shoppingcart.java

网上书城源代码~~在学习JAVA的时候做的

package com.briup.bean;

import java.util.Collection;
import java.util.Map;
import java.util.TreeMap;

public class ShoppingCart {
	private Map<Long,Orderline> cart = new TreeMap<Long,Orderline>();
	
	//增加Orderline
	public void addLine(Orderline line) {
		Orderline orderline = cart.get(line.getBook().getId());
		if(orderline != null) 
			orderline.setNum(orderline.getNum()+line.getNum());
		else if(line.getNum()>0)
			cart.put(line.getBook().getId(), line);
	}
	
	//删除Orderline
	public void dropLine(Long lineid) {
		cart.remove(lineid);
	}
	
	//获得单个Orderline
	public Orderline getOrderline(Long lineid){
		return cart.get(lineid);
	}
	
	//获得所有Orderline
	public Collection<Orderline> getOrderlines() {
		return cart.values();
	}
	
	//获得购物车总价
	public double getCost() {
		double cost = 0.0;
		Collection<Orderline> c = getOrderlines();
		for(Orderline orderline : c){
			cost += orderline.getBook().getPrice() * orderline.getNum();
		}
		return cost;
	}
	
	//清空购物车ﳵ
	public void removeAll() {
		cart.clear();
	}
	
	//判断购物车是否为空
	public boolean isEmpty(){
		return cart.isEmpty();
	}
}