java awt图形化编程

package com.one.container;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class WindowDemo {
    public static void main(String[] args) {
        Frame frame = new Frame("这是测试windo w窗口");
        Panel panel = new Panel(new FlowLayout(FlowLayout.LEFT,100000000,2000000));
        CardLayout cardLayout = new CardLayout();
        panel.setLayout(cardLayout);
        String[] names = {"第一张", "第二张", "第三张", "第四张", "第五张"};
        for (int i = 0; i < 5; i++) {
            panel.add(names[i], new Button(names[i]));
        }
        //panel.add(new TextField(30));
        frame.add(panel);
        Panel panel1 = new Panel();
        Button b1 = new Button("上一张");
        Button b2 = new Button("下一张");
        Button b3 = new Button("第一张");
        Button b4 = new Button("最后一张");
        Button b5 = new Button("第三张");
        panel1.add(b1);
        panel1.add(b2);
        panel1.add(b3);
        panel1.add(b4);
        panel1.add(b5);
        ActionListener listener = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String actionCommand = e.getActionCommand();
                switch (actionCommand) {
                    case "上一张":
                        cardLayout.previous(panel);
                        ;
                        break;
                    case "下一张":
                        cardLayout.next(panel);
                        ;
                        break;
                    case "第一张":
                        cardLayout.first(panel);
                        ;
                        break;
                    case "最后一张":
                        cardLayout.last(panel);
                        ;
                        break;
                    case "第三张":
                        cardLayout.show(panel, "第三张")
                        ;
                        break;


                }
            }
        };
        b1.addActionListener(listener);
        b2.addActionListener(listener);
        b3.addActionListener(listener);
        b4.addActionListener(listener);
        b5.addActionListener(listener);
        frame.add(panel1,BorderLayout.SOUTH);
  frame.pack();
    
        frame.setVisible(true);

    }
}

为啥 我再BoardLayout布局南侧放置的Panel容器前面会有空格，还会因为我的拉动窗口变大啊，不是流式布局吗？