######03.经典实体Bean设计：购物项-购物车；订单项-订单。---记录。便于复习。借鉴设计思想

Bean设计 总思路：（有轻逻辑的Bean）

购物车功能：

①先有购物项CartItem，再有购物车Cart 对其封装。-----和“分页”的PageBean封装类似。都是为了便于页面取值显示数据。

===【当然，这里Cart对CartItem的封装。除了页面取值方便，更重要的是：购物项和购物车 有个各自的轻逻辑(业务需要)：

CartItem：除了表字段映射的属性，还有“小计总价”这个轻逻辑。

Cart：除了表字段映射的属性，还有“总价”、“购物积分”这个轻逻辑。

此外，###【最容易忽视，和表字段属性弄混的业务属性】，就是 封装CartItem的Map<String,CartItem> map属性。

 】

订单功能：（和购物车思想类似）

②先有OrderItem，再有Orders（名也可以叫Order）。

===============Bean代码如下：

购物车功能：

package cn.itcast.domain;import java.io.Serializable;public class CartItem implements Serializable{private Product pro;private int count;private double total;//价格小计public CartItem() {super();}public CartItem(Product pro, int count, double total) {super();this.pro = pro;this.count = count;this.total = total;}public Product getPro() {return pro;}public void setPro(Product pro) {this.pro = pro;}public int getCount() {return count;}public void setCount(int count) {this.count = count;}public double getTotal() {return total = pro.getShop_price()*count;}@Overridepublic String toString() {return "CartItem [pro=" + pro.getPname() + ", count=" + count + ", total=" + getTotal() + "]";}}

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package cn.itcast.domain;import java.io.Serializable;import java.util.Collection;import java.util.LinkedHashMap;import java.util.List;import java.util.Map;/*=====【思想和PageBean一样的，都是要封装。】========【把CartItem封装到Cart而不是 集合。因为整个还要计算所有CartItem的总价，总积分。====正因为存在这些轻逻辑。所以再次封装一个实体。便于操作。面向对象。==###==【一个Cart，CartItem通常不止一个】，所以要存到集合里。===涉及选哪种集合。===哪种集合最终都可以实现。只是实现语法不同。如果选用List，可重复，需要判断重复。Cart实体还要重写equals方法；Set，不可重复。无序。Map，不可重复。无序。?】 * */public class Cart implements Serializable {//private Map<String,CartItem> items;private Map<String,CartItem> items = new LinkedHashMap<String,CartItem>();private int score;//购物积分。private double totalMoney;public Cart() {super();}public Cart(Map<String,CartItem> items, int score, double totalMoney) {super();this.items = items;this.score = score;this.totalMoney = totalMoney;}/*public Map<String,CartItem> getItems() {return items;}//========######====【这个写错，导致页面显示不了。】//======property Pro  is not found.====？页面取得是ProductList不是Map*/public Collection<CartItem> getItems() {return items.values();}public Map<String, CartItem> getItemsMap() {return items;}public List<CartItem> getItems2() {Collection<CartItem> collection = items.values();//collection.remove(o)//okreturn (List<CartItem>) items.values();}//public void delByPid(String pid){items.remove(pid);}public void setItems(Map<String,CartItem> items) {this.items = items;}/*public void setCartItems(Map<String,CartItem> items) {this.items = items;}==========购物车添加CartItem，不需要每次都添加一个Map集合（不需要set）。改进：新建一个Map。每次Map里添加一个。*/public void addCartItem(CartItem cartItem ) {/*//===v1【每种商品只能添加一个，pid 重复，添加覆盖】this.items.put(cartItem.getPro().getPid(), cartItem);*///===v2CartItem im = items.get(cartItem.getPro().getPid());if (im==null) {items.put(cartItem.getPro().getPid(), cartItem);} else {cartItem.setCount(cartItem.getCount()+im.getCount());items.put(cartItem.getPro().getPid(), cartItem);}}public int getScore() {return (int) (getTotalMoney()/10);}public void setScore(int score) {this.score = score;}public double getTotalMoney() {/*//===v1 for (int i = 0; i < items.size(); i++) {totalMoney+=items.get(i).getTotal();}*//*//===v2Collection values =  items.values();System.out.println(values);for (Iterator iterator = values.iterator(); iterator.hasNext();) {Object object = (Object) iterator.next();System.out.println();}*/int total=0;//遍历所有购物项，将小计相加。Collection<CartItem> item =  items.values();System.out.println(item);for (CartItem value: item) {total+=value.getTotal();}return total;}/*public void setTotalMoney(double totalMoney) {this.totalMoney = totalMoney;}*/@Overridepublic String toString() {return "Cart [items=" + items + ", score=" + getScore() + ", totalMoney=" + getTotalMoney() + "]";}}

订单功能：（和购物车思想类似）

package cn.itcast.domain;import java.util.List;public class OrderItem {private String  itemid;private int count;private double subtotal;/*private List product ;private List order ;*/private Product product ;private Orders order ;public OrderItem() {super();// TODO Auto-generated constructor stub}public OrderItem(String itemid, int count, double subtotal, Product product, Orders order) {super();this.itemid = itemid;this.count = count;this.subtotal = subtotal;this.product = product;this.order = order;}public String getItemid() {return itemid;}public void setItemid(String itemid) {this.itemid = itemid;}public int getCount() {return count;}public void setCount(int count) {this.count = count;}public double getSubtotal() {//return subtotal;//====bean 加入业务轻逻辑。subtotal=product.getShop_price()*count;return subtotal;}/* //===subtotal是计算出来的，不用set赋值 public void setSubtotal(double subtotal) {this.subtotal = subtotal;}*/public Product getProduct() {return product;}public void setProduct(Product product) {this.product = product;}public Orders getOrder() {return order;}public void setOrder(Orders order) {this.order = order;}@Overridepublic String toString() {return "OrderItem [itemid=" + itemid + ", count=" + count + ", subtotal=" + subtotal + ", product=" + product+ ", order=" + order + "]";}}

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package cn.itcast.domain;import java.util.Collection;import java.util.Date;import java.util.LinkedHashMap;public class Orders {private String oid;private Date date;private double total;private int state;//对着关系图写。sql语句找起来还是费点劲的。private String address;private String name;private String telephone;//private String uid ;private User user;//================#######===========【加深理解：Bean属性有 两种。业务需要，表字段映射】//订单和订单项。1:n关系。所以Orders表里不需要添加 itemid属性。//但是业务逻辑上： Orders 包含 多个OrderItem，Orders本就是用来封装OderItem的。//（和分页 PageBean类似，封装数据,作用只不过是：方便页面取值）//所以：和【Cart封装CartItem一样，这里也要添加一个Map<Stirng pid,OderItem item> 的map 封装多个订单项。 】 //===所以说：这个map属性是 业务需要。其他属性是表字段映射。private LinkedHashMap<String,OrderItem> orderItems = new LinkedHashMap<String,OrderItem>();public Collection<OrderItem> getOrderItems() {return orderItems.values();}public void setOrderItems(LinkedHashMap<String, OrderItem> map) {this.orderItems = map;}public Orders() {super();}public Orders(String oid, Date date, double total, int state, String address, String name, String telephone,User user) {super();this.oid = oid;this.date = date;this.total = total;this.state = state;this.address = address;this.name = name;this.telephone = telephone;this.user = user;}public String getOid() {return oid;}public void setOid(String oid) {this.oid = oid;}public Date getDate() {return date;}public void setDate(Date date) {this.date = date;}public double getTotal() {Collection<OrderItem> items = getOrderItems();int total=0;for (OrderItem item : items) {total += item.getSubtotal();}return total;}public void setTotal(double total) {this.total = total;}public int getState() {return state;}public void setState(int state) {this.state = state;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getTelephone() {return telephone;}public void setTelephone(String telephone) {this.telephone = telephone;}public User getUser() {return user;}public void setUser(User user) {this.user = user;}@Overridepublic String toString() {return "Orders [oid=" + oid + ", date=" + date + ", total=" + getTotal() + ", state=" + state + ", address="+ address + ", name=" + name + ", telephone=" + telephone + ", user=" + user + "]";}}