组合模式

public interface WindowComponentPrinter {
    void print();
}
public class WindowComponentNonLeafDemo implements WindowComponentPrinter {
    private List<WindowComponentPrinter> components;
    public void addComponent(WindowComponentPrinter windowComponentPrinter) {
        if (Objects.isNull(components)) {
            components = new ArrayList<>();
        }
        components.add(windowComponentPrinter);
    }
    @Override
    public void print() {
        components.forEach(WindowComponentPrinter::print);
    }
    public static void main(String[] args) {
        WindowComponentNonLeafDemo frame = new WindowComponentNonLeafDemo();
        frame.addComponent(() -> System.out.println("print Frame（FRAME1）"));
        frame.addComponent(() -> System.out.println("print Lable（用户名）"));
        frame.addComponent(() -> System.out.println("print TextBox（文本框）"));
        frame.addComponent(() -> System.out.println("print Lable（密码）"));
        frame.addComponent(() -> System.out.println("print PasswordBox（密码框）"));
        frame.addComponent(() -> System.out.println("print CheckBox（复选框）"));
        frame.addComponent(() -> System.out.println("print TextBox（记住用户名）"));
        frame.addComponent(() -> System.out.println("print LinkLable（忘记密码）"));
        WindowComponentNonLeafDemo mainWindow = new WindowComponentNonLeafDemo();
        mainWindow.addComponent(() -> System.out.println("print WinForm（WINDOWS窗口）"));
        mainWindow.addComponent(() -> System.out.println("print Picture（LOGO图片）"));
        mainWindow.addComponent(() -> System.out.println("print Button（登陆）"));
        mainWindow.addComponent(() -> System.out.println("print Button（注册）"));
        mainWindow.addComponent(frame::print);
        mainWindow.print();
    }
}