Restoring last opened pdf page after back key press

Question

After back key pressed, I have implemented this code to restore my last opened page in PDF document. Unfortunately, it still load the first page.

    pdfView1 = findViewById(R.id.pdfViewer1);
    pdfView1.fromAsset("cpgTest1.pdf")
            .scrollHandle(new DefaultScrollHandle(this))
            .defaultPage(currentPage)
            .onPageChange(this)
            .load();
}

@Override
public void onPageChanged(int page, int pageCount)
{
    currentPage = page;
}

@Override
public void loadComplete(int nbPages)
{
    if (currentPage >= 0)
    {
        pdfView1.jumpTo(currentPage);
    }}


@Override
public void onSaveInstanceState(Bundle outState)
{
    super.onSaveInstanceState(outState);
    outState.putInt(KEY_CURRENT_PAGE, currentPage);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
    super.onRestoreInstanceState(savedInstanceState);
    currentPage = savedInstanceState.getInt(KEY_CURRENT_PAGE);
}

}

Any thought?