如何将数据库文件从资产文件夹复制到/ data / data / <package-name> /数据库文件夹

Question

I have put a database file in to assets folder and want to copy it to /data/data//database folder . For this purpose , I have written the following code :

public void copy()
{
    try
    {
        String dest_path = "/data/data/"+getPackageName()+"/database/sultandatabase";
        File f = new File(dest_path);
        if( !f.exists() )
        {
            copy_database(getBaseContext().getAssets().open(db_name),new FileOutputStream(dest_path));
        }
    }
    catch(Exception e)
    {
        Toast.makeText(this,"Sorry the file can not be opended", Toast.LENGTH_LONG).show();

    }
}

public void copy_database(InputStream io ,OutputStream ou) throws Exception
{
    byte[] buffer = new byte[1024] ;
    int lenght;

    while( ( lenght = io.read(buffer)) > 0 )
        ou.write(buffer);
    io.close();
    ou.close();

}

When I call copy() the database file is not copied . What is the possible reason ?? How can I fix this ?? Instead a toast is shown up . That means my program gets Exception ?? But why ??

Answer 1

i have this code for copy:

private void copyDataBase()
{
    try
    {
    InputStream myInput = myContext.getAssets().open(DATABASE_NAME);
    String outFileName = DATABASE_PATH + DATABASE_NAME;
    OutputStream myOutput = new FileOutputStream(outFileName);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer))>0)
    {
        myOutput.write(buffer, 0, length);
    }

    myOutput.flush();
    myOutput.close();
    myInput.close();
    }
    catch(Exception ex)
    {
        ex.printStackTrace();
    }
}