learning java AWT Pannel

import java.awt.*;

public class PanelTest {
    public static void main(String[] args) {
        var f = new Frame("测试窗口");
        var p  = new Panel();

        p.add(new TextField(10));
        p.add(new Button("click"));

        f.add(p);

        f.setBounds(30,30,300,500);

        f.setVisible(true);


    }}

result: Pannel can not exist alone, it must be placed in other containers.