设计模式--中介者模式

实验19：中介者模式

本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：

1、理解中介者模式的动机，掌握该模式的结构；

2、能够利用中介者模式解决实际问题。

[实验任务]：虚拟聊天室

在“虚拟聊天室”实例中增加一个新的具体聊天室类和一个新的具体会员类，要求如下：

1. 新的具体聊天室中发送的图片大小不得超过20M。

2. 新的具体聊天室中发送的文字长度不得超过100个字符。

3. 新的具体会员类可以发送图片信息和文本信息。

4. 新的具体会员类在发送文本信息时，可以在信息后加上时间。

修改客户端测试类，注意原有系统类代码和客户端代码的修改。

源代码

/*** 抽象聊天室*/
public abstract class AbstractChatroom
{public abstract void register(Member member);public abstract void sendText(String from,String to,String message);public abstract void sendImage(String from,String to,String image);
}import java.util.Hashtable;public class ChatGroup extends AbstractChatroom
{private Hashtable members = new Hashtable();@Overridepublic void register(Member member){if (!members.contains(member)){members.put(member.getName(), member);member.setChatroom(this);}}@Overridepublic void sendText(String from, String to, String message){Member member = (Member) members.get(to);String newMessage = message;//模拟不雅字符过滤newMessage = message.replaceAll("日", "*");member.receiveText(from, newMessage);}@Overridepublic void sendImage(String from, String to, String image){Member member = (Member) members.get(to);//模拟图片大小判断if (image.length() > 5){System.out.println("图片太大，发送失败！");} else{member.receiveImage(from, image);}}
}import java.util.Hashtable;/*** 新的具体聊天室* @author mendianyu*/
public class AdvancedChatGroup extends AbstractChatroom
{private Hashtable members = new Hashtable();@Overridepublic void register(Member member){if (!members.contains(member)){members.put(member.getName(), member);member.setChatroom(this);}}@Overridepublic void sendText(String from, String to, String message){Member member = (Member) members.get(to);//消息的文字长度不得超过100if (message.length() > 100){System.out.println("消息太长了，发送失败!");} else{member.receiveText(from, message);}}@Overridepublic void sendImage(String from, String to, String image){Member member = (Member) members.get(to);//图片大小不得超过20Mif (image.length() > 20){System.out.println("图片太大了，发送失败!");} else{member.receiveImage(from, image);}}
}/*** 抽象用户类*/
public abstract class Member
{protected AbstractChatroom chatroom;protected String name;public Member(String name){this.name = name;}public String getName(){return name;}public void setName(String name){this.name = name;}public AbstractChatroom getChatroom(){return chatroom;}public void setChatroom(AbstractChatroom chatroom){this.chatroom = chatroom;}public abstract void sendText(String to, String message);public abstract void sendImage(String to, String image);public void receiveText(String from, String message){System.out.println(from + "发送文本给" + this.name + "，内容为：" + message);}public void receiveImage(String from, String image){System.out.println(from + "发送图片给" + this.name + "，内容为：" + image);}
}/*** 普通用户类*/
public class CommonMember extends Member
{public CommonMember(String name){super(name);}@Overridepublic void sendText(String to, String message){System.out.println("普通会员发送信息：");//发送文本chatroom.sendText(name, to, message);}@Overridepublic void sendImage(String to, String image){System.out.println("普通会员不能发送图片！");}
}/*** 钻石会员类*/
public class DiamondMember extends Member
{public DiamondMember(String name){super(name);}@Overridepublic void sendText(String to, String message){System.out.println("钻石会员发送信息：");//发送文本chatroom.sendText(name, to, message);}@Overridepublic void sendImage(String to, String image){System.out.println("钻石会员发送图片：");//发送图片chatroom.sendImage(name, to, image);}
}import java.text.SimpleDateFormat;
import java.util.Date;/*** 铂金会员** @author mendianyu*/
public class AdvancedMember extends Member
{public AdvancedMember(String name){super(name);}@Overridepublic void sendText(String to, String message){System.out.println("铂金会员发送文本:");//在消息后面加上时间SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");String timestamp = dateFormat.format(new Date());message += " [" + timestamp + "]";chatroom.sendText(name, to, message);}@Overridepublic void sendImage(String to, String image){System.out.println("铂金会员发送图片");chatroom.sendImage(name, to, image);}
}public class Client
{public static void main(String[] args){//实例化一个新的聊天室AbstractChatroom advancedChatroom = new AdvancedChatGroup();Member member1, member2, member3, member4, member5;member1 = new CommonMember("张三");member2 = new DiamondMember("李四");//实例化新的会员member3 = new AdvancedMember("王五");//加入聊天室advancedChatroom.register(member1);advancedChatroom.register(member2);advancedChatroom.register(member3);member1.sendText("李四", "干嘛呢你俩？");member1.sendText("王五", "干嘛呢你俩？");member2.sendText("张三", "我在写作业");//模拟图片超过20Mmember2.sendImage("张三", "11111111111111111111111111111");member3.sendText("张三", "我在打游戏");member3.sendImage("张三", "五连绝世");member1.sendText("王五", "别打游戏了，快出来玩");//文字长度超过100，发送失败member3.sendText("张三","1. 新的具体聊天室中发送的图片大小不得超过20M。\n" +"2. 新的具体聊天室中发送的文字长度不得超过100个字符。\n" +"3. 新的具体会员类可以发送图片信息和文本信息。\n" +"4. 新的具体会员类在发送文本信息时，可以在信息后加上时间。\n" +"修改客户端测试类，注意原有系统类代码和客户端代码的修改。");}
}