Decoration Mode 2-Invoice system

[keywords]:java,design pattern, design pattern, Java and pattern learning, decorator, decoration mode

[Environment]:staruml5.0 + JDK6

[Author]:winty (wintys@gmail.com)

[Body]:

　　Package pattern.decorator.order;
　　Import java.util.*;
　　Import java.text.*;
　　/** * Decoration mode (decorator pattern): Invoice System * * Invoice is divided into three parts: Invoice head, invoice body, invoice end.
　　* Where the invoice header and the end of the invoice are likely to change frequently.　　　 * Run Result: Bill Gates 2009-6-6 ==================== name price milk 5.4 10￥54.00 Bread 7.3 3￥21.90 Salad 4.2 2￥8.40 ==================== Total price:￥84.30 client: Bill Gates Time: 2009 -6-6 ==================== Name price milk 5.4 10￥54.00 Bread 7.3 3￥21.90 ======= ============= Total price:￥75.90 * @version 2009-06-06 * @author winty (wintys@gmail.com)/public class Orderte
　　 　　　 　st{public static void Main (string[] args) {//Create Item milk = new Item ("Milk", 5.4,10);
　　 　　　 　Item bread = new Item ("Bread", 7.3, 3);
　　 　　　 　Item salad = new Item ("Salad", 4.2, 2);
　　 　　　 　Create invoice Order sales = new SalesOrder ();
　　 　　　 　Sales.setcustomername ("Bill Gates");
　　 Sales.setsalesdate (New Date ());　　　 　Sales.additem (milk);
　　 　　　 　Sales.additem (bread);
　　 　　　 　
　　 　　　 　Order of order;
　　 　　　 　Add the invoice to the tail, then output order = new Footerdecorator (new Headerdecorator (sales));
　　 　　　 　The decorated order is transparent to the client Order.additem (salad);
　　 　　　 　Order.print ();
　　 　　　 　System.out.println ("");
　　 　　　 　Different packing order, output order of the same sequence = new Anotherheaderdecorator (new Footerdecorator (sales));
　　 　　　 　The Remove Order.removeitem (salad) can also be safely invoked;　　 　　　 　
　　 　Order.print ();
　　 　}/** * Product/class item{private String name; Private double price;//unit price private int amount;//Purchase quantity public item () {} public item (String name, double pric
　　 　　　 　e, int amount) {this.name = name;
　　 　　　 　This.price = Price;
　　 　This.amount = amount;
　　 　Public String GetName () {return this.name;
　　 　public void SetName (String name) {this.name = name;
　　 　Public double GetPrice () {return this.price; } public void Setprice (doublePrice) {this.price = Price;
　　 　public int Getamount () {return this.amount;
　　 　The public void Setamount (int amount) {this.amount = amount;
　　 　}/** * Abstract component Role * * order{protected list<item> items;
　　 　Private String CustomerName;
　　 　Private Date salesdate;
　　 　Public order () {items = new arraylist<item> ();
　　 　public abstract void print ();
　　 　Add merchandise public void AddItem (item item) {Items.Add (item);
　　 　//Delete merchandise public void RemoveItem (item item) {Items.remove (item);
　　 　　　 　Public double Caltotalprice () {Double total = 0.0;
　　 　　　 　iterator<item> list = Items.iterator ();
　　 　　　 　　　 　while (List.hasnext ()) {item = List.next ();
　　 　　　 　Total + = Item.getprice () * Item.getamount ();
　　 　Return to total;
　　 　Public String Getcustomername () {return customerName; public void Setcustomername (String CustomerName) {this.customername = CustomerName;
　　 　Public Date Getsalesdate () {return salesdate;
　　 　The public void Setsalesdate (Date salesdate) {this.salesdate = salesdate;
　　 　public static String FormatDate (Date mydate) {return dateformat.getdateinstance (). Format (mydate); public static String FormatCurrency (double currency) {return numberformat.getcurrencyinstance (). Format (Curre
　　 　ncy); }/** * Specific component Role/class SalesOrder extends order{/** * Output Commodity information * * @Override Publ
　　 　　　 　IC void print () {printitemheader ();
　　 　　　 　iterator<item> list = Items.iterator ();
　　 　　　 　while (List.hasnext ()) {print (List.next ()); }/** * Output individual product information */private void print (item) {Double subtotal = Item.getamount () *item
　　 　　　 　. GetPrice ();
　　 　　　 　String str = item.getname () + "T";
　　 　　　 　STR + + item.getprice () + "T"; str = Item.getamounT () + "" T ";
　　 　　　 　str = order.formatcurrency (subtotal);
　　 　System.out.println (str);
　　 　　　 　/** * Output Item Header/private void Printitemheader () {String Header = "T price" T number "T";
　　 　System.out.println (header);
　　}/** * Abstract decorative role * * Only the method (Caltotalprice ()) that is reassigned to the invocation, * or the method (Setcustomername () that replicates the data), can be invoked safely by the multiple decorated subclass.
　　 　* * Abstract class Orderdecorator extends order{private order;
　　 　　　 　Public Orderdecorator (order) {this.order = order;
　　 　　　 　No "delegation" was used to copy the value directly This.setcustomername (Order.getcustomername ());
　　 　This.setsalesdate (Order.getsalesdate ());
　　 　@Override public void print () {order.print ();
　　 　@Override public Double Caltotalprice () {return order.caltotalprice ();
　　 　@Override public void AddItem (item) {Order.additem (item);
　　 　@Override public void RemoveItem (item) {Order.removeitem (item); 
}　　/** * Print Invoice Header decoration */class Headerdecorator extends orderdecorator{public headerdecorator (order) {
　　 　Super (order);
　　 　　　 　@Override public void print () {printheader ();
　　 　Super.print ();
　　 　　　 　private void Printheader () {String header = Getcustomername () + "T";
　　 　　　 　Header + order.formatdate (Getsalesdate ());
　　 　　　 　System.out.println (header);
　　 　System.out.println ("====================");
　　 　　　 　}/** * Print invoice at the end of the decoration */class Footerdecorator extends orderdecorator{public footerdecorator (order) {
　　 　Super (order);
　　 　　　 　@Override public void print () {super.print ();
　　 　Printfooter ();
　　 　　　 　private void Printfooter () {String total;
　　 　　　 　Total = Order.formatcurrency (Caltotalprice ());
　　 　　　 　System.out.println ("====================");
　　 　SYSTEM.OUT.PRINTLN ("Total Price:" + total); }/** * Another kind of print invoice Header decoration class/class Anotherheaderdecorator extends Orderdecorator{Public Anotherheaderdecorator (order) {super (order);
　　 　　　 　@Override public void print () {printheader ();
　　 　Super.print ();
　　 　　　 　private void Printheader () {String header;
　　 　　　 　Header = "Customer:" + getcustomername () + "n";
　　 　　　 　Header = + "time:" + order.formatdate (Getsalesdate ());
　　 　　　 　System.out.println (header);
　　 　System.out.println ("===================="); } 　　}