Arkadaşlar merhaba sorunum şu şekilde db browser da hazır bir veritabanı android studioda okumuyor hata almıyorum ama değerler yokmuş gibi(yeni öğrenmeye çalışıyorum bu arada)
public class MainActivity extends AppCompatActivity {
VeriTabaniYardimcisi vt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
vt=new VeriTabaniYardimcisi(getApplicationContext());
DatabaseCopyHelper copyHelper = new DatabaseCopyHelper(this);
try {
copyHelper.createDataBase();
} catch (IOException e) {
e.printStackTrace();
}
copyHelper.openDataBase();
ArrayList<İsimler> i̇simlerArrayList=new İsimlerDao().tumKelimeler(vt);
Log.e("mesaj", String.valueOf(i̇simlerArrayList.size()));
}
}
public class VeriTabaniYardimcisi extends SQLiteOpenHelper {
public VeriTabaniYardimcisi(@Nullable Context context) {
super(context,“deneme”,null,1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE IF NOT EXISTS \"İsimler\"(\n" +
"\t\"isim_id\"\tINTEGER,\n" +
"\t\"ad\"\tTEXT,\n" +
"\t\"soyad\"\tTEXT,\n" +
"\tPRIMARY KEY(\"isim_id\"AUTOINCREMENT)\n" +
")");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXİSTS İsimler");
onCreate(db);
}
}
public class İsimlerDao {
public ArrayList<İsimler> tumKelimeler(VeriTabaniYardimcisi vt){
ArrayList<İsimler> kelimelerArrayList=new ArrayList<>();
SQLiteDatabase dbx=vt.getWritableDatabase();
Cursor c=dbx.rawQuery(“SELECT * FROM İsimler”,null);
while(c.moveToNext()){
İsimler kelimeler=new İsimler(c.getInt(c.getColumnIndex("isim_id")),c.getString(c.getColumnIndex("ad")),c.getString(c.getColumnIndex("soyad")));
kelimelerArrayList.add(kelimeler);
}
return kelimelerArrayList;
}
}
public class İsimler {
private int isim_id;
private String ad;
private String soyad;
public İsimler(){
}
public İsimler(int kelime_id, String iad, String soyad) {
this.isim_id = kelime_id;
this.ad = ad;
this.soyad = soyad;
}
public int getIsim_id() {
return isim_id;
}
public void setIsim_id(int isim_id) {
this.isim_id = isim_id;
}
public String getAd() {
return ad;
}
public void setAd(String ad) {
this.ad = ad;
}
public String getSoyad() {
return soyad;
}
public void setSoyad(String soyad) {
this.soyad = soyad;
}
}
public class DatabaseCopyHelper extends SQLiteOpenHelper {
//The Android's default system path of your application database.
String DB_PATH =null;
private static String DB_NAME = "deneme.sqlite";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public DatabaseCopyHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
DB_PATH="/data/data/"+context.getPackageName()+"/"+"databases/";
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
@Override
public void onOpen(SQLiteDatabase db) {
super.onOpen(db);
db.disableWriteAheadLogging();
}
//return cursor
}
arraylist in size değerini 0 olarak alıyorum,assets dosyasında deneme.sqlite bulunuyor,nedeni ne olabilir?