【课后作业】20200304_门面模式与装饰器模式详解

1、请举例3-5个使用门面模式的应用场景。

A.公司前台  B.银行大堂经理  C.建筑包工头

2.使用装饰器模式实现一个可根据权限动态扩展功能的导航条。

public class NavItem {
    private String name;

    public NavItem(String name){
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

public interface INavBar {
    List<NavItem> getNavItems();
}

public class BaseNavBar implements INavBar {
    @Override
    public List<NavItem> getNavItems() {
        List<NavItem> navItems = new ArrayList<NavItem>();
        navItems.add(new NavItem("问答"));
        navItems.add(new NavItem("文章"));
        navItems.add(new NavItem("精品课"));
        navItems.add(new NavItem("冒泡"));
        navItems.add(new NavItem("商城"));
        return navItems;
    }
}

public abstract class AbstractNavBarDecorator implements INavBar {

    private INavBar iNavBar;

    public AbstractNavBarDecorator(INavBar iNavBar){
        this.iNavBar = iNavBar;
    }

    @Override
    public List<NavItem> getNavItems() {
        return this.iNavBar.getNavItems();
    }
}

public class VipNavBarDecorator extends AbstractNavBarDecorator {
    public VipNavBarDecorator(INavBar iNavBar) {
        super(iNavBar);
    }

    @Override
    public List<NavItem> getNavItems() {
        List<NavItem> items = super.getNavItems();
        items.add(new NavItem("作业"));
        items.add(new NavItem("题库"));
        return items;
    }
}

public class Client {

    public static void main(String[] args) {
        INavBar bar = new BaseNavBar();
        bar = new VipNavBarDecorator(bar);
        System.out.println(bar.getNavItems());
    }
}