Criar um JFrame com tamanho exato

public MyFrame(int width, int height){
    JFrame temp = new JFrame;
    temp.pack();
    Insets insets = frame.getInsets();
    temp = null;

    this.setSize(new Dimension(insets.left + insets.right + width,
             insets.top + insets.bottom + height));
    this.setResizable(false);
}

public MyFrame(int width, int height) {
    JPanel temp = new JPanel();
    temp.setPreferredSize(new Dimension(width, height));
    this.add(temp);
    pack();
    this.remove(temp);    
    this.setResizable(false);
}