设计模式学习之——六大设计原则之六：开闭原则

public interface IBook
{
    string getName();
    int getPrise();
    string getAuthor();
}

public class NovelBook implements IBook
{
    private String name;
    private int price;
    private String author;
    public NovelBook(String _name, int _price, String _author)
    {
        this.name = _name;
        this.price = _price;
        this.author = _author;
    }
    public String getName()
    {
        return this.author;
    }
 
    public int getPrise()
    {
        return this.price;
    }
 
    public String getAuthor()
    {
        return this.author;
    }
}

public class BookStore
{
    private final static ArrayList<IBook> bookList= new ArrayList<IBook>();
    //static 静态模块初始化数据，实际项目中由持久层完成
    static{
        bookList.add(new NovelBook("天龙八部",3200,"金庸"));
        bookList.add(new NovelBook("巴黎圣母院",5600,"雨果"));
    }
    public static void main(String[] args){
        NumberFormat formatter = NumberFormat.getCurrencyInstance();
        formatter.setMaxmumFractionDigits(2);
        System.out.printIn("-----------书店卖出去的书记录如下：--------------");
        for(IBook book: bookList){
        System.out.printIn("书名：" + book.getName() + "\t作者：" + book.getAuthor() + "\t价格：" + formatter.format(book.)getPrice()/100.0) + "元");
        }
    }
}

public class OffNovelBook : NovelBook
{
    public OffNovelBook(string _name, int _price, string _author)
    {
        super(_name, _price, _author);
    }
    @Override
    public int getPrice()
    {
        int selfPrice = super.getPrice();
        int offPrice = 0;
        if (selfPrice > 4000){
            offPrice = selfPrice * 90 / 100;
        }
        else {
            offPrice = selfPrice * 80 / 100;
        }
        return offPrice;
    }
}

static{
    bookList.add(new OffNovelBook("天龙八部",3200,"金庸"));
    bookList.add(new OffNovelBook("巴黎圣母院",5600,"雨果"));
}