设计模式第三次作业
GitHub地址:https://github.com/zlxzlxzlx/DP3
要求：某商品管理系统的商品名称存储在一个字符串数组中，现需要自定义一个双向迭代器（MyIterator）实现对该商品名称数组的双向（向前和向后）遍历。使用Iterator模式来设计。
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关键类java源码及注释：
public interface abstructIterator { public void next(); public boolean isLast(); public void previous(); public boolean isFirst(); public String getNext(); public String getPrevious(); } public interface abstructProduct { abstructIterator createIterator();} public class Product implements abstructProduct{ private Object[] obj={"苹果","梨","橙子","香蕉"}; @Override public abstructIterator createIterator() { return new MyIterator(); } private class MyIterator implements abstructIterator{ private int index1; private int index2; public MyIterator() { index1 = 0; index2 = obj.length - 1; } @Override public void next() { if(index1 -1) { index2--; } } @Override public boolean isFirst() { return index2==-1; } @Override public String getNext() { return (String) obj[index1]; } @Override public String getPrevious() { return (String) obj[index2]; } } } public class client { public static void main(String[] args) { abstructIterator iterator; abstructProduct product =new Product(); iterator=product.createIterator(); while (!iterator.isLast()) { System.out.print(iterator.getNext()); System.out.print(" "); iterator.next(); } System.out.println(); while (!iterator.isFirst()) { System.out.print(iterator.getPrevious()); System.out.print(" "); iterator.previous(); } }} 输出结果：
苹果 梨 橙子 香蕉 香蕉 橙子 梨 苹果
要求：某公司欲开发一个基于Windows平台的公告板系统，系统提供主菜单（Menu）其中有菜单项（MenuItem）。通过Menu类的addMenuItem()方法增加菜单项。菜单项的打开方法是click(）,每个菜单项包含一个抽象命令类，具体命令类包括OpenCommand()、CreateCommand()、EditCommand()等，命令类具有一个execute()方法，用于调用公告板系统界面类（BoardScreen()）的open()、create()、edit()）等方法。使用Command模式来设计。
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关键类java源码及注释：
public interface abstructCommand { public void execute();} public class CreateCommand implements abstructCommand{ private BoardScreen bs; public CreateCommand( BoardScreen bs){ this.bs=bs; } @Override public void execute() { bs.create(); }} public class EditCommand implements abstructCommand{ private BoardScreen bs; public EditCommand ( BoardScreen bs){ this.bs=bs; } @Override public void execute() { bs.edit(); }} public class OpenCommand implements abstructCommand{ private BoardScreen bs; public OpenCommand ( BoardScreen bs){ this.bs=bs; } @Override public void execute() { bs.open(); }} public class MenuItem { private abstructCommand command; public MenuItem(abstructCommand command){ this.command=command; } public void click(){ this.command.execute(); }} import java.util.ArrayList;public class Menu { private ArrayList public class BoardScreen { public void open(){ System.out.println("open被调用"); } public void create(){ System.out.println("create被调用"); } public void edit(){ System.out.println("edit被调用"); }} public class client { public static void main(String[] args) { Menu menu=new Menu(); BoardScreen bs = new BoardScreen(); abstructCommand oc=new OpenCommand(bs ); MenuItem item1=new MenuItem(oc); menu.addMenuItem(item1); abstructCommand cc=new CreateCommand(bs ); MenuItem item2=new MenuItem(cc); menu.addMenuItem(item2); abstructCommand ec=new EditCommand(bs ); MenuItem item3=new MenuItem(ec); menu.addMenuItem(item3); menu.clickMenuItem(0); menu.clickMenuItem(1); menu.clickMenuItem(2); }} 输出结果：
open被调用create被调用edit被调用
要求：某论坛系统欲增加一个虚拟聊天室，允许论坛会员通过该聊天室进行信息交流，普通会员（CommonMember）可以给其他会员发送文本信息，钻石会员（DiamondMember）可以给其他会员发送文本和图片信息。该聊天室可以对不雅字符进行过滤，如“TMD”等字符，还可以对发送图片大小进行控制。使用Mediator模式来设计。
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关键类java源码及注释：
public abstract class abstructChatRoom { public abstract void addRoom(Member member); public abstract void sendText(String form,String to,String text); public abstract void sendImage(String form,String to,String image);} import java.util.HashMap;import java.util.Map;public class ChatRoom extends abstructChatRoom{ Map map=new HashMap (); @Override public void addRoom(Member member) { map.put(member.getName(), member); member.setAbstructChatRoom(this); } @Override public void sendText(String from, String to, String text) { Member memberToText=map.get(to); memberToText.reciveText(from, text); } @Override public void sendImage(String from, String to, String image) { Member memberToImage=map.get(to); memberToImage.reciveImage(from, image); }} public abstract class Member { protected String name; protected abstructChatRoom abstructChatRoom; public Member(String name) { this.name=name; } public String getName() { return name; } public abstructChatRoom getAbstructChatRoom() { return abstructChatRoom; } public void setAbstructChatRoom(abstructChatRoom abstructChatRoom) { this.abstructChatRoom = abstructChatRoom; } public abstract void sendText(String to,String Text); public abstract void sendImage(String to,String Image); public void reciveText(String from,String Text){ System.out.println(this.name+"接收来自"+from+"的文本："+Text); } public void reciveImage(String from,String Image){ System.out.println(this.name+"接收来自"+from+"的图片："+Image); }} public class DiamondMember extends Member{ public DiamondMember(String name){ super(name); } @Override public void sendText(String to, String Text) { System.out.println(this.name+"向"+to+"发送的文本："+Text); super.abstructChatRoom.sendText(this.name, to, Text); } @Override public void sendImage(String to, String Image) { System.out.println(this.name+"向"+to+"发送的图片："+Image); super.abstructChatRoom.sendImage(this.name, to, Image); }} public class CommonMember extends Member { public CommonMember(String name){ super(name); } @Override public void sendText(String to, String Text) { System.out.println(this.name+"向"+to+"发送的文本："+Text); super.abstructChatRoom.sendText(this.name, to, Text); } @Override public void sendImage(String to, String Image) { System.out.println("对不起您没有发送图片的权限"); }} public class client { public static void main(String[] args) { abstructChatRoom chatRoom=new ChatRoom(); Member member1=new CommonMember("zlx"); chatRoom.addRoom(member1); Member member2=new DiamondMember("lj"); chatRoom.addRoom(member2); Member member3=new CommonMember("tf"); chatRoom.addRoom(member3); member1.sendText("lj", "hello"); member1.sendImage("ft", "image"); member2.sendText("zlx", "fine"); member3.sendText("zlx", "thank"); member3.sendImage("lj", "image"); }} 输出结果：
zlx向lj发送的文本：hellolj接收来自zlx的文本：hello对不起您没有发送图片的权限lj向zlx发送的文本：finezlx接收来自lj的文本：finetf向zlx发送的文本：thankzlx接收来自tf的文本：thank对不起您没有发送图片的权限
要求：设计一个网上书店，对系统中所有的计算机类图书（ComputerBook）每本都有10%的折扣，语言类图书（LanguageBook）每本都有2元的折扣，小说类图书（NovelBook）每100元有15元的折扣。使用Strategy模式来设计。
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关键类java源码及注释：
public interface BookStrategy { double calcPrice(double bookPrice); } public class ComputerBook implements BookStrategy{ @Override public double calcPrice(double bookPrice) { System.out.println("ComputerBook 10% discount. "); return bookPrice*0.9; }} public class LanguageBook implements BookStrategy{ @Override public double calcPrice(double bookPrice) { System.out.println("LanguageBook-2.0 discount."); return bookPrice-2.0; }} public class NovelBook implements BookStrategy{ @Override public double calcPrice(double bookPrice) { System.out.println("NovelBook100.00-15.00"); int bp = (int)bookPrice; return bookPrice - (double)(bp / 100 * 15); }} public class Price { private BookStrategy strategy; public void setStrategy(BookStrategy strategy){ this.strategy=strategy; } public double calcPrice(double bookPrice){ return this.strategy.calcPrice(bookPrice); }} public class client { public static void main(String[] args) { Price price1=new Price(); BookStrategy strategy1=new ComputerBook(); price1.setStrategy(strategy1); double p1=123; System.out.println("计算机类图书原价"+p1+"计算机类图书折扣后:"+price1.calcPrice(p1)); Price price2=new Price(); BookStrategy strategy2=new LanguageBook(); price2.setStrategy(strategy2); double p2=456; System.out.println("语言类图书原价"+p2+"语言类图书折扣后:"+price2.calcPrice(p2)); Price price3=new Price(); BookStrategy strategy3=new NovelBook(); price3.setStrategy(strategy3); double p3=789; System.out.println("小说类图书"+p3+"小说类图书折扣后:"+price3.calcPrice(p3)); }} 输出结果：
ComputerBook 10% discount. 计算机类图书原价123.0计算机类图书折扣后:110.7LanguageBook-2.0 discount.语言类图书原价456.0语言类图书折扣后:454.0NovelBook100.00-15.00小说类图书789.0小说类图书折扣后:684.0