.police.uk website.
Unfortunately, when running the code an error comes up: java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference
Here's the code, no idea, what I am doing wrong:
package com.example.cosmin.crimerate.Latest_crimes;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import com.example.cosmin.crimerate.R;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class JsonCrimesActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_json_crimes);
final ListView listView = findViewById(R.id.crimesList);
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(Api.BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
Api api = retrofit.create(Api.class);
Call<List<Crime>> call = api.getCrimes();
call.enqueue(new Callback<List<Crime>>() {
#Override
public void onResponse(Call<List<Crime>> call, Response<List<Crime>> response) {
List<Crime> Crimes = response.body();
String[] crimeCategories = new String[Crimes.size()];
for (int i=0; i < Crimes.size();i++){
crimeCategories[i]= Crimes.get(i).getCategory();
}
listView.setAdapter(
new ArrayAdapter<String>(
getApplicationContext(),
android.R.layout.simple_list_item_1,
crimeCategories
)
);
}
#Override
public void onFailure(Call<List<Crime>> call, Throwable t) {
Toast.makeText(getApplicationContext(), t.getMessage(), Toast.LENGTH_SHORT).show();
}
});
}
}
That's the Api class:
public interface Api{
String BASE_URL = "https://data.police.uk/api/";
#GET("/crimes-no-location?category=all-crime&force=leicestershire&date=2017-02")
Call<List<Crime>> getCrimes();
Do you think it can be because of the array?
If you can please me give me a hint or anything what's happening.
Thank you for your help!
LE: CRIME MODEL:
public class Crime {
private String category;
private String persistent_id;
private String location_subtype;
private String id;
private String location;
private String context;
private String month;
private String location_type;
private String outcome_status;
public Crime(String category, String persistent_id, String location_subtype, String id, String location, String context, String month, String location_type, String outcome_status) {
this.category = category;
this.persistent_id = persistent_id;
this.location_subtype = location_subtype;
this.id = id;
this.location = location;
this.context = context;
this.month = month;
this.location_type = location_type;
this.outcome_status = outcome_status;
}
public String getCategory() {
return category;
}
public String getPersistent_id() {
return persistent_id;
}
public String getLocation_subtype() {
return location_subtype;
}
public String getId() {
return id;
}
public String getLocation() {
return location;
}
public String getContext() {
return context;
}
public String getMonth() {
return month;
}
public String getLocation_type() {
return location_type;
}
public String getOutcome_status() {
return outcome_status;
}
}

Make sure this piece of code if working fine.
List<Crime> Crimes = response.body();
Your Crimes List is probably empty or null.

Your response.body() is returning null. I'm pretty sure it's because you misconfigured your Api. As is, you're making an http call to the following uri (notice the double //):
https://data.police.uk/api//crimes-no-location?category=all-crime&force=leicestershire&date=2017-02
Remove the leading slash in your #GET

How to load data from json in expandable listview using retrofit?

I want to load question and answer in expandable listview from json using retrofit library. I dont know how to do this. Find me a solution.
Here is the two model class i am using.
public class QuestionResult {
boolean IsSuccess;
List<QuestionsModel> question;
public boolean isSuccess() {
return IsSuccess;
}
public List<QuestionsModel> getQuestion() {
return question;
}
}
And
public class QuestionsModel {
private int q_id;
private int category_id;
private String question;
private String answer;
public int getQ_id() {
return q_id;
}
public int getCategory_id() {
return category_id;
}
public String getQuestion() {
return question;
}
public String getAnswer() {
return answer;
}
}
Here is my Activity
public class QuestionBank extends AppCompatActivity {
#InjectView(R.id.ques_type_spinner)
Spinner courseSpinner;
#InjectView(R.id.home_btn_qbank)
Button homeButton;
#InjectView(R.id.no_questions)
TextView textView;
#InjectView(R.id.ques_ans_listview)
ExpandableListView listView;
List<String> courseNames;
ArrayAdapter<String> courseAdapter;
ExpandableListAdapter listAdapter;
List<QuestionResult> resultList;
ProgressDialog progress;
int selectedPosition;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_question_bank);
ButterKnife.inject(this);
StatusBarTheme.setStatusBarColor(this);
showCourseCategory();
homeButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
});
courseSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
selectedPosition = courseSpinner.getSelectedItemPosition() + 1;
Log.d("cat_id ", " " + selectedPosition);
loadQuestions(selectedPosition);
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
private void loadQuestions(final int selectedPosition) {
ApiInterface apiInterface = ApiClient.getClient(this).create(ApiInterface.class);
Call<QuestionResult> call = apiInterface.loadQuesAndAnswers(selectedPosition);
call.enqueue(new Callback<QuestionResult>() {
#Override
public void onResponse(Call<QuestionResult> call, Response<QuestionResult> response) {
List<QuestionsModel> questionsModelList = response.body().getQuestion();
if (questionsModelList != null) {
listAdapter = new ExpandListAdapter(QuestionBank.this, questionsModelList, selectedPosition);
listView.setAdapter(listAdapter);
} else {
listView.setVisibility(View.GONE);
textView.setVisibility(View.VISIBLE);
}
}
#Override
public void onFailure(Call<QuestionResult> call, Throwable t) {
}
});
}
private void showCourseCategory() {
ApiInterface apiInterface = ApiClient.getClient(this).create(ApiInterface.class);
Call<CategoryResult> call = apiInterface.loadCourseTitle();
progress = new ProgressDialog(QuestionBank.this);
progress.setMessage("Loading.. Please wait");
progress.show();
call.enqueue(new Callback<CategoryResult>() {
#Override
public void onResponse(Call<CategoryResult> call, Response<CategoryResult> response) {
if (progress.isShowing()) {
progress.dismiss();
}
if (response.body().isSuccess() && response.body().getCategory() != null) {
response.body().getCategory();
courseNames = new ArrayList<>();
for (CourseType courseType : response.body().getCategory()) {
courseNames.add(courseType.getCategory_title());
}
loadSpinner(courseNames);
}
}
#Override
public void onFailure(Call<CategoryResult> call, Throwable t) {
}
});
}
private void loadSpinner(List<String> educationTypeList) {
courseAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, educationTypeList);
courseAdapter.setDropDownViewResource(android.R.layout.simple_list_item_checked);
courseSpinner.setAdapter(courseAdapter);
}
}

Here is the complete code. Change it for your purposes. If anything will happen you can write comment i will answer.
Application.class
public class Application extends Application{
private static Application instance;
private I_Requests iWebEndpoint;
#Override
public void onCreate() {
super.onCreate();
instance = this;
}
public static Application i() {
return instance;
}
public I_Requests w() {
if(this.iWebEndpoint == null){
initRetrofit();
}
return iWebEndpoint;
}
private void initRetrofit(){
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client = new OkHttpClient
.Builder()
.addInterceptor(interceptor)
.readTimeout(1, TimeUnit.MINUTES)
.writeTimeout(1, TimeUnit.MINUTES)
.connectTimeout(1, TimeUnit.MINUTES)
.build();
client.readTimeoutMillis();
this.iWebEndpoint = new Retrofit.Builder()
.baseUrl(I_Requests.address)
.client(client)
.addConverterFactory(JacksonConverterFactory.create())
.build()
.create(I_Requests.class);
}
}
JacksonConverterFactory.class
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;
import com.fasterxml.jackson.databind.ObjectWriter;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import okhttp3.RequestBody;
import okhttp3.ResponseBody;
import retrofit2.Converter;
import retrofit2.Retrofit;
/**
* A {#linkplain Converter.Factory converter} which uses Jackson.
* <p>
* Because Jackson is so flexible in the types it supports, this converter assumes that it can
* handle all types. If you are mixing JSON serialization with something else (such as protocol
* buffers), you must {#linkplain Retrofit.Builder#addConverterFactory(Converter.Factory) add this
* instance} last to allow the other converters a chance to see their types.
*/
public final class JacksonConverterFactory extends Converter.Factory {
/** Create an instance using a default {#link ObjectMapper} instance for conversion. */
public static JacksonConverterFactory create() {
return create(new ObjectMapper());
}
/** Create an instance using {#code mapper} for conversion. */
public static JacksonConverterFactory create(ObjectMapper mapper) {
return new JacksonConverterFactory(mapper);
}
private final ObjectMapper mapper;
private JacksonConverterFactory(ObjectMapper mapper) {
if (mapper == null) throw new NullPointerException("mapper == null");
this.mapper = mapper;
}
#Override
public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations,
Retrofit retrofit) {
JavaType javaType = mapper.getTypeFactory().constructType(type);
ObjectReader reader = mapper.reader(javaType);
return new JacksonResponseBodyConverter<>(reader);
}
#Override
public Converter<?, RequestBody> requestBodyConverter(Type type,
Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) {
JavaType javaType = mapper.getTypeFactory().constructType(type);
ObjectWriter writer = mapper.writerWithType(javaType);
return new JacksonRequestBodyConverter<>(writer);
}
}
JacksonRequestBodyConverter.class
import com.fasterxml.jackson.databind.ObjectWriter;
import java.io.IOException;
import okhttp3.MediaType;
import okhttp3.RequestBody;
import retrofit2.Converter;
final class JacksonRequestBodyConverter<T> implements Converter<T, RequestBody> {
private static final MediaType MEDIA_TYPE = MediaType.parse("application/json; charset=UTF-8");
private final ObjectWriter adapter;
JacksonRequestBodyConverter(ObjectWriter adapter) {
this.adapter = adapter;
}
#Override public RequestBody convert(T value) throws IOException {
byte[] bytes = adapter.writeValueAsBytes(value);
return RequestBody.create(MEDIA_TYPE, bytes);
}
}
JacksonResponseBodyConverter.class
import com.fasterxml.jackson.databind.ObjectReader;
import java.io.IOException;
import okhttp3.ResponseBody;
import retrofit2.Converter;
final class JacksonResponseBodyConverter<T> implements Converter<ResponseBody, T> {
private final ObjectReader adapter;
JacksonResponseBodyConverter(ObjectReader adapter) {
this.adapter = adapter;
}
#Override public T convert(ResponseBody value) throws IOException {
try {
return adapter.readValue(value.charStream());
} finally {
value.close();
}
}
}
I_Request.interface
import java.util.ArrayList;
import manqaro.com.projectz.ServerSide.Response.TestData;
import manqaro.com.projectz.ServerSide.Response.TestResponse;
import retrofit2.Call;
import retrofit2.http.Field;
import retrofit2.http.FormUrlEncoded;
import retrofit2.http.GET;
import retrofit2.http.POST;
public interface I_Requests {
//PUT HERE YOUR SERVER MAIN ADDRES
String address = "http://goto.xcodes.club";
//SAMPLE EXAMPLE OF POST TYPE , YOU SHOULD CHANGE EVERYTHING YOU WANT.
//IN THIS EXAMPLE YOU WILL GET JSON DATA WHICH WILL BE CONVERTED TO JAVA OBJECT.
#FormUrlEncoded
//Here YOU HAVE TO GIVE ADDRESS TO SPECIFIC CALL
#GET("/api/v1/objects/")
Call<TestResponse<ArrayList<TestData>>> login(
);
#FormUrlEncoded
#POST("/api/v1/objects/")
Call<TestResponse<ArrayList<TestData>>> register(
);
}
TestResponse.class
import com.fasterxml.jackson.annotation.JsonProperty;
/**
* Created by ArsenSench on 11/9/2016.
*/
public class TestResponse<T> {
#JsonProperty("status")
public int status;
#JsonProperty("message")
public String message;
#JsonProperty("data")
public T data;
}
TestData.class
import com.fasterxml.jackson.annotation.JsonProperty;
/**
* Created by ArsenSench on 11/9/2016.
*/
public class TestData extends {
#JsonProperty("id")
public int id;
#JsonProperty("name")
public String name;
#JsonProperty("description")
public String description;
#JsonProperty("avatar")
public String avatar;
#JsonProperty("rate")
public int rate;
}
ServerCalls.class
import android.content.Context;
import android.util.Log;
import android.widget.Toast;
import java.util.ArrayList;
import manqaro.com.projectz.ServerSide.Application.Tickle_Application;
import manqaro.com.projectz.ServerSide.Response.TestData;
import manqaro.com.projectz.ServerSide.Response.TestResponse;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
/**
* Created by ArsenSench on 11/9/2016.
*/
public class ServerCalls {
Context context;
public ServerCalls(Context context){
this.context = context;
}
public void testCallBack(){
Tickle_Application.i().w().login().enqueue(new Callback<TestResponse<ArrayList<TestData>>>() {
#Override
public void onResponse(Call<TestResponse<ArrayList<TestData>>> call, Response<TestResponse<ArrayList<TestData>>> response) {
if(response.code()==200){
if(response.body().status==200){
Toast.makeText(context, response.body().data.get(0).name, Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(context, "No Name", Toast.LENGTH_SHORT).show();
}
}
else{
Toast.makeText(context, "No Connection", Toast.LENGTH_SHORT).show();
}
}
#Override
public void onFailure(Call<TestResponse<ArrayList<TestData>>> call, Throwable t) {
Toast.makeText(context, t.getCause().getMessage(), Toast.LENGTH_SHORT).show();
Log.e("jex", "onFailure: " + t.getCause().getMessage() );
}
});
}
}
TestActivity.activity
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import manqaro.com.projectz.R;
import manqaro.com.projectz.ServerSide.Main.ServerCalls;
public class TestActivity extends AppCompatActivity {
ServerCalls sc = new ServerCalls(this);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
}
public void clickThatShit(View view){
sc.testCallBack();
}
}
Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="your.package.name">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:name=".Application"
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:largeHeap="true"
android:supportsRtl="true"
android:theme="#style/AppTheme"
tools:replace="android:icon">
<activity
android:name=".TestActivity">
</activity>
</application>
</manifest>
build.gradle(module app)
Include these dependencies in yourdependencies
compile 'com.squareup.retrofit2:retrofit:2.0.0'
compile 'com.squareup.okhttp3:logging-interceptor:3.2.0'
compile 'com.fasterxml.jackson.core:jackson-databind:2.7.3'
compile 'com.fasterxml.jackson.core:jackson-annotations:2.7.3'
Include this lines in your android{} block
packagingOptions {
exclude 'META-INF/LICENSE'
exclude 'META-INF/NOTICE'
}