利用面向对象思想来做购物车

/**
*   <p>Title:   购物车</p>
*   <p>Description:   实现对商城购物车的操作</p>
*   <p>Copyright:   Copyright   (c)   2006</p>
*   <p>Company:   公司</p>
*   @author  blurxx
*   @version   1.1
*/

package order;


import java.util.Hashtable;
import org.apache.log4j.Logger;
import java.util.Enumeration;
import order.vo.ProductCart;

public class orderBean {

    Logger log = Logger.getLogger(OrderBean.class);
    public Hashtable itemHashtable = new Hashtable();

    public void setItemHashtable(Hashtable ht) {
        itemHashtable = ht;
    }

    public Hashtable getItemHashtable() {
        return itemHashtable;
    }

    /**
     *
     * @添加商品
     */
    public void addItem(ProductCart pt) {
        int id = pt.getId();
        //String item[]={Integer.toString(id),name,Double.toString(price),Integer.toString(entries)};
        //如果购物车中有此ID号
        if (itemHashtable.containsKey(Integer.toString(id))) {
            //取得原有此种类型商品集合
            ProductCart workItem = (ProductCart) itemHashtable.get(Integer.
                    toString(
                            id));
            //取得原来条目
            int oldentries = workItem.getEntries();
            //加上新加条目
            int workEntries = pt.getEntries() + oldentries;
            //总和放入pt对象中更新
            pt.setEntries(workEntries);
            //把此类型商品再加入购物车
            itemHashtable.put(Integer.toString(id), pt);
        } else {
            itemHashtable.put(Integer.toString(id), pt);
        }

    }

    public void updateItem(ProductCart pt) {
        int id = pt.getId();
        //String item[]={Integer.toString(id),name,Double.toString(price),Integer.toString(entries)};
        if (itemHashtable.containsKey(Integer.toString(id))) {
            //取得条目
            int workEntries = pt.getEntries();
            pt.setEntries(workEntries);
            itemHashtable.put(Integer.toString(id), pt);
        } else {
            itemHashtable.put(Integer.toString(id), pt);
        }
    }

    /**
     * 删除某一类商品
     * @return null
     */
    public void ItemdelByKey(int id) {
        //int id=pt.getId();
        //String item[]={Integer.toString(id),name,Double.toString(price),Integer.toString(entries)};
        if (itemHashtable.containsKey(Integer.toString(id))) {
            itemHashtable.remove(Integer.toString(id));
        } else {
            return;
        }
    }


    /**
     * 价格总和
     * @return double
     */
    public double getCost() {
        Enumeration enuma = itemHashtable.elements();
        ProductCart workItem;
        double totalCost = 0.00;
        while (enuma.hasMoreElements()) {
            workItem = (ProductCart) enuma.nextElement();
            //总和＝个数(条目)*单价
            totalCost = totalCost +
                        workItem.getEntries() *
                        workItem.getPrice();
        }
        return totalCost;
    }

    /**
     *   购物车商品类数 //总共多少件商品
     *   @return   int
     */
    public int getNumofItem() {
        Enumeration enuma = itemHashtable.elements();
        ProductCart workItem;
        int num = 0;
        while (enuma.hasMoreElements()) {
            workItem = (ProductCart) enuma.nextElement();
            num = num + workItem.getEntries();
        }
        return num;
    }


    /**
     *   清空购物车记录
     */
    public void ClearItem() {
        itemHashtable.clear();
    }


    public static void main(String[] args) {
        orderBean orderbean = new orderBean();
    }
}

package order.vo;

/**
* 用于作为购物车中的值传递
* <p>Title: </p>
*
* <p>Description: </p>
*
* <p>Copyright: Copyright (c) 2006</p>
*
* <p>Company: </p>
*
* @author not attributable
* @version 1.0
*/
import java.io.Serializable;

public class ProductCart implements Serializable {
    private int id;
    private String name;
    private double price;
    private int entries;
    public static void main(String[] args) {
        ProductCart productcart = new ProductCart();
    }

    public void setId(int id) {
        this.id = id;
    }

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

    public void setPrice(double price) {
        this.price = price;
    }

    public void setEntries(int entries) {
        this.entries = entries;
    }

    public int getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public double getPrice() {
        return price;
    }

    public int getEntries() {
        return entries;
    }
}