RecyclerView in FragmentPagerAdapater in Activity

Question

When I arrive in my Activity, I call a FragmentPagerAdapter to handle my differents tabs. In one of my tabs, I want to show a RecyclerView, but he never show up, with the breakpoint, I saw that the application handle everything. So I don't know where to look.

This is my activity :

public class InfoClient extends AppCompatActivity implements Response.ErrorListener, Response.Listener<String> {
    TextView tv_client = null;
    RequestQueue queue;
    String url;
    StringRequest stringRequest;
    ViewPager viewPager;
    TabLayout tabLayout;
    ViewPagerAdapter viewPagerAdapter;

    String nomClient;
    String adresseClient;
    String codePostalClient;
    String villeClient;
    String telClient;





    private Toolbar toolbar;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_info_client);
        viewPager=findViewById(R.id.viewPager);
        Bundle extras = getIntent().getExtras();
       String leclient = (String) extras.get("leClient");
       queue = Volley.newRequestQueue(InfoClient.this);
       url = "http://myip:80/select/infoClient/"+leclient;
       stringRequest = new StringRequest(GET, url, InfoClient.this, InfoClient.this);
       queue.add(stringRequest);

    }


    @Override
    public void onErrorResponse(VolleyError error) {

    }


    @Override
    public void onResponse(String response) {


        try{


            JSONObject client = new JSONObject(response);

            String idClient = client.get("CLCLEUNIK").toString();
            String nomClient = client.get("NOM").toString();
            String adresseClient = client.get("ADRESSE").toString();
            String codePostalClient = client.get("CODEP").toString();
            String villeClient = client.get("VILLE").toString();
            String telClient = client.get("TEL").toString();




            viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
            viewPagerAdapter.addClient(idClient,nomClient,adresseClient,codePostalClient,villeClient,telClient);
            viewPager.setAdapter(viewPagerAdapter);

            tabLayout=findViewById(R.id.tabs);


            tabLayout.setupWithViewPager(viewPager);




        }catch (JSONException e) {
            e.printStackTrace();
        }

    }
}

This is my FragmentPagerAdapter :

public class ViewPagerAdapter extends FragmentPagerAdapter {

    RequestQueue queue;
    private String idClient;
    private String nomClient;
    private String adresseClient;
    private String codePostalClient;
    private String villeClient;
    private String telClient;

    private String[] libelle = { "Coordonnées", "Contacts", "TI" };

    public void addClient (String p_idClient,String p_nomclient, String p_adresseClient, String p_codePostalClient, String p_villeClient, String p_telClient) {
        idClient=p_idClient;
        nomClient=p_nomclient;
        adresseClient=p_adresseClient;
        codePostalClient=p_codePostalClient;
        villeClient=p_villeClient;
        telClient=p_telClient;

    }

        ViewPagerAdapter(@NonNull FragmentManager fm) {
            super(fm);
        }

        @NonNull
        @Override
        public Fragment getItem(int position) {

            switch (position){
                case 0:


                    Coordonne_client coordonneClient = new Coordonne_client();

                    Bundle bundle = new Bundle();
                    bundle.putString("nomCli", nomClient);
                    bundle.putString("adresseCli", adresseClient);
                    bundle.putString("codePostalClient", codePostalClient);
                    bundle.putString("villeClient", villeClient);
                    bundle.putString("telClient", telClient);
                    coordonneClient.setArguments(bundle);

                    return coordonneClient;

                case 1:
                    Contacts_client contacts_client = new Contacts_client();
                    Bundle bundle2 = new Bundle();
                    bundle2.putString("idClient",idClient);
                    contacts_client.setArguments(bundle2);

                    return contacts_client;



                default:

                    return null;


            }


        }



        @Override
        public int getCount(){

            return 2;

        }

        @Nullable
        @Override
        public CharSequence getPageTitle(int position) {

            return  libelle[position];
        }
    }

This is the Fragment where I want to put a Recycler View :

public class Contacts_client extends Fragment implements Response.ErrorListener, Response.Listener<String> {

    private TextView textView;
    private String idClient;

    RequestQueue queue;
    String url;
    StringRequest stringRequest;

    private RecyclerView recyclerView;
    private RecyclerView.Adapter mAdapter;
    private RecyclerView.LayoutManager layoutManager;
    MyAdapterContactsClient myAdapterContactsClient =new MyAdapterContactsClient();



    public Contacts_client() {

        // 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_contacts_client, container, false);
        idClient = getArguments().get("idClient").toString();

        queue = Volley.newRequestQueue(getActivity().getApplicationContext());
        url = "http://myip/search/contacts/"+idClient;
        stringRequest = new StringRequest(GET, url, Contacts_client.this, Contacts_client.this);
        queue.add(stringRequest);











        return view;
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {

        RecyclerView recyclerView = (RecyclerView)getView().findViewById(R.id.recyclerview_contact_cli);

        recyclerView.setHasFixedSize(true);
        layoutManager= new LinearLayoutManager(getActivity().getApplicationContext());
        recyclerView.setAdapter(myAdapterContactsClient);

    }

    @Override
    public void onErrorResponse(VolleyError error) {

    }

    @Override
    public void onResponse(String response) {
        RecyclerView recyclerView = (RecyclerView)getView().findViewById(R.id.recyclerview_contact_cli);
        Gson gsonContactClient = new Gson();
        ResponseJson responseJson = new ResponseJson();
        responseJson = (ResponseJson) gsonContactClient.fromJson(response, ResponseJson.class);
        List<Object> listContactsClient = responseJson.getResponse();
        try {
            JSONArray contacts = new JSONArray(listContactsClient.toArray());
            ArrayList<String> nomsCli = new ArrayList<String>();
            ArrayList<String> prenomsCli = new ArrayList<String>();
            ArrayList<String> telsCli = new ArrayList<String>();


            for(int i=0; i<contacts.length(); i++){
                JSONObject unContact = contacts.getJSONObject(i);
                nomsCli.add(unContact.get("NOM").toString());
                prenomsCli.add(unContact.get("PRENOM").toString());
                telsCli.add(unContact.get("TEL").toString());
            }

            myAdapterContactsClient.getList(nomsCli, prenomsCli, telsCli);
            recyclerView.setAdapter(myAdapterContactsClient);





        } catch (JSONException e) {
            e.printStackTrace();
        }

    }
}

The .xml of this fragment :

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Fragments_info_client.Contacts_client">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerview_contact_cli"
        android:layout_width="409dp"
        android:layout_height="729dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

At least, the Adapter :

public class MyAdapterContactsClient extends RecyclerView.Adapter<MyAdapterContactsClient.MyViewHolder> {

    private List<String> nomContacts = new ArrayList<>();
    private List<String> prenomContacts = new ArrayList<>();
    private List<String> telContacts = new ArrayList<>();


    public void getList(ArrayList<String> nomContact, ArrayList<String> prenomContact, ArrayList<String> telContact){

        nomContacts.clear();
        prenomContacts.clear();
        telContacts.clear();

        for(int i =1; i<nomContact.size();i++){
                nomContacts.add(nomContact.get(i));
                prenomContacts.add(prenomContact.get(i));
                telContacts.add(telContact.get(i));
        }
        this.notifyDataSetChanged();
    }

    public String getNomContact(int position){
        return nomContacts.get(position);
    }

    public String getPrenomContact(int position){
        return prenomContacts.get(position);
    }

    public String getTelContact(int position){
        return telContacts.get(position);
    }





    @NonNull
    @Override
    public MyAdapterContactsClient.MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        View view = inflater.inflate(R.layout.list_cell_contacts_client, parent, false);
        return new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyAdapterContactsClient.MyViewHolder holder, int position) {

        String nom = nomContacts.get(position);
        String prenom = prenomContacts.get(position);
        String tel = telContacts.get(position);

        holder.display(nom, prenom, tel);


    }

    @Override
    public int getItemCount() {
        return nomContacts.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder{

        private  TextView nomCli;
        private  TextView prenomCli;
        private  TextView telCli;


        public MyViewHolder(@NonNull View itemView) {
            super(itemView);

            nomCli=(TextView)itemView.findViewById(R.id.tv_contacts_nomcli);
            prenomCli=itemView.findViewById(R.id.tv_contacts_prenomcli);
            telCli=itemView.findViewById(R.id.tv_contacts_telcli);



        }

        public void display(String nom, String prenom, String tel) {
            nomCli.setText(nom);
            prenomCli.setText(prenom);
            telCli.setText(tel);

        }
    }
}

I know there is too much code but I really don't know where to look. Let's find together ;) Thank's

---

Update

The breakpoint show me that we never handle the adapter of the recyclerview, only the getList() method and the script is executed when I arrive in the activity, not in the tabs.

Answer 1

You are forget to set layout manager to RecyclerView

 recyclerView.setHasFixedSize(true);
 layoutManager= new LinearLayoutManager(getActivity().getApplicationContext());
 recyclerView.setLayoutManager(layoutManager);
 recyclerView.setAdapter(myAdapterContactsClient);