public interface Component {
    public void rend();
}
public class BaseCompoment {
    private String label;
    public String getLabel() {
        return label;
    }
    public void setLabel(String label) {
        this.label = label;
    }
}
public class Window extends BaseCompoment implements Component {
    public Window(String label) {
        setLabel(label);
    }
    private List<Component> components = new ArrayList<>();
    public void addComponent(List<Component> components) {
        this.components.addAll(components);
    }
    @Override
    public void rend() {
        System.out.println(this.getClass().getName() + " - " + this.getLabel());
        for (int i = 0; i < components.size(); i++) {
            Component component = components.get(i);
            component.rend();
        }
    }
}
public class Button extends BaseCompoment implements Component {
    public Button(String label) {
        setLabel(label);
    }
    @Override
    public void rend() {
        System.out.println(this.getClass().getName() + " - " + this.getLabel());
    }
}
package medo.pattern.oo.composite;
import java.util.ArrayList;
import java.util.List;
import medo.pattern.oo.composite.component.Button;
import medo.pattern.oo.composite.component.Frame;
import medo.pattern.oo.composite.component.Input;
import medo.pattern.oo.composite.component.Label;
import medo.pattern.oo.composite.component.Picture;
import medo.pattern.oo.composite.component.Window;
public class Login {
    public void login() {
        Window window = new Window("WINDOW");
        List<Component> subWindow = new ArrayList<>();
        subWindow.add(new Picture("Logo"));
        window.addComponent(subWindow);
        Frame frame = new Frame("Frame");
        List<Component> asList = new ArrayList<>();
        asList.add(new Input("input"));
        asList.add(new Label("label"));
        asList.add(new Button("login"));
        asList.add(new Button("regist"));
        frame.addComponent(asList);
        List<Component> frameSub = new ArrayList<>();
        frameSub.add(frame);
        window.addComponent(frameSub);
        window.rend();
    }
}