shoppingcart.java

DAO模式写的购物车程序

package org.shoppingCart;
import org.basket.Product;
import org.interfaceclass.productDao;
import org.item.Item;
import org.time.time;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Iterator;

public class ShoppingCart implements productDao {
    private static HashMap map=new HashMap();
	
	public void add(Product aa,int num){
	if(map.containsKey(aa.getId()))	
		{
	Item item=(Item)map.get(aa.getId());//通过K找到V
	int num1=item.getNum();
	num1+=num;
	map.put(aa.getId(),new Item(aa,num1));		
	}
	else{
	map.put(aa.getId(),new Item(aa,num));
	}
	
}
 public void modify(Product aa,int num){
    if(map.containsKey(aa.getId()))	{
	Item item=(Item)map.get(aa.getId());//通过K找到V
	int num2=item.getNum();
	num2-=num;
	if(num2<=0)
		{map.remove(aa.getId());}
	else
	map.put(aa.getId(),new Item(aa,num2));		
	}
 }	
  
 public void print(){
 	   time ti=new time();
	   System.out.println("乐购超市购物单     "+ti.getResult());
	   System.out.println();
	   System.out.println("编码   数量  名称  单价    总价(元)");
       System.out.println("---------------------------------");
	   double prices=0.0;
	  Set set_kv =map.entrySet();
	  Iterator item=set_kv.iterator();
	  while(item.hasNext())
	  {for (int i = 0; i < map.size(); i++) 
       { Map.Entry me = (Map.Entry)item.next(); 
	     String key =(String) me.getKey();
         Item ite=(Item) me.getValue();
         Product pro=ite.getPro();
         float price1=pro.getPrice(); 
		 String id1=pro.getId();
	     String name1=pro.getName();
		 double price2=price1*ite.getNum();
         prices+=price2;
	     System.out.println(id1+"    "+ite.getNum()+"    "+name1+"   "+price1+"    "+price2);
	   
	   }
	   System.out.println("----------------------------------");
	   System.out.println("                     总价："+prices);
	   System.out.println("          欢迎惠顾!               ");
	   System.out.println();
	  }
  }
}