Java – databases are not copied from assets

It's hard to say. Just paste my code. I hope someone will see what I'm missing:

Database.Java

package gr.peos;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.sqlException;
import android.database.sqlite.sqliteDatabase;
import android.database.sqlite.sqliteException;
import android.database.sqlite.sqliteOpenHelper;

public class Database extends sqliteOpenHelper{

//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/gr.peos/databases/";

//Name of the Database to be created.
private static String DB_NAME = "BLib";

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 Database(Context context) {

    super(context, DB_NAME, null, 1);
    this.myContext = context;
}   

/**
 * Creates a empty database on the system and rewrites it with your own database.
 * */

public void createDataBase() throws IOException{

    //First we check if the database already exists, Method declared later
    boolean dbExist = checkDataBase(); 

    if(dbExist){
        //do nothing - database already exists
    }else{

        //By calling this method an empty database will be created into the default system path
           //of your application so we are going to be able to overwrite that database with our database.
        this.getReadableDatabase();

        try {
            copyDataBase(); //Method declared later

        } 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 transferring byte stream.
 * */

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();

}




//opening the Database
public void openDataBase() throws sqlException{

    //Open the database
    String myPath = DB_PATH + DB_NAME;
    myDataBase = sqliteDatabase.openDatabase(myPath, null, sqliteDatabase.OPEN_READONLY);

}


/
//Finally overriding a few methods as required

@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) {

}

}

The part that calls it is the oncreate method of my main activity (it's not a problem to try others)

 Database myDbHelper = new Database(null);
    myDbHelper = new Database(this);

    try {
        myDbHelper.createDataBase();

    } catch (IOException ioe) {

        throw new Error("Unable to create database");
        }

try {



}catch(sqlException sqle){

    throw sqle;

  }

Now the strange part. On my device (I don't have root permission, so I can't extract the database after creating the database), my data seems to be 48KB. When running exactly the same code on the simulator, the database will not be copied (I won't choose any exceptions). To be sure, the Android / metadata table seems to be copied, but there are no other tables and data. Do you have any ideas?

resolvent:

I'll give you the complete code. If you succeed, please reply

public class DataBaseHelper extends sqliteOpenHelper{
private Context mycontext;

private String DB_PATH = "/data/data/gr.peos/databases/";
//private String DB_PATH = mycontext.getApplicationContext().getPackageName()+"/databases/";
private static String DB_NAME = "BLib.sqlite";//the extension may be .sqlite or .db
public sqliteDatabase myDataBase;
/*private String DB_PATH = "/data/data/"
                            + mycontext.getApplicationContext().getPackageName()
                            + "/databases/";*/

public DataBaseHelper(Context context) throws IOException  {
    super(context,DB_NAME,null,1);
    this.mycontext=context;
    boolean dbexist = checkdatabase();
    if(dbexist)
    {
        //System.out.println("Database exists");
        opendatabase(); 
    }
    else
    {
        System.out.println("Database doesn't exist");
    createdatabase();
    }

}

public void createdatabase() throws IOException{
    boolean dbexist = checkdatabase();
    if(dbexist)
    {
        //System.out.println(" Database exists.");
    }
    else{
        this.getReadableDatabase();
    try{
            copydatabase();
        }
        catch(IOException e){
            throw new Error("Error copying database");
        }
    }
}
private boolean checkdatabase() {
    //sqliteDatabase checkdb = null;
    boolean checkdb = false;
    try{
        String myPath = DB_PATH + DB_NAME;
        File dbfile = new File(myPath);
        //checkdb = sqliteDatabase.openDatabase(myPath,null,sqliteDatabase.OPEN_READWRITE);
        checkdb = dbfile.exists();
    }
    catch(sqliteException e){
        System.out.println("Database doesn't exist");
    }

    return checkdb;
}
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("/data/data/gr.peos/databases/BLib.sqlite");

    // transfer byte to inputfile to 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_READWRITE);

}



public synchronized void close(){
    if(myDataBase != null){
        myDataBase.close();
    }
    super.close();
}