import javax.swing.*;
public class demo_7
{
	public static void main(String[] args)
	{
		demo_7_1 test=new demo_7_1();
	}
}

class demo_7_1 extends JFrame
{
	public demo_7_1()
	{
		this.setVisible(true);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setBounds(0,0,400,300);
	}
}

像这个代码怎么才能把GridBaglayout写进去啊