import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class PrimaryFrame extends JFrame {
    private SecondFrame secondFrame;//假设SecondFrame一直跟在PrimaryFrame的下边

    public PrimaryFrame() {
    init();
    }

    private void init() {
    setSize(340, 170);
    setTitle("PrimaryFrame");
    setDefaultCloseOperation(3);
    secondFrame = new SecondFrame(this);    
    setVisible(true);    
    addComponentListener(new ComponentAdapter(){
        public void componentMoved(ComponentEvent e){
            secondFrame.setLocation(getX(),getY()+getHeight());//假设SecondFrame一直跟在PrimaryFrame的下边
        }
        public void componentResized(ComponentEvent e) {
        secondFrame.setSize(getWidth(),secondFrame.getHeight());        
        }
    });    

    }

    public static void main(String[] args) {    
    new PrimaryFrame();
    }

}

class SecondFrame extends JFrame {//假设它一直跟在PrimaryFrame的下边
    PrimaryFrame primaryFrame ;
    public SecondFrame(PrimaryFrame primaryFrame){
    this.primaryFrame = primaryFrame;
    init();
    
    }
    private void init(){
    setTitle("SecondFrame");
    setSize(340, 170);
    setLocation(0, 170);
    setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
    setVisible(true);
    addComponentListener(new ComponentAdapter(){
        public void componentResized(ComponentEvent e) {
        primaryFrame.setSize(getWidth(),primaryFrame.getHeight());
        
        }
        @Override public void componentMoved(ComponentEvent e){
            primaryFrame.setLocation(getX(),getY()-primaryFrame.getHeight());//假设SecondFrame一直跟在PrimaryFrame的下边
        }
    });
    }
}