Develop Reference

Open an specific activity when I click an item from an recyclerView

I need some help with two of my recycler views(one named "recentRecycler", and the other "topPlacesRecycler").My question is, how do I make to be redirected on a specific Activity when I click a specific item from the recycler. For example:
1- when I click the first item from the "recentRecycler" to be redirected to "Parlament.class"
2- when I click the first item from the "topPlacesRecycler" to be redirected to "Ramada.class"
etc.
My Main Activity which is named "BUCint" (The code from the bottom is from a drawerlayout that I use for my project)
public class BUCint extends AppCompatActivity {
DrawerLayout drawerLayout;
RecyclerView recentRecycler, topPlacesRecycler;
RecentsAdapter recentsAdapter;
TopPlacesAdapter topPlacesAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_buc_int);
drawerLayout = findViewById(R.id.drawer_layout);
List<RecentsData> recentsDataList = new ArrayList<>();
recentsDataList.add(new RecentsData("Palatul Parlamentului","Cladire administrativă","40 lei",R.drawable.palatulparlamentului));
recentsDataList.add(new RecentsData("Arcul de Triumf","Monument istoric","Gratis",R.drawable.arctriumf));
recentsDataList.add(new RecentsData("Carturesti Carusel","Librarie","Gratis",R.drawable.carturesti));
recentsDataList.add(new RecentsData("Parcul Herăstrău","Parc","Gratis",R.drawable.parculherastrau));
recentsDataList.add(new RecentsData("Parcul Cișmigiu","Parc","Gratis",R.drawable.parculcismigiu));
recentsDataList.add(new RecentsData("Muzeul Antipa","Muzeu","20 lei",R.drawable.muzeulantipa));
setRecentRecycler(recentsDataList);
List<TopPlacesData> topPlacesDataList = new ArrayList<>();
topPlacesDataList.add(new TopPlacesData("Ramada Parc","Sectorul 1","227 lei",R.drawable.ramadaparc));
topPlacesDataList.add(new TopPlacesData("Berthelot","Sectorul 1","207 lei",R.drawable.bethelot));
topPlacesDataList.add(new TopPlacesData("Union Plaza","Centru","215 lei",R.drawable.unionplaza));
topPlacesDataList.add(new TopPlacesData("Rin Grande","Sectorul 4","223 lei",R.drawable.ringrande));
topPlacesDataList.add(new TopPlacesData("Hilton Garden","Centru","240 lei",R.drawable.hiltongarden));
setTopPlacesRecycler(topPlacesDataList);
}
private void setRecentRecycler(List<RecentsData> recentsDataList){
recentRecycler = findViewById(R.id.recent_recycler);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this, RecyclerView.HORIZONTAL, false);
recentRecycler.setLayoutManager(layoutManager);
recentsAdapter = new RecentsAdapter(this, recentsDataList);
recentRecycler.setAdapter(recentsAdapter);
}
private void setTopPlacesRecycler(List<TopPlacesData> topPlacesDataList){
topPlacesRecycler = findViewById(R.id.top_places_recycler);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this, RecyclerView.VERTICAL, false);
topPlacesRecycler.setLayoutManager(layoutManager);
topPlacesAdapter = new TopPlacesAdapter(this, topPlacesDataList);
topPlacesRecycler.setAdapter(topPlacesAdapter);
}
public void ClickMenu(View view){
BUCM.openDrawer(drawerLayout);
}
public void ClickLogo(View view){
BUCM.closeDrawer(drawerLayout);
}
public void ClickHome(View view){
BUCM.redirectActivity(this, Acasa.class);
}
public void ClickLinii(View view){
BUCM.redirectActivity(this,BUClinii.class);
}
public void ClickPreturi(View view){
BUCM.redirectActivity(this, BUCpreturi.class);
}
public void Clickint(View view){
recreate();
}
public void ClickSetari(View view) {
BUCM.redirectActivity(this, Setari.class);
}
public void ClickInformatii(View view){
BUCM.redirectActivity(this, Informatii.class);
}
public void ClickLogout(View view){
BUCM.logout(this);
}
#Override
protected void onPause(){
super.onPause();
BUCM.closeDrawer(drawerLayout);
}
}
The Adapter for recentRecycler, named RecentsAdapter
public class RecentsAdapter extends RecyclerView.Adapter<RecentsAdapter.RecentsViewHolder> {
Context context;
List<RecentsData> recentsDataList;
public RecentsAdapter(Context context, List<RecentsData> recentsDataList) {
this.context = context;
this.recentsDataList = recentsDataList;
}
#NonNull
#Override
public RecentsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.recents_row_item, parent, false);
return new RecentsViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull RecentsViewHolder holder, int position) {
holder.countryName.setText(recentsDataList.get(position).getCountryName());
holder.placeName.setText(recentsDataList.get(position).getPlaceName());
holder.price.setText(recentsDataList.get(position).getPrice());
holder.placeImage.setImageResource(recentsDataList.get(position).getImageUrl());
}
#Override
public int getItemCount() {
return recentsDataList.size();
}
public static final class RecentsViewHolder extends RecyclerView.ViewHolder{
ImageView placeImage;
TextView placeName, countryName, price;
public RecentsViewHolder(#NonNull View itemView) {
super(itemView);
placeImage = itemView.findViewById(R.id.place_image);
placeName = itemView.findViewById(R.id.place_name);
countryName = itemView.findViewById(R.id.country_name);
price = itemView.findViewById(R.id.price);
}
}
}
The DataModel for recentRecycler, named RecentsData
package com.example.spinner.model;
public class RecentsData {
String placeName;
String countryName;
String price;
Integer imageUrl;
public Integer getImageUrl() {
return imageUrl;
}
public void setImageUrl(Integer imageUrl) {
this.imageUrl = imageUrl;
}
public RecentsData(String placeName, String countryName, String price, Integer imageUrl) {
this.placeName = placeName;
this.countryName = countryName;
this.price = price;
this.imageUrl = imageUrl;
}
public String getPlaceName() {
return placeName;
}
public void setPlaceName(String placeName) {
this.placeName = placeName;
}
public String getCountryName() {
return countryName;
}
public void setCountryName(String countryName) {
this.countryName = countryName;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
}
The Adapter for topPlacesRecycler, named TopPlacesAdapter
public class TopPlacesAdapter extends RecyclerView.Adapter<TopPlacesAdapter.TopPlacesViewHolder> {
Context context;
List<TopPlacesData> topPlacesDataList;
public TopPlacesAdapter(Context context, List<TopPlacesData> topPlacesDataList) {
this.context = context;
this.topPlacesDataList = topPlacesDataList;
}
#NonNull
#Override
public TopPlacesViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.top_places_row_item, parent, false);
return new TopPlacesViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull TopPlacesViewHolder holder, int position) {
holder.countryName.setText(topPlacesDataList.get(position).getCountryName());
holder.placeName.setText(topPlacesDataList.get(position).getPlaceName());
holder.price.setText(topPlacesDataList.get(position).getPrice());
holder.placeImage.setImageResource(topPlacesDataList.get(position).getImageUrl());
}
#Override
public int getItemCount() {
return topPlacesDataList.size();
}
public static final class TopPlacesViewHolder extends RecyclerView.ViewHolder{
ImageView placeImage;
TextView placeName, countryName, price;
public TopPlacesViewHolder(#NonNull View itemView) {
super(itemView);
placeImage = itemView.findViewById(R.id.place_image);
placeName = itemView.findViewById(R.id.place_name);
countryName = itemView.findViewById(R.id.country_name);
price = itemView.findViewById(R.id.price);
}
}
}
The DataModel for topPlacesRecycler, named TopPlacesData
public class TopPlacesData {
String placeName;
String countryName;
String price;
Integer imageUrl;
public Integer getImageUrl() {
return imageUrl;
}
public void setImageUrl(Integer imageUrl) {
this.imageUrl = imageUrl;
}
public TopPlacesData(String placeName, String countryName, String price, Integer imageUrl) {
this.placeName = placeName;
this.countryName = countryName;
this.price = price;
this.imageUrl = imageUrl;
}
public String getPlaceName() {
return placeName;
}
public void setPlaceName(String placeName) {
this.placeName = placeName;
}
public String getCountryName() {
return countryName;
}
public void setCountryName(String countryName) {
this.countryName = countryName;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
}
I'm pretty new with Android Studio so every feedback would be gladly accepted.
Thanks in advance!

The best solution that does not overload the adapter would be to use interface.
Declare an interface in your adapter like this...
public class RecentsAdapter extends RecyclerView.Adapter<RecentsAdapter.RecentsViewHolder> {
Context context;
List<RecentsData> recentsDataList;
private RecentsAdapter.OnRecentItemclickListener listener;
public void setOnRecentItemclickListener(RecentsAdapter.OnRecentItemclickListener listener){
this.listener = listener;
}
public RecentsAdapter(Context context, List<RecentsData> recentsDataList) {
this.context = context;
this.recentsDataList = recentsDataList;
}
#NonNull
#Override
public RecentsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.recents_row_item, parent, false);
return new RecentsViewHolder(view, listener);
}
#Override
public void onBindViewHolder(#NonNull RecentsViewHolder holder, int position) {
holder.countryName.setText(recentsDataList.get(position).getCountryName());
holder.placeName.setText(recentsDataList.get(position).getPlaceName());
holder.price.setText(recentsDataList.get(position).getPrice());
holder.placeImage.setImageResource(recentsDataList.get(position).getImageUrl());
}
#Override
public int getItemCount() {
return recentsDataList.size();
}
public static final class RecentsViewHolder extends RecyclerView.ViewHolder{
ImageView placeImage;
TextView placeName, countryName, price;
public RecentsViewHolder(#NonNull View itemView, RecentsAdapter.OnRecentItemclickListener listener) {
super(itemView);
placeImage = itemView.findViewById(R.id.place_image);
placeName = itemView.findViewById(R.id.place_name);
countryName = itemView.findViewById(R.id.country_name);
price = itemView.findViewById(R.id.price);
itemView.setOnclickListener( -> {
if(listner == null)return;
int pos = getAdapterposition()
if(pos == RecyclerView.NO_POSITION)return;
listner.onRecentItemclickListener(pos);
});
}
}
public interface OnRecentItemclickListener {
void onRecentItemClickListener(int position);
}
}
Add then in you activity
private void setRecentRecycler(List<RecentsData> recentsDataList){
recentRecycler = findViewById(R.id.recent_recycler);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this, RecyclerView.HORIZONTAL, false);
recentRecycler.setLayoutManager(layoutManager);
recentsAdapter = new RecentsAdapter(this, recentsDataList);
recentRecycler.setAdapter(recentsAdapter);
recentsAdapter.setOnRecentItemclickListener(this::onOpenParlamentClass)
}
private void onOpenParlamentClass(int position){
//perform your intent here. you can also get the clicked item using the position of the data list and pass it to the receiving activity
}
Happy coding. If you are new to android you can also consider Kotlin.

public static final class RecentsViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
ImageView placeImage;
TextView placeName, countryName, price;
public RecentsViewHolder(#NonNull View itemView) {
super(itemView);
placeImage = itemView.findViewById(R.id.place_image);
placeName = itemView.findViewById(R.id.place_name);
countryName = itemView.findViewById(R.id.country_name);
price = itemView.findViewById(R.id.price);
itemView.setOnClickListener(this);
//you can do same code for another recyclerview.
}
#Override
public void onClick(View view) {
Intent intent = new Intent(context, Parlament.class);
view.getContext().startActivity(intent);
}
}

Download an image using Retrofit and Glide

I want to display images from https://picsum.photos/ into the imageView using recyclerView. Note that "https://picsum.photos/200" gets you a random square (200x200) image. I'm not sure if I'm using Glide and retrofit correctly (for arraylist with links it worked perfectly). I apriciate any hints. Thanks!
Edit: link to repo with all code: https://github.com/LightingTT/RecycleViewPictures
This is my ApiService:
public interface ApiService {
#GET("200/")
Call<List<Pictures>> getFile();
ApiClient:
public class ApiClient {
public static String BASE_URL = "https://picsum.photos/";
private static Retrofit retrofit;
public static Retrofit getClient(){
if(retrofit == null){
retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
return retrofit;
}
Object class:
public class Pictures {
#SerializedName("picture")
private String picturesUrl;
public Pictures (String picturesUrl)
{
this.picturesUrl = picturesUrl;
}
public String getImageUrl() {
return picturesUrl;
}
Adapter:
public class MyRecycleAdapter extends RecyclerView.Adapter<MyRecycleAdapter.ViewHolderClass> {
private static final String TAG = "MainActivity";
private Context context;
private List<Pictures> imageList;
//Constructor
public MyRecycleAdapter(Context context, List<Pictures> imageList)
{
this.context = context;
this.imageList = imageList;
}
//
public void setMyRecycleAdapter(List<Pictures> imageList)
{
this.imageList = imageList;
notifyDataSetChanged();
}
#NonNull
#Override
public ViewHolderClass onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.single_picture_view, parent, false);
ViewHolderClass linearViewHolderClass = new ViewHolderClass(view);
return linearViewHolderClass;
}
#Override
public void onBindViewHolder(#NonNull ViewHolderClass holder, int position) {
Glide
.with(context)
.load(imageList.get(position).getImageUrl())
.into(holder.imageView);
Log.d(TAG, "onBindViewHolder: ------>called<-----");
}
#Override
public int getItemCount() {
return imageList.size();
}
public class ViewHolderClass extends RecyclerView.ViewHolder{
private ImageView imageView;
//Constructor
public ViewHolderClass(#NonNull View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.single_picture_id);
}
}
And MainActivity:
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
MyRecycleAdapter recyclerAdapter;
List<Pictures> imageList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageList = new ArrayList<>();
//Create RecycleView object and pin view
RecyclerView recycleView = findViewById(R.id.linear_layout_with_recycleView_ID);
GridLayoutManager linearLayoutManager = new GridLayoutManager (this, 2);
//Setup Adapter
recycleView.setLayoutManager(linearLayoutManager);
recyclerAdapter = new MyRecycleAdapter(MainActivity.this, imageList);
recycleView.setAdapter(recyclerAdapter);
Log.d(TAG, "onCreate: ------>called<-----");
//Creating reference for MyService and receiving deserialized data.
ApiService apiClient = ApiClient.getClient().create(ApiService.class);
Call<List<Pictures>> call = apiClient.getFile();
call.enqueue(new Callback<List<Pictures>>() {
#Override
public void onResponse(Call<List<Pictures>> call, Response<List<Pictures>> response) {
imageList = response.body();
Log.d(TAG, "onResponse: ------>called<-----");
recyclerAdapter.setMyRecycleAdapter(imageList);
}
#Override
public void onFailure(Call<List<Pictures>> call, Throwable t) {
Log.d("TAG","onFailure = ------>called<----- "+t.toString());
}
});
}
}

It seems that I was asking wrong api. It should be
public interface ApiService {
#GET("/v2/list")
Call<List<Pictures>> getFile();
}
And object class was wrong. Generated by http://www.jsonschema2pojo.org/
public class Pictures {
#SerializedName("id")
#Expose
private String id;
#SerializedName("author")
#Expose
private String author;
#SerializedName("width")
#Expose
private Integer width;
#SerializedName("height")
#Expose
private Integer height;
#SerializedName("url")
#Expose
private String url;
#SerializedName("download_url")
#Expose
private String downloadUrl;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public Integer getWidth() {
return width;
}
public void setWidth(Integer width) {
this.width = width;
}
public Integer getHeight() {
return height;
}
public void setHeight(Integer height) {
this.height = height;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getDownloadUrl() {
return downloadUrl;
}
public void setDownloadUrl(String downloadUrl) {
this.downloadUrl = downloadUrl;
}
}
Now it works and displays nice random pictures in gridview.

Add to favorite using room Database

I'm referring this tutorial ==> https://uniqueandrocode.com/add-to-favourites-and-display-favourites-in-recyclerview/ in my project I have bottom navigation...I am trying to add favourites in the first tab and displaying favourites in the second tab in the bottom navigation bar. I'm using Room library.
When activity loads favourites are all blank at first, but when I first row as favourite and go-to favourite tab it displays properly but when I came back to the first tab it fills all the favourites icon automatically (which I have not done I had only done the first row)
Really need help. Thanks in advance.
Dao:
#Dao
public interface FavoriteDao {
#Insert
public void addData(FavoriteList favoriteList);
#Query("select * from favoritelist")
public List<FavoriteList> getFavoriteData();
#Query("SELECT EXISTS (SELECT 1 FROM favoritelist WHERE id=:id)")
public int isFavorite(int id);
#Delete
public void delete(FavoriteList favoriteList);
}
Database:
#Database(entities={FavoriteList.class},version = 1)
public abstract class FavoriteDatabase extends RoomDatabase {
public abstract FavoriteDao favoriteDao();
}
FavoriteList:
#Entity(tableName="favoritelist")
public class FavoriteList {
#PrimaryKey
private int id;
#ColumnInfo(name = "source")
private String source;
#ColumnInfo(name = "author")
private String author;
#ColumnInfo(name = "title")
private String title;
#ColumnInfo(name = "description")
private String description;
#ColumnInfo(name = "url")
private String url;
#ColumnInfo(name = "urlToImage")
private String urlToImage;
#ColumnInfo(name = "publishedAt")
private String publishedAt;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getSource() {
return source;
}
public void setSource(String source) {
this.source = source;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUrlToImage() {
return urlToImage;
}
public void setUrlToImage(String urlToImage) {
this.urlToImage = urlToImage;
}
public String getPublishedAt() {
return publishedAt;
}
public void setPublishedAt(String publishedAt) {
this.publishedAt = publishedAt;
}
}
News fragment:
public class news extends Fragment {
ImageView favbtn;
RecyclerView recyclerView;
SwipeRefreshLayout swipeRefreshLayout;
EditText etQuery;
Button btnSearch;
Adapter adapter;
List<Articles> articles = new ArrayList<>();
public static FavoriteDatabase favoriteDatabase;
public news() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_news, container, false);
swipeRefreshLayout = view.findViewById(R.id.swiprefresh);
etQuery = view.findViewById(R.id.etQuery);
btnSearch = view.findViewById(R.id.btnSearch);
favoriteDatabase= Room.databaseBuilder(getActivity(),FavoriteDatabase.class,"myfavdb").
allowMainThreadQueries().build();
recyclerView = view.findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
final String country = getCountry();
retrieveJson("", country, API_Key);
btnSearch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!etQuery.getText().toString().equals("")) {
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
retrieveJson(etQuery.getText().toString(), country, API_Key);
}
});
retrieveJson(etQuery.getText().toString(), country, API_Key);
} else {
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
retrieveJson("", country, API_Key);
}
});
retrieveJson("", country, API_Key);
}
}
});
return view;
}
private void showChangeLanguageDialog() {
}
public void retrieveJson(String query, String country, String apiKey) {
swipeRefreshLayout.setRefreshing(true);
Call<Headlines> call;
if (!etQuery.getText().toString().equals("")) {
call = ApiClient.getInstance().getApi().getSpecifiedData(query, apiKey);
} else {
call = ApiClient.getInstance().getApi().getHeadLines(country, apiKey);
}
call.enqueue(new Callback<Headlines>() {
#Override
public void onResponse(Call<Headlines> call, Response<Headlines> response) {
if (response.isSuccessful() && response.body().getArticles() != null) {
swipeRefreshLayout.setRefreshing(false);
// articles.clear();
articles = response.body().getArticles();
adapter = new Adapter(getContext(), articles);
recyclerView.setAdapter(adapter);
}
}
#Override
public void onFailure(Call<Headlines> call, Throwable t) {
swipeRefreshLayout.setRefreshing(false);
Toast.makeText(getContext(), t.getLocalizedMessage(), Toast.LENGTH_SHORT).show();
}
});
}
public String getCountry() {
Locale locale = Locale.getDefault();
String country = locale.getCountry();
return country.toLowerCase();
}
}
Adapter:
public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
Context context;
List<Articles> articles;
public Adapter(Context context, List<Articles> articles) {
this.context = context;
this.articles = articles;
}
#NonNull
#Override
public Adapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull final Adapter.ViewHolder holder, final int position) {
final Articles a = articles.get(position);
String imageUrl = a.getUrlToImage();
String url = a.getUrl();
holder.tvTitle.setText(a.getTitle());
Picasso.get().load(imageUrl).into(holder.imageView);
holder.tvSource.setText(a.getSource().getName());
holder.tvDate.setText(dateTime(a.getPublishedAt()));
holder.cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context,DetailedActivity.class);
intent.putExtra("title",a.getTitle());
intent.putExtra("source",a.getSource().getName());
intent.putExtra("time",dateTime(a.getPublishedAt()));
intent.putExtra("desc",a.getDescription());
intent.putExtra("imageUrl",a.getUrlToImage());
intent.putExtra("url",a.getUrl());
context.startActivity(intent);
}
});
if (news.favoriteDatabase.favoriteDao().isFavorite(articles.get(position).getId())==1)
holder.bookmark.setImageResource(R.drawable.ic_bookmark);
else
holder.bookmark.setImageResource(R.drawable.ic_baseline_bookmark_border_24);
holder.bookmark.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FavoriteList favoriteList = new FavoriteList();
int id = articles.get(position).getId();
String source = articles.get(position).getSource().getName();
String author = articles.get(position).getAuthor();
String publishedAt = articles.get(position).getPublishedAt();
String description = articles.get(position).getDescription();
String title = articles.get(position).getTitle();
String url = articles.get(position).getUrl();
String urlToImage = articles.get(position).getUrlToImage();
favoriteList.setId(id);
favoriteList.setAuthor(author);
favoriteList.setDescription(description);
favoriteList.setSource(source);
favoriteList.setPublishedAt(publishedAt);
favoriteList.setTitle(title);
favoriteList.setUrl(url);
favoriteList.setUrlToImage(urlToImage);
favoriteList.setPublishedAt(dateTime(articles.get(position).getPublishedAt()));
if (news.favoriteDatabase.favoriteDao().isFavorite(id)!=1){
holder.bookmark.setImageResource(R.drawable.ic_bookmark);
news.favoriteDatabase.favoriteDao().addData(favoriteList);
}else {
holder.bookmark.setImageResource(R.drawable.ic_baseline_bookmark_border_24);
news.favoriteDatabase.favoriteDao().delete(favoriteList);
}
}
});
}
#Override
public int getItemCount() {
return articles.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView tvTitle, tvSource, tvDate;
ImageView imageView;
ImageButton bookmark;
CardView cardView;
public ViewHolder(#NonNull View itemView) {
super(itemView);
tvTitle = itemView.findViewById(R.id.tvId);
tvSource = itemView.findViewById(R.id.tvSource);
tvDate = itemView.findViewById(R.id.tvDate);
imageView = itemView.findViewById(R.id.image);
cardView = itemView.findViewById(R.id.cardView);
bookmark = itemView.findViewById(R.id.favrr);
}
}

Steps to debug:
Add 2-3 items as Favs.
Restart the Application.
Check if it shows those items as fav after restarting application .
also add logs to those if conditions where you are changing the drawables.
After looking at your JSON it looks like id is what creating problems. Id is null for all your json items so when fav. one it shows fav. to all.
Solution : Use another field to check if the data is added to fav.list
Delete will not work either
Try
#Query("DELETE FROM favoritelist WHERE title = :title")
void deleteByUserId(String title);
To delete item
Also https://github.com/amitshekhariitbhu/Android-Debug-Database
check this library to debug your database

Data from Firebase did not show in RecyclerView

My RecyclerView not show any data from Firebase. I don't see any errors at logcat so I don't know why. I followed guide from youtube video. But still nothing. I'm using android 8.0 and API 27. Hope Somebody can help.
My Main Activity Code:
public class ViewProduct extends AppCompatActivity {
DatabaseReference ref;
ArrayList<Model> list;
private RecyclerView recyclerView;
private RecyclerView.Adapter viewHolder;
private RecyclerView.LayoutManager layoutManager;
SearchView searchView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_product) ;
ref = FirebaseDatabase.getInstance().getReference().child("buddymealplanneruser").
child("Products");
recyclerView = findViewById(R.id.stallproductRecyclerView);
//recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
//SEARCH VIEW
searchView = findViewById(R.id.searchProductStall);
//ADAPTER
list = new ArrayList<>();
viewHolder = new ViewHolder(list);
recyclerView.setAdapter(viewHolder);
}
#Override
protected void onRestart() {
super.onRestart();
if (ref!=null)
{
ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists())
{
//list = new ArrayList<>();
list.clear();
for(DataSnapshot ds : dataSnapshot.getChildren())
{
list.add(ds.getValue(Model.class));
}
//ViewHolder viewHolder = new ViewHolder(list);
//recyclerView.setAdapter(viewHolder);
viewHolder.notifyDataSetChanged();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(ViewProduct.this, databaseError.getMessage(),
Toast.LENGTH_SHORT).show();
}
});
}
if (searchView !=null)
{
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String s)
{
return false;
}
#Override
public boolean onQueryTextChange(String s) {
search(s);
return true;
}
});
}
}
private void search(String str) {
ArrayList<Model> myList = new ArrayList<>();
for(Model object : list)
{
if(object.getProductName().toLowerCase().contains(str.toLowerCase()))
{
myList.add(object);
}
}
ViewHolder viewHolder = new ViewHolder(myList);
recyclerView.setAdapter(viewHolder);
}
}
My Adapter:
public class ViewHolder extends RecyclerView.Adapter<ViewHolder.MyViewHolder> {
ArrayList<Model> list;
public ViewHolder (ArrayList<Model> list)
{
this.list=list;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row_product, viewGroup,false);
return new MyViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder myViewHolder, int i) {
myViewHolder.productName.setText(list.get(i).getProductName());
myViewHolder.productCalorie.setText(list.get(i).getProductCalorie());
myViewHolder.StallId.setText(list.get(i).getStallId());
myViewHolder.productType.setText(list.get(i).getProductType());
myViewHolder.productServing.setText(list.get(i).getProductServing());
myViewHolder.statusProduct.setText(list.get(i).getStatusProduct());
}
#Override
public int getItemCount()
{
return list.size();
}
class MyViewHolder extends RecyclerView.ViewHolder
{
TextView productName, productCalorie, StallId;
TextView productType, productServing, statusProduct;
ImageView productImageView;
public MyViewHolder (#NonNull View itemView){
super((itemView));
productName = itemView.findViewById(R.id.productTitle);
productCalorie = itemView.findViewById(R.id.productDescriptionCalorie);
StallId = itemView.findViewById(R.id.productDescriptionStallId);
productType = itemView.findViewById(R.id.productDescriptionType);
productServing=itemView.findViewById(R.id.productDescriptionServing);
statusProduct=itemView.findViewById(R.id.productDescriptionAvailibility);
//productImageView = itemView.findViewById(R.id.productImageView);
}
}
}
My Model :
package com.example.buddymealplannerstall.Child;
import android.view.Display;
public class Model {
//String productName, productImage, productCalorie, StallId, productType, productServing, statusProduct;
private String StallId;
private String productCalorie;
private String productImage;
private String productName;
private String productServing;
private String productType;
private String statusProduct;
public Model (String StallId,
String productCalorie,
String productImage,
String productName,
String productServing,
String productType,
String statusProduct){
this.StallId = StallId;
this.productCalorie = productCalorie;
this.productImage = productImage;
this.productName = productName;
this.productServing = productServing;
this.productType = productType;
this.statusProduct = statusProduct;
}
public Model(){
}
public String getStallId() {
return StallId;
}
public void setStallId(String stallId) {
StallId = stallId;
}
public String getProductCalorie() {
return productCalorie;
}
public void setProductCalorie(String productCalorie) {
this.productCalorie = productCalorie;
}
public String getProductImage() {
return productImage;
}
public void setProductImage(String productImage) {
this.productImage = productImage;
}
public String getProductName() {
return productName;
}
public void setProductName(String productName) {
this.productName = productName;
}
public String getProductServing() {
return productServing;
}
public void setProductServing(String productServing) {
this.productServing = productServing;
}
public String getProductType() {
return productType;
}
public void setProductType(String productType) {
this.productType = productType;
}
public String getStatusProduct() {
return statusProduct;
}
public void setStatusProduct(String statusProduct) {
this.statusProduct = statusProduct;
}
}
Screen Shot of my firebase and my apps.
firebase
my app

According to your comment:
yes, buddymealplanner is my project's name
Please note that there is no need to add the name of your project as a child in the reference. So please change the following line of code:
ref = FirebaseDatabase.getInstance().getReference().child("buddymealplanneruser").
child("Products");
Simply to:
ref = FirebaseDatabase.getInstance().getReference().child("Products");

I dont think you are populating your list, you are sending it empty. From what I can see, you only add items to the list when you are restarting the activity. Try either populating it before sendinig the list, or changing the onRestart() for an onStart() or an onResume().

JSON parse android with Retrofit [duplicate]

This question already has an answer here:
Android - null object reference when iterating List
(1 answer)
Closed 5 years ago.
i want parse json with retrofit2 but my code dose not work
this web service is:(please check the webservice):
http://services.groupkt.com/country/search?text=
this is my model class:
public class Country {
#SerializedName("name")
#Expose
private String name;
#SerializedName("alpha2_code")
#Expose
private String alpha2Code;
#SerializedName("alpha3_code")
#Expose
private String alpha3Code;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAlpha2Code() {
return alpha2Code;
}
public void setAlpha2Code(String alpha2Code) {
this.alpha2Code = alpha2Code;
}
public String getAlpha3Code() {
return alpha3Code;
}
public void setAlpha3Code(String alpha3Code) {
this.alpha3Code = alpha3Code;
}
}
And:
public class CountryResponse {
#SerializedName("messages")
#Expose
private List<String> messages = null;
#SerializedName("result")
#Expose
private List<Country> countryList = null;
public List<String> getMessages() {
return messages;
}
public void setMessages(List<String> messages) {
this.messages = messages;
}
public List<Country> getCountryList() {
return countryList;
}
public void setCountryList(List<Country> countryList) {
this.countryList = countryList;
}
}
And:
public class Example {
#SerializedName("RestResponse")
#Expose
private CountryResponse restResponse;
public CountryResponse getRestResponse() {
return restResponse;
}
public void setRestResponse(CountryResponse restResponse) {
this.restResponse = restResponse;
}
}
And this is my interface class:
public interface APIInterface {
#GET("search?text=")
Call<Example> getCountries();
}
And i write 2 classes for return retrofit object:
public class APIClient {
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;
}
}
public class APIUtils {
public static final String BASE_URL =
"http://services.groupkt.com/country/";
public static APIInterface getSOService() {
return APIClient.getClient(BASE_URL).create(APIInterface.class);
}
}
My Adapter:
public class ResponseAdapter extends
RecyclerView.Adapter<ResponseAdapter.ViewHolder> {
private List<Example> mItems;
private Context mContext;
Example example;
CountryResponse countyResponse;
public ResponseAdapter(Context context, Example example) {
this.example = example;
mContext = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.item_list, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Example example = mItems.get(position);
TextView textView = holder.name;
textView.setText(example.getRestResponse()
.getCountryList().get(position).getName());
TextView textView1 = holder.alpha;
textView1.setText(example.getRestResponse().
getCountryList().get(position).getAl
pha2Code());
TextView textView2 = holder.alpha2;
textView2.setText(example.getRestResponse().
getCountryList().get(position).getAl
pha3Code());
}
#Override
public int getItemCount() {
return mItems.size();
}
public void updateAnswers(CountryResponse countryRes) {
countyResponse = countryRes;
notifyDataSetChanged();
}
private Example getItem(int adapterPosition) {
return mItems.get(adapterPosition);
}
public interface PostItemListener {
void onPostClick(long id);
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView name, alpha, alpha2;
public ViewHolder(View itemView) {
super(itemView);
name = (TextView) itemView.findViewById(R.id.name);
alpha = (TextView) itemView.findViewById(R.id.alpha);
alpha2 = (TextView) itemView.findViewById(R.id.alpha2);
}
}
}
And My Activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_response);
apiInterface= APIUtils.getSOService();
mRecyclerView= (RecyclerView) findViewById(R.id.my_recycler_view);
mAdapter=new ResponseAdapter(this,new Example());
RecyclerView.LayoutManager layoutManager = new
LinearLayoutManager(this);
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setHasFixedSize(true);
loadAnswers();
}
private void loadAnswers() {
apiInterface.getCountries().enqueue(new Callback<Example>() {
#Override
public void onResponse(Call<Example> call, Response<Example>
response) {
mAdapter.updateAnswers(response.body().getRestResponse());
}
#Override
public void onFailure(Call<Example> call, Throwable t) {
}
});
}
when run a error showing that
'java.util.Iterator java.util.List.iterator()' on a null object reference

You have
#Override
public int getItemCount() {
return mItems.size();
}
public void updateAnswers(CountryResponse countryRes) {
countyResponse = countryRes;
notifyDataSetChanged();
}
Your List is not initialized in the first place. Secondly you need to populate your List with items. And your list must be Country list not of type Example
You need to change to
public void updateAnswers(CountryResponse countryRes) {
mItems.addAll(countryRes.getCountryList())
notifyDataSetChanged();
}
And also initialize the list
List<Country> mItems = new ArrayList();
// note its of type Country not of Example
Finally update your views accordingly in onBindViewHolder
textView.setText(mItems.get(position).getName());
textView1.setText(mItems.get(position).getAlpha2Code());
textView2.setText(mItems.get(position).getAlpha3Code());