Develop Reference

How to fetch link from json and connect it to button?

I am working with a project and I am trying to fetch some link from a json data and I want to connect the link with a button in my recycleview so that whenever the button is clicked, it'll automatically connet to the respective websites. I gave user permission to interner in Manifest. So, How to connect it?
package com.example.covidcuretemplate1;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private RequestQueue requestQueue;
private ExampleAdapter exampleAdapter;
private ArrayList<ExampleItem> exampleList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this, RecyclerView.HORIZONTAL,false));
exampleList = new ArrayList<>();
requestQueue = Volley.newRequestQueue(this);
parseJSON();
}
private void parseJSON() {
String url = "https://newsapi.org/v2/top-headlines?country=in&category=health&apiKey=*************************";
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
JSONArray jsonArray = response.getJSONArray("articles");
for(int i = 0; i < jsonArray.length(); i++)
{
JSONObject article = jsonArray.getJSONObject(i);
if(article.isNull("description") || article.isNull("urlToImage")) {
continue;
}
if(article.getString("description").isEmpty() || article.getString("urlToImage").isEmpty())
continue;
String title = article.getString("title");
String description = article.getString("description");
String date = article.getString("publishedAt");
String imageurl = article.getString("urlToImage");
//How to connect this??????
String newsurl = article.getString("url");
exampleList.add(new ExampleItem(imageurl,title,description,date));
}
exampleAdapter = new ExampleAdapter(MainActivity.this,exampleList);
recyclerView.setAdapter(exampleAdapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
});
requestQueue.add(request);
}
}
My Adapter class, Here can anybody suggest anything in the place of toast? The Toast is working fine !!!
public class ExampleAdapter extends RecyclerView.Adapter<ExampleAdapter.ExampleViewHolder> {
public Context mcontext;
public ArrayList<ExampleItem> marrayList;
public ExampleAdapter(Context mcontext, ArrayList<ExampleItem> marrayList) {
this.mcontext = mcontext;
this.marrayList = marrayList;
}
#NonNull
#Override
public ExampleViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(mcontext).inflate(R.layout.card_item,parent,false);
ExampleViewHolder exampleViewHolder = new ExampleViewHolder(view);
return exampleViewHolder;
}
#Override
public void onBindViewHolder(#NonNull ExampleViewHolder holder, int position) {
ExampleItem examplItem = marrayList.get(position);
String imageurl = examplItem.getMimgurl();
String title = examplItem.getMtitle();
String description = examplItem.getMdescription();
String date = examplItem.getMdate();
/////////////
final String newsurl = examplItem.getMurl();
////////////
holder.textview_title.setText(title);
holder.textview_description.setText(description);
holder.textview_date.setText(date);
Glide.with(mcontext).load(imageurl).into(holder.imageview_news);
///////////////////////////
holder.button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//////////////////////////////////NEED HELP!!!!!!!!!!!!!!!!!!/////////
Toast.makeText(mcontext,newsurl,Toast.LENGTH_LONG).show();
}
});
//////////////////////////
}
#Override
public int getItemCount() {
return marrayList.size();
}
public static class ExampleViewHolder extends RecyclerView.ViewHolder{
public ImageView imageview_news;
public TextView textview_title;
public TextView textview_description;
public TextView textview_date;
///////////////////////////
public Button button;
///////////////////////////
public ExampleViewHolder(#NonNull View itemView) {
super(itemView);
imageview_news = itemView.findViewById(R.id.imageview_news);
textview_title = itemView.findViewById(R.id.textview_title);
textview_description = itemView.findViewById(R.id.textview_description);
textview_date = itemView.findViewById(R.id.textview_date);
/////////////////////////
button = itemView.findViewById(R.id.button);
////////////////////////
}
}
}

Try to set intent for the website inside the onClickListener. Something like this:
Button button= findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String url = "http://www.YourWebsite.com"; //insert the link you prase
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse(url));
startActivity(intent);
}
});

You can use this code inside onClickListener to open it in the browser.
Uri uri = Uri.parse(newsurl);
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);

Array list size always 0, even after add data to it

I want to display what my array list value is. So, I want to loop with the size of array list as the limit. But after I add some value through a function, and want to get the size of it, it always 0. I still newbie in android programming. I had search in google, but still confused and not understand what the problem is. Thanks for you guys help
I had tried to set through global variable, but it's not work
Here is my activity file
package bobby.irawan.aticket;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.w3c.dom.Text;
import java.util.ArrayList;
import java.util.List;
public class DetailPromoActivity extends AppCompatActivity {
private ListView listView;
private TextView nama_detail_promo_tv;
private String nama_detail_promo;
private DetailPromoAdapter adapter;
private int counter_header=0, counter_promo = 0;
private View layout_kupon;
private int id_link_promo;
private RequestQueue requestQueue;
private String url = "192.168.11.134:8000";
private TextView header_promo, kupon_promo, notif_promo;
private ArrayList<DetailPromo> detailPromos;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail_promo);
View view = findViewById(R.id.layout_kupon);
header_promo = view.findViewById(R.id.header_promo_tv);
kupon_promo = view.findViewById(R.id.kode_promo_tv);
id_link_promo = (int) getIntent().getSerializableExtra("id_promo");
nama_detail_promo = (String) getIntent().getSerializableExtra("nama_promo");
String nama_ota = (String) getIntent().getSerializableExtra("nama_ota");
listView = findViewById(R.id.lv_detpro);
layout_kupon = findViewById(R.id.layout_kupon);
header_promo = layout_kupon.findViewById(R.id.header_promo_tv);
kupon_promo = layout_kupon.findViewById(R.id.kode_promo_tv);
notif_promo = layout_kupon.findViewById(R.id.notif_promo_tv);
requestQueue = Volley.newRequestQueue(this);
nama_detail_promo_tv = findViewById(R.id.nama_detail_promo);
nama_detail_promo_tv.setText(nama_detail_promo);
setDetailPromotoClass(id_link_promo);
adapter = new DetailPromoAdapter(detailPromos,this);
listView.setAdapter(adapter);
adapter.notifyDataSetChanged();
ActionBar actionBar = getSupportActionBar();
actionBar.setTitle("Promo "+nama_ota);
actionBar.setHomeButtonEnabled(true);
actionBar.setDisplayHomeAsUpEnabled(true);
//Set kupon
System.out.println("Size detpro "+counter_header+" "+counter_promo);
if(counter_header == 0 && counter_promo == 0){
notif_promo.setVisibility(View.VISIBLE);
header_promo.setVisibility(View.GONE);
kupon_promo.setVisibility(View.GONE);
System.out.println("Masuk sini");
}
else if(counter_header == 0){
header_promo.setText("PROMO PESAWAT");
}
else{
kupon_promo.setText("Tidak perlu");
}
}
class DetailPromoAdapter extends BaseAdapter {
private List<DetailPromo> detailPromo;
private Context context;
public DetailPromoAdapter(List<DetailPromo> detailPromo, Context context) {
this.detailPromo = detailPromo;
this.context = context;
}
#Override
public int getCount() {
System.out.println("Detail promo size"+detailPromo.size());
return detailPromo.size();
}
#Override
public Object getItem(int position) {
return null;
}
#Override
public long getItemId(int position) {
return 0;
}
#NonNull
#Override
public View getView(int position, View convertView, ViewGroup parent) {
convertView = getLayoutInflater().inflate(R.layout.detail_promo_adapter, parent, false);
TextView nama_detail_promo = convertView.findViewById(R.id.isi_detail_promo);
if(detailPromo.get(position).getDetpro_role().equals("detail_promo")){
nama_detail_promo.setText(detailPromo.get(position).getDetpro_list());
}
return convertView;
}
}
public void setDetailPromotoClass(int id_linkpro){
detailPromos = new ArrayList<DetailPromo>();
String url_promo = "http://"+url+"/detail_promo/"+id_linkpro;
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url_promo, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
JSONArray jsonArray = response.getJSONArray("data");
for(int i=0; i<jsonArray.length(); i++){
JSONObject data_promo = jsonArray.getJSONObject(i);
int id_detpro = data_promo.getInt("id");
int id_promo = data_promo.getInt("promo_id");
int id_linkpro = data_promo.getInt("linkpro_id");
String detpro_list = data_promo.getString("detpro_list");
String detpro_role = data_promo.getString("detpro_role");
detailPromos.add(new DetailPromo(id_detpro,id_promo,id_linkpro,detpro_list,detpro_role));
System.out.println("Data promo yang diklik "+id_promo+" "+id_linkpro+" "+detpro_list+" "+detpro_role);
adapter.notifyDataSetChanged();
if(detpro_role.equals("header_promo")){
header_promo.setText(detailPromos.get(i).detpro_list);
System.out.println("Ada header");
counter_header++;
}
if(detpro_role.equals("kode_promo")){
System.out.println("Ada kupon");
kupon_promo.setText(detailPromos.get(i).detpro_list);
counter_promo++;
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
});
requestQueue.add(request);
}
}

Unable to make CustomAdapter work in a Loop using Fragments

I'm trying to fill make the data show in my Listview, however when i click on the fragment there is nothing on the list.
I've tried move the setAdapter inside the loop but it did not work.
I'm running out of ideas about how to make it work
Has anybody tried to fill an custom adapter with fragments before???
This is my Custom Adapter
import android.content.Context;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.List;
/**
* Created by calvi on 22/05/2018.
*/
public class MyListAdapter extends ArrayAdapter<User> {
List<User> userList;
Context context;
int resource;
public MyListAdapter(#NonNull Context context, #LayoutRes int resource, List<User> userList) {
super(context, resource, userList);
this.context = context;
this.resource = resource;
this.userList = userList;
}
#NonNull
#Override
public View getView(final int position, #Nullable View convertView, #NonNull ViewGroup parent) {
//And for this we need a layoutinflater
LayoutInflater layoutInflater = LayoutInflater.from(context);
Log.d("listando", "Antes do inflater");
//getting the view
View view = layoutInflater.inflate(resource, null, false);
Log.d("listando", "Depois do inflater");
//getting the view elements of the list from the view
TextView textViewName = view.findViewById(R.id.list_row);
Log.d("listando", "Depois de pegar o textview");
//getting the hero of the specified position
User user = userList.get(position);
Log.d("listando", "Depois de pegar o get pisition");
//adding values to the list item
textViewName.setText(user.getName());
Log.d("listando", "Depois de setar o name");
//finally returning the view
return view;
}
}
And this is my Fragment which are taking data from firebase and populating it on the adapter
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.GenericTypeIndicator;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
public class UserMessageListFragment extends Fragment {
private ProgressDialog progressDialog;
private final String TAG = "UsersMessageLis";
private ArrayList<String> arrayList = new ArrayList<>();
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
private int totalUsers = 0;
private ListView listView;
private TextView noUsersText;
private List<User> userList = new ArrayList<>();
public static UserMessageListFragment newInstance() {
return new UserMessageListFragment();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_user_message_list, container, false);
listView = view.findViewById(R.id.usersListListView);
noUsersText = view.findViewById(R.id.noUsersText);
final DatabaseReference refMessages = FirebaseDatabase.getInstance().getReference();
final DatabaseReference ref= FirebaseDatabase.getInstance().getReference().child("usuarios");
refMessages.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
if(dataSnapshot.getKey().contains(UserDetails.username+ "_")) {
final String[] userChatWithId = dataSnapshot.getKey().split(UserDetails.username+"_");
ref.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
if(dataSnapshot.getKey().equals(userChatWithId[1])) {
GenericTypeIndicator<Map<String, String>> genericTypeIndicator = new GenericTypeIndicator<Map<String, String>>() {};
Map<String, String> map = dataSnapshot.getValue(genericTypeIndicator);
String name = map.get("name").toString();
String username = map.get("username").toString();
String status = map.get("status").toString();
String city = map.get("city").toString();
Log.d("listando", name);
Log.d("listando", username);
Log.d("listando", status);
Log.d("listando", city);
User newUser = new User(username, status, city, name);
Log.d("Listando", newUser.toString());
userList.add(newUser);
//// usersList.setAdapter(new ArrayAdapter<>(getContext(), R.layout.my_list, arrayList));
}
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
MyListAdapter adapter = new MyListAdapter(getContext(), R.layout.my_list, userList);
//attaching adapter to the listview
listView.setAdapter(adapter);
// listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
// #Override
// public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// UserDetails.chatWithId = arrayList.get(position);
// startActivity(new Intent(getContext(), Chat.class));
// }
// });
return view;
}
// public void doOnSuccess(String response) {
//
// try {
// JSONObject object = new JSONObject(response);
// Iterator iterator = object.keys();
// String key = "";
//
// while(iterator.hasNext()) {
// key = iterator.next().toString();
//
// if(! key.equals(UserDetails.username)) {
// arrayList.add(key);
// }
// totalUsers++;
// }
//
// } catch (JSONException e) {
// e.printStackTrace();
// }
//
// checkIfThereIsAnUser(totalUsers);
// }
// public void checkIfThereIsAnUser(int totalUsers) {
//
//
// if(totalUsers <=1){
// noUsersText.setVisibility(View.VISIBLE);
// usersList.setVisibility(View.GONE);
// }
// else{
// noUsersText.setVisibility(View.GONE);
// usersList.setVisibility(View.VISIBLE);
// usersList.setAdapter(new ArrayAdapter<>(getContext(), R.layout.my_list, arrayList));
// }
// progressDialog.dismiss();
// }
}
What i have noticed is that the logs inside the adapter are not showing

When you create adapter
MyListAdapter adapter = new MyListAdapter(getContext(), R.layout.my_list, userList);
the userList is empty. So when you add an item to userList, you have to adapter.notifyDataSetChange() to update your adapter

Try refMessages.addChildEventListener(getActivity(),new ChildEventListener() {......}
Do this in every listeners if they are in fragments.
In case of an Activity you don't need to do this.

ReyclerView. Police Data Json - No adapter attached, skipping layout

Good afternoon guys, I am trying to fetch some data from the police data website.
Unfortunately, the application doesn't show any data saying "E/RecyclerView: No adapter attached; skipping layout".
I have attached the LatestCrimesActivity, adapter and the ListItem class.
Thank you for your help.
This is LatestCrimesActivity:
package com.example.cosmin.crimerate.Latest_crimes_api;
import android.app.ProgressDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.example.cosmin.crimerate.R;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class LatestCrimesActivity extends AppCompatActivity {
private static final String URL_DATA = "https://data.police.uk/api/crimes-street/all-crime?poly=52.268,0.543:52.794,0.238:52.130,0.478&date=2017-01";
private RecyclerView recyclerView;
private RecyclerView.Adapter adapter;
private List<ListItem> listItems;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_latest_crimes);
recyclerView = (RecyclerView) findViewById(R.id.recyclerViewlatest);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
listItems=new ArrayList<>();
loadRecyclerViewData();
}
private void loadRecyclerViewData() {
final ProgressDialog progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Loading data...");
progressDialog.show();
StringRequest stringRequest = new StringRequest(Request.Method.GET,
URL_DATA,
new Response.Listener<String>() {
#Override
public void onResponse(String s) {
progressDialog.dismiss();
try {
JSONObject jsonObject = new JSONObject(s);
JSONArray array = jsonObject.getJSONArray("");
for (int i=0; i<array.length();i++){
JSONObject o = array.getJSONObject(i);
ListItem item = new ListItem(
o.getString("category"),
o.getString("location_type"),
o.getString("street"),
o.getString("status")
);
listItems.add(item);
}
adapter = new MyAdapter(listItems, getApplicationContext());
recyclerView.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError volleyError) {
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
}
}
Adapter:
package com.example.cosmin.crimerate.Latest_crimes_api;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.TextView;
import com.example.cosmin.crimerate.R;
import java.util.List;
/**
* Created by Cosmin on 25/11/2017.
*/
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<ListItem> listItems;
private Context context;
public MyAdapter(List<ListItem> listItems, LatestCrimesActivity latestCrimesActivity) {
this.listItems = listItems;
this.context = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item, parent, false);
return new ViewHolder(v);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
ListItem listItem = listItems.get(position);
holder.textViewCat.setText(listItem.getCategory());
holder.textViewLoc.setText(listItem.getLocation());
holder.textViewStreet.setText(listItem.getStreet());
holder.textViewStatus.setText(listItem.getStatus());
}
#Override
public int getItemCount() {
return listItems.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
public TextView textViewCat;
public TextView textViewLoc;
public TextView textViewStreet;
public TextView textViewStatus;
public ViewHolder(View itemView) {
super(itemView);
textViewCat = (TextView) itemView.findViewById(R.id.textViewCat);
textViewLoc = (TextView) itemView.findViewById(R.id.textViewLoc);
textViewStreet = (TextView) itemView.findViewById(R.id.textViewStreet);
textViewStatus = (TextView) itemView.findViewById(R.id.textViewStatus);
}
}
}
This is ListItem class:
package com.example.cosmin.crimerate.Latest_crimes_api;
/**
* Created by Cosmin on 25/11/2017.
*/
public class ListItem {
private String category;
private String location;
private String street;
private String status;
public ListItem (String category, String location, String street, String status){
this.category=category;
this.location=location;
this.street=street;
this.status=status;
}
public String getCategory (){
return category;
}
public String getLocation (){
return location;
}
public String getStreet (){
return street;
}
public String getStatus (){
return status;
}
}

Just try to change some lines. First set adapter before your api call.
recyclerView = (RecyclerView) findViewById(R.id.recyclerViewlatest);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
listItems=new ArrayList<>();
adapter = new MyAdapter(listItems, getApplicationContext());
recyclerView.setAdapter(adapter);
Then when you received the answer, fill listItems, then call notifyDataSetChange() method of your adapter object.

Android Recycler View caching

I'm using volley to load data using JSON Parsing in to a recycler view. I've used recylcer view before, but somehow, the downloaded data is persistent this time, meaning its still there after the app is closed, maybe stays in cache. I'm not sure, what I'm doing wrong here. Any help is appreciated, thanks.
Edit: The application is storing downloaded data after the app is closed, which doesn't happen when using recycler view.
This is my Activity Class:
package com.example.recyclerview;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class PostActivity extends AppCompatActivity implements
OnItemClick{
private ArrayList<PostData> posts = new ArrayList<>();
private PostRecycleViewAdapter viewAdapter;
private String listingJsonUrl = "https://jsonplaceholder.typicode.com/posts/";
Toolbar toolbar;
private ProgressDialog progressDialog;
private RequestQueue requestQueue;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
progressDialog = new ProgressDialog(this);
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.setCancelable(true);
final RecyclerView.LayoutManager viewLayoutManager = new LinearLayoutManager(getApplicationContext());
viewAdapter = new PostRecycleViewAdapter(posts);
final RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(viewLayoutManager);
recyclerView.setAdapter(viewAdapter);
viewAdapter.setClickListener(this);
new DownloadData().execute(listingJsonUrl);
}
#Override
public void onClick(View view, int position) {
final PostData data = posts.get(position);
String title;
int id;
Intent commentIntent = new Intent(this, CommentsActivity.class);
id = data.getId();
title = data.getTitle();
if(title.length() > 25){
title = title.substring(0,25);
title = title.concat("..");
}
commentIntent.putExtra("title",title) ;
commentIntent.putExtra("id", id);
startActivity(commentIntent);
}
class DownloadData extends AsyncTask<String, String, String>{
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
}
#Override
protected String doInBackground(String... url) {
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, url[0], new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
try {
JSONArray jsonArray = new JSONArray(response.toString());
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
PostData postData = new PostData(jsonObject.getInt("id"),jsonObject.getString("title"), jsonObject.getString("body"));
posts.add(postData);
viewAdapter.notifyDataSetChanged();
}
}
catch (JSONException e)
{
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.d("JsonError", error.getMessage());
}
});
getRequestQueue().add(jsonArrayRequest);
return null;
}
}
public RequestQueue getRequestQueue()
{
if (requestQueue == null)
{
requestQueue = com.android.volley.toolbox.Volley.newRequestQueue(getApplicationContext());
}
return requestQueue;
}
}
This is my RecyclerView Adapter Class:
package com.example.recyclerview;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.List;
public class PostRecycleViewAdapter extends RecyclerView.Adapter<PostRecycleViewAdapter.ViewHolder>
{
private List<PostData> postData;
private OnItemClick itemClick;
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
public TextView title, body;
public ViewHolder(View view){
super(view);
title = (TextView) view.findViewById(R.id.title);
body = (TextView) view.findViewById(R.id.body);
view.setTag(view);
view.setOnClickListener(this);
}
#Override
public void onClick(View view) {
if(itemClick != null) itemClick.onClick(view, getAdapterPosition());
}
}
public PostRecycleViewAdapter(List<PostData> postData)
{
this.postData = postData;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemLayout = LayoutInflater.from(parent.getContext()).inflate(R.layout.post_recycler_view,parent,false);
return new ViewHolder(itemLayout);
}
#Override
public void onBindViewHolder(PostRecycleViewAdapter.ViewHolder holder, int position) {
PostData data = postData.get(position);
holder.title.setText(data.getTitle());
holder.body.setText(data.getBody());
}
#Override
public int getItemCount() {
return postData.size();
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);}
public void setClickListener(OnItemClick itemClick) {
this.itemClick = itemClick;
}
}
And this is the data item class:
package com.example.recyclerview;
public class PostData {
private String title, body;
private int id;
public PostData(int id, String title, String body)
{
this.id = id;
this.title = title;
this.body = body;
}
public String getTitle() {
return title;
}
public String getBody() {
return body;
}
public int getId() {
return id;
}
}