i'm trying to add an element to my recyclerview by the click of a button but each time it end up with a null pointer exeption, can you help me ?
Liste_produits.java :
package com.example.gestiondestocktubconcept.vue;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.FileProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Adapter;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.example.gestiondestocktubconcept.R;
import com.example.gestiondestocktubconcept.modele.Profil;
import org.w3c.dom.Text;
import java.io.File;
import java.io.FileOutputStream;
import java.text.BreakIterator;
import java.util.ArrayList;
import java.util.List;
public class liste_produits extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_liste_produits);
// set up the RecyclerView
RecyclerView recyclerView = findViewById(R.id.rv_produits);
List<Profil> listeProduit = new ArrayList<>();
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(linearLayoutManager);
// initialisation de l'adapter
MyRecyclerViewAdapter adapter = new MyRecyclerViewAdapter(getListeProduit());
recyclerView.setAdapter(adapter);
//this.getListeProduit().add(new Profil("voiture","RF745963-65","twingo",3000.,1,"c une joli voiture"));
}
//addItem(listeProduit,"voiture","RF745963-65","twingo",3000.,1,"c une joli voiture");
List<Profil> listeProduit = new ArrayList<>();
static List<Profil> getListeProduit() {
List<Profil> listeProduit = new ArrayList<>();
//Liste de nos produits
// ajout_produits(listeProduit,txt_categorie,txt_reference,txt_nom,Double.parseDouble(txt_prix),Integer.parseInt(txt_quantite),txt_description);
listeProduit.add(new Profil("Voiture","A1232","Lamborghini Uracan",230000.00,5,"ceci est une description"));
return listeProduit;
}
public static void ajout_produits(List<Profil> listeProduit, String categorie, String reference, String nom, Double prix, int quantite, String descritpion) {
listeProduit.add(new Profil(categorie, reference, nom, prix, quantite, descritpion));
//adapter.notifyItemInserted(adapter.getItemCount()-1);
}
/* ++propriétées++ */
private ListView listView;
MyRecyclerViewAdapter adapter;
Integer nbr_click = 0;
/* --propriétées-- */
public void onClickData(View view) {
EditText txt_input_categorie = (EditText) findViewById(R.id.txt_input_categorie);
EditText txt_input_reference = (EditText) findViewById(R.id.txt_input_reference);
EditText txt_input_nom = (EditText) findViewById(R.id.txt_input_nom);
EditText txt_input_prix = (EditText) findViewById(R.id.txt_input_prix);
EditText txt_input_quantite = (EditText) findViewById(R.id.txt_input_quantite);
EditText txt_input_description = (EditText) findViewById(R.id.txt_input_description);
Button btn_ajouter = (Button) findViewById(R.id.btn_ajouter);
if (txt_input_categorie != null && txt_input_reference != null && txt_input_nom != null && txt_input_prix != null && txt_input_quantite != null && txt_input_description != null) {
String value_description = txt_input_description.getText().toString();
Integer value_quantite = (Integer.valueOf(txt_input_quantite.getText().toString()));
Double value_prix = Double.parseDouble(txt_input_prix.getText().toString());
String value_nom = txt_input_nom.getText().toString();
String value_reference = txt_input_reference.getText().toString();
String value_categorie = txt_input_categorie.getText().toString();
Toast.makeText(getApplicationContext(), "ALED CA MARCHE PAS", Toast.LENGTH_LONG).show();
listeProduit.add(new Profil("voiture", "RF745963-65", "twingo", 3000., 1, "c une joli voiture"));
//listeProduit.add(new Profil(value_categorie, value_reference, value_nom, value_prix, value_quantite, value_description));
adapter.notifyItemInserted(1);
} else {
Toast.makeText(getApplicationContext(), "Veuillez entrer des données", Toast.LENGTH_LONG).show();
}
}
public void export (View view){
/* ++Creation des données++ */
StringBuilder data = new StringBuilder();
data.append("Catégorie,Référence,Nom,Prix,Quantités,Description");
for (int i = 0; i < 6; i++) {
data.append("\n" + "test");
}
/* --Creation des données-- */
try {
/* ++Sauvegarde des données dans l'appareil++ */
FileOutputStream out = openFileOutput("data.csv", Context.MODE_PRIVATE);
out.write((data.toString()).getBytes());
out.close();
/* --Sauvegarde des données dans l'appareil-- */
/* ++Export des données++ */
Context context = getApplicationContext();
File filelocation = new File(getFilesDir(), "data.csv");
Uri path = FileProvider.getUriForFile(context, "com.example.gestiondestocktubconcept.FileProvider", filelocation);
Intent fileIntent = new Intent(Intent.ACTION_SEND);
fileIntent.setType("text/csv");
fileIntent.putExtra(Intent.EXTRA_SUBJECT, "Data");
fileIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
fileIntent.putExtra(Intent.EXTRA_STREAM, path);
startActivity(Intent.createChooser(fileIntent, "Send mail"));
/* --Export des données-- */
} catch (Exception e) {
e.printStackTrace();
}
}
}
MyRecyclerViewAdapter.java :
package com.example.gestiondestocktubconcept.vue;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.example.gestiondestocktubconcept.R;
import com.example.gestiondestocktubconcept.modele.Profil;
import java.util.List;
public class MyRecyclerViewAdapter extends RecyclerView.Adapter {
private AdapterView.OnItemClickListener onItemClickListener;
List<Profil> liste_produit;
//Constructeur de la liste des produits
public MyRecyclerViewAdapter(List<Profil> liste_produit) {
this.liste_produit = liste_produit;
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_row,parent,false);
return new RowViewHolder(itemView);
}
// Lie les élements avec la vue
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
RowViewHolder rowViewHolder = (RowViewHolder) holder;
int rowPos = rowViewHolder.getBindingAdapterPosition();
;
if (rowPos == 0) {
//Cellules de l'entête
// permet de mettre un background a la cellule : rowViewHolder.txt_categorie.setBackgroundResource();
rowViewHolder.txt_categorie.setText("Catégorie");
rowViewHolder.txt_reference.setText("Reference");
rowViewHolder.txt_nom.setText("Nom");
rowViewHolder.txt_prix.setText("Prix");
rowViewHolder.txt_quantite.setText("Quantité");
rowViewHolder.txt_description.setText("Description");
} else{
Profil profil = liste_produit.get(rowPos-1);
//Contenues des cellules
rowViewHolder.txt_categorie.setText(profil.getCategorie()+"");
rowViewHolder.txt_reference.setText(profil.getReference()+"");
rowViewHolder.txt_nom .setText(profil.getNom()+"");
rowViewHolder.txt_prix.setText(profil.getPrixUnite()+"");
rowViewHolder.txt_quantite.setText(profil.getQuantite()+"");
rowViewHolder.txt_description.setText(profil.getDescription()+"");
}
}
@Override
public int getItemCount() {
return liste_produit.size()+1;
}
public class RowViewHolder extends RecyclerView.ViewHolder {
protected TextView txt_categorie;
protected TextView txt_reference;
protected TextView txt_nom;
protected TextView txt_prix;
protected TextView txt_quantite;
protected TextView txt_description;
public RowViewHolder(View itemView) {
super(itemView);
txt_categorie = itemView.findViewById(R.id.tv_categorie_produit);
txt_reference = itemView.findViewById(R.id.tv_reference_produit);
txt_nom = itemView.findViewById(R.id.tv_nom_produit);
txt_prix = itemView.findViewById(R.id.tv_prix_produit);
txt_quantite = itemView.findViewById(R.id.tv_quantite_produit);
txt_description = itemView.findViewById(R.id.tv_description_produit);
}
}
String getItem(int id) {
return String.valueOf(liste_produit.get(id));
}
}
activity_liste_produits.xml :
<?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:id="@+id/constraint_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".vue.liste_produits">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:layout_weight="1"
android:gravity="center|center_horizontal|center_vertical"
android:orientation="horizontal">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/txt_categorie"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:gravity="center|center_horizontal|center_vertical"
android:text="Catégorie : " />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/txt_reference"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:gravity="center|center_horizontal|center_vertical"
android:text="Réference : " />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/txt_nom"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:gravity="center|center_horizontal|center_vertical"
android:text="Nom" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/txt_prix"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:gravity="center|center_horizontal|center_vertical"
android:text="Prix : " />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/txt_quantite"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:gravity="center|center_horizontal|center_vertical"
android:text="Quantités : " />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/txt_description"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center|center_horizontal|center_vertical"
android:gravity="center|center_horizontal|center_vertical"
android:text="Description : " />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical" >
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="onClickData"
android:text="Ajouter Ligne" />
</LinearLayout>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical"
>
<EditText
android:id="@+id/txt_input_categorie"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center|center_vertical"
android:inputType="text"
android:text="test" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<EditText
android:id="@+id/txt_input_reference"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center|center_vertical"
android:inputType="text"
android:text="test" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<EditText
android:id="@+id/txt_input_nom"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center|center_vertical"
android:inputType="text"
android:text="test" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<EditText
android:id="@+id/txt_input_prix"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center|center_vertical"
android:inputType="text"
android:text="12.12" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<EditText
android:id="@+id/txt_input_quantite"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center|center_vertical"
android:inputType="text"
android:text="2" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<EditText
android:id="@+id/txt_input_description"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:gravity="center|center_vertical"
android:inputType="text"
android:text="test" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<Button
android:id="@+id/btn_ajouter"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="export"
android:text="Exporter" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/rv_produits"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<TextView
android:id="@+id/txt_recy_categorie"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Test"
/>
<TextView
android:id="@+id/txt_recy_reference"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Test"
/>
<TextView
android:id="@+id/txt_recy_nom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Test"
/>
<TextView
android:id="@+id/txt_recy_prix"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Test"
/>
<TextView
android:id="@+id/txt_recy_quantite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Test"
/>
<TextView
android:id="@+id/txt_recy_description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Test"
/>
</LinearLayout>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
and his row, recyclerview_row.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
android:orientation="horizontal"
android:padding="10dp">
<TextView
android:id="@+id/tv_categorie_produit"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:autoSizeTextType="uniform"
android:visibility="visible"
app:autoSizeMinTextSize="6sp"
app:autoSizeTextType="uniform" />
<TextView
android:id="@+id/tv_reference_produit"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:autoSizeTextType="uniform"
android:visibility="visible"
app:autoSizeMinTextSize="6sp"
app:autoSizeTextType="uniform" />
<TextView
android:id="@+id/tv_nom_produit"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:autoSizeTextType="uniform"
android:visibility="visible"
app:autoSizeMinTextSize="6sp"
app:autoSizeTextType="uniform" />
<TextView
android:id="@+id/tv_prix_produit"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:autoSizeTextType="uniform"
android:visibility="visible"
app:autoSizeMinTextSize="6sp"
app:autoSizeTextType="uniform" />
<TextView
android:id="@+id/tv_quantite_produit"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:autoSizeTextType="uniform"
android:visibility="visible"
app:autoSizeMinTextSize="6sp"
app:autoSizeTextType="uniform" />
<TextView
android:id="@+id/tv_description_produit"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:autoSizeTextType="uniform"
android:ellipsize="end"
android:maxLength="11"
android:maxLines="1"
android:scrollHorizontally="true"
android:visibility="visible"
app:autoSizeMinTextSize="6sp"
app:autoSizeTextType="uniform" />
</LinearLayout>
here's the logcat error :
java.lang.IllegalStateException: Could not execute method for android:onClick
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:414)
at android.view.View.performClick(View.java:7448)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
at android.view.View.performClickInternal(View.java:7425)
at android.view.View.access$3600(View.java:810)
at android.view.View$PerformClick.run(View.java:28305)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
at android.view.View.performClick(View.java:7448)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
at android.view.View.performClickInternal(View.java:7425)
at android.view.View.access$3600(View.java:810)
at android.view.View$PerformClick.run(View.java:28305)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.example.gestiondestocktubconcept.vue.MyRecyclerViewAdapter.notifyItemInserted(int)' on a null object reference
at com.example.gestiondestocktubconcept.vue.liste_produits.onClickData(liste_produits.java:111)
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
at android.view.View.performClick(View.java:7448)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
at android.view.View.performClickInternal(View.java:7425)
at android.view.View.access$3600(View.java:810)
at android.view.View$PerformClick.run(View.java:28305)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
It's one of my first program so please be indulgent.