'm using following code to copy sqlite file from asset folder to database folder. i found this example here  find CommonsWare's answer in this question 
But im getting java.io.FileNotFoundException: /file:/android_asset/pg558.sqlite (No such file or directory)
void copy() throws IOException {
    InputStream in =getApplicationContext().getAssets().open("pg558.sqlite");
    OutputStream out = new FileOutputStream("data/data/com.mireader/databases/MIBOOK");
    // Transfer bytes from in to out
    byte[] buf = new byte[1024];
    int len;
    while ((len = in.read(buf)) > 0) {
        out.write(buf, 0, len);
    }
    in.close();
    out.close();
}