add DB files

app/src/main/java/com/example/tpleboncoin/db/DBHelper.java

+package com.example.tpleboncoin.db;
+
+// Package + Import
+
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+
+import com.example.tpleboncoin.models.Annonce;
+
+public class DBHelper extends SQLiteOpenHelper {
+
+    // Table Name
+    public static final String TABLE_NAME = "annonces";
+
+    // Table columns
+    public static final String _ID = "id";
+    public static final String TITLE = "titre";
+    public static final String ADDRESS = "adresse";
+    public static final String IMAGE = "image";
+    public static final String PRICE = "prix";
+
+    // Database Information
+    static final String DB_NAME = "LEBONCOIN.DB";
+
+    // database version
+    static final int DB_VERSION = 1;
+
+    // Creating table query
+    private static final String CREATE_TABLE = "create table " + TABLE_NAME + "(" + _ID
+            + " INTEGER PRIMARY KEY AUTOINCREMENT, " + TITLE + " TEXT NOT NULL, " + ADDRESS + " TEXT, " + IMAGE + " TEXT, " + PRICE + " DOUBLE);";
+
+    public DBHelper(Context context) {
+        super(context,
+                DB_NAME,
+                null,
+                DB_VERSION);
+    }
+
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        db.execSQL(CREATE_TABLE);
+    }
+
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
+        onCreate(db);
+    }
+
+    // Util if you want to add a clicklistener on specific ad in listview.
+    public Annonce getById(long id) {
+        SQLiteDatabase db=this.getWritableDatabase();
+        String query="SELECT * FROM "+TABLE_NAME+" where "+ _ID + "=?";
+        Cursor data = db.rawQuery(query,new String[] {String.valueOf(id)});
+        if (data != null) {
+            data.moveToFirst();
+        }
+        else{
+            return null;
+        }
+
+        String title = data.getString(data.getColumnIndexOrThrow(TITLE));
+        String address = data.getString(data.getColumnIndexOrThrow(ADDRESS));
+        String image = data.getString(data.getColumnIndexOrThrow(IMAGE));
+        double price = data.getDouble(data.getColumnIndexOrThrow(PRICE));
+
+        data.close();
+
+        return new Annonce(title, address, image, price);
+    }
+}

app/src/main/java/com/example/tpleboncoin/db/DBManager.java

+package com.example.tpleboncoin.db;
+
+// Package + Import
+
+import static java.lang.Math.abs;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+
+import com.example.tpleboncoin.models.Annonce;
+
+import java.util.ArrayList;
+
+public class DBManager {
+
+    public static DBManager DBManager;
+
+    private DBHelper dbHelper;
+    private Context context;
+    private SQLiteDatabase database;
+
+    private DBManager(Context c) {
+        context = c;
+        //init(); // Useful for adding ads for the first time.
+    }
+
+    public static DBManager getDBManager(Context context) {
+        if (DBManager == null){
+            return new DBManager(context);
+        }
+        return DBManager;
+    }
+
+    public DBManager open() throws SQLException {
+        dbHelper = new DBHelper(context);
+        database = dbHelper.getWritableDatabase();
+        return this;
+    }
+
+    public void close() {
+        dbHelper.close();
+    }
+
+    // Add ads manually.
+    public void init(){
+        open();
+        insert(new Annonce("Wood", "Douai", "https://media.istockphoto.com/id/134253640/photo/construction-of-a-wooden-roof-frame-underway.jpg?s=612x612&w=0&k=20&c=e5gUkic9LGQWahIdHozOsEzHKy_HtsmvmtOHmYsejSU=",24.99));
+        insert(new Annonce("Steel", "Lille", "https://as2.ftcdn.net/v2/jpg/03/91/83/87/1000_F_391838708_4HFADW5beay2VVlnoual6Qi5fWeIaD9V.jpg", 18.9));
+        insert(new Annonce("Clay", "Douai", "https://constrofacilitator.com/wp-content/uploads/2020/02/clay-in-construction.jpg", 7.88));
+        insert(new Annonce("Metal", "Lyon", "https://www.meto-constructions.fr/wp-content/uploads/2018/12/IMG_6067.jpg", 12.99));
+        insert(new Annonce("Glass", "Valenciennes", "https://i0.wp.com/www.tipsnepal.com/wp-content/uploads/2020/09/simple-float-glass-1505049573-3306125.jpeg?resize=500%2C317&quality=100&strip=all&ssl=1", 12.0));
+        insert(new Annonce("Wood", "Orchies", "https://yieldpro.com/wp-content/uploads/2020/08/lumber1.jpg", 3));
+    }
+
+    public void insert(Annonce ad) {
+        ContentValues contentValue = new ContentValues();
+        contentValue.put(DBHelper.TITLE, ad.getTitre());
+        contentValue.put(DBHelper.ADDRESS, ad.getAdresse());
+        contentValue.put(DBHelper.IMAGE, ad.getImage());
+        contentValue.put(DBHelper.PRICE, ad.getPrix());
+        database.insert(DBHelper.TABLE_NAME, null, contentValue);
+    }
+
+    public Cursor fetch() {
+        String[] columns = new String[] { DBHelper._ID, DBHelper.TITLE, DBHelper.ADDRESS, DBHelper.IMAGE};
+        Cursor cursor = database.query(DBHelper.TABLE_NAME, columns, null, null, null, null, null);
+        if (cursor != null) {
+            cursor.moveToFirst();
+        }
+        return cursor;
+    }
+
+    public int update(long _id, Annonce ad) {
+        ContentValues contentValues = new ContentValues();
+        contentValues.put(DBHelper.TITLE, ad.getTitre());
+        contentValues.put(DBHelper.ADDRESS, ad.getAdresse());
+        contentValues.put(DBHelper.IMAGE, ad.getImage());
+        contentValues.put(DBHelper.PRICE, ad.getPrix());
+
+        int i = database.update(DBHelper.TABLE_NAME, contentValues, DBHelper._ID + " = " + _id, null);
+
+        return i;
+    }
+
+    public void delete(long _id) {
+        database.delete(DBHelper.TABLE_NAME, DBHelper._ID + "=" + _id, null);
+    }
+
+    public Annonce getById(int id){
+        return dbHelper.getById(id);
+    }
+
+    public ArrayList<Annonce> getAll(){
+        ArrayList<Annonce> annonces = new ArrayList<Annonce>();
+
+        Cursor cursor = this.fetch();
+
+        if (cursor.moveToFirst()) {
+            do {
+                String titre = cursor.getString(abs(cursor.getColumnIndex(DBHelper.TITLE)));
+                String adresse = cursor.getString(abs(cursor.getColumnIndex(DBHelper.ADDRESS)));
+                String image = cursor.getString(abs(cursor.getColumnIndex(DBHelper.IMAGE)));
+                double prix = cursor.getDouble(abs(cursor.getColumnIndex(DBHelper.PRICE)));
+
+                annonces.add(new Annonce(titre, adresse, image, prix));
+            } while (cursor.moveToNext());
+        }
+
+        return annonces;
+    }
+
+}