Problem with resizing

I have a problem when I try to resize my program as I am working in a
JPanel inside a JPanel
The problem is, that the inside JPanel does not resize

I have created a little example of how I have created the JPanels and
JFrame as my source code is too large to be showed in here.
The source code is:

class Tab1 extends JFrame {

    public Tab1() {

        // Construct the panel
        JPanel panel1 = new JPanel();
        this.getContentPane().add(panel1);

        // Construct the tabbed panel
        JTabbedPane jTabPane = new JTabbedPane();
        jTabPane.add("Tab #1", new Tab2());
        jTabPane.add("Tab #2", new JPanel());
        panel1.add(jTabPane);

        // Construct the frame
        this.pack();
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setVisible(true);
    }
}

class Tab2 extends JPanel {

    public Tab2() {

        // Construct the Panel
        JPanel panel1 = new JPanel();
        this.add(panel1);

        // Construct the tabbed pane
        JTabbedPane jTabPane = new JTabbedPane();
        jTabPane.add("Tab #1#1", new JPanel());
        this.add(jTabPane);
    }
}