一、中介者模式介紹
![](https://img.laitimes.com/img/9ZDMuAjOiMmIsIjOiQnIsISPrdEZwZ1Rh5WNXp1bwNjW1ZUba9VZwlHdsATOfd3bkFGazxCMx8VesATMfhHLlN3XnxCMwEzX0xiRGZkRGZ0Xy9GbvNGLpZTY1EmMZVDUSFTU4VFRR9Fd4VGdsYTMfVmepNHLrJXYtJXZ0F2dvwVZnFWbp1zczV2YvJHctM3cv1Ce-cmbw5COldzMlJmM1QWYjZDZ1YzN5U2NmVGNxADNlZDNhdjZm9CXwIzLcdDMxIDMy8CXn9Gbi9CXzV2Zh1WavwVbvNmLvR3YxUjL1M3Lc9CX6MHc0RHaiojIsJye.png)
需求:
UML類圖:
代碼實作(Java):
//同僚抽象類
public abstract class Colleague {
private Mediator mediator;
public String name;
public Colleague(Mediator mediator, String name) {
this.mediator = mediator;
this.name = name;
}
public Mediator GetMediator() {
return this.mediator;
}
public abstract void SendMessage(int stateChange);
}
//具體的同僚類
public class Alarm extends Colleague {
//構造器
public Alarm(Mediator mediator, String name) {
super(mediator, name);
//在建立Alarm 同僚對象時,将自己放入到ConcreteMediator 對象中[集合]
mediator.Register(name, this);
}
public void SendAlarm(int stateChange) {
SendMessage(stateChange);
}
@Override
public void SendMessage(int stateChange) {
//調用的中介者對象的getMessage
this.GetMediator().GetMessage(stateChange, this.name);
}
}
public class CoffeeMachine extends Colleague {
public CoffeeMachine(Mediator mediator, String name) {
super(mediator, name);
mediator.Register(name, this);
}
@Override
public void SendMessage(int stateChange) {
this.GetMediator().GetMessage(stateChange, this.name);
}
public void StartCoffee() {
System.out.println("It's time to startcoffee!");
}
public void FinishCoffee() {
System.out.println("After 5 minutes!");
System.out.println("Coffee is ok!");
SendMessage(0);
}
}
public class TV extends Colleague {
public TV(Mediator mediator, String name) {
super(mediator, name);
mediator.Register(name, this);
}
@Override
public void SendMessage(int stateChange) {
this.GetMediator().GetMessage(stateChange, this.name);
}
public void StartTv() {
System.out.println("It's time to StartTv!");
}
public void StopTv() {
System.out.println("StopTv!");
}
}
public class Curtains extends Colleague {
public Curtains(Mediator mediator, String name) {
super(mediator, name);
mediator.Register(name, this);
}
@Override
public void SendMessage(int stateChange) {
this.GetMediator().GetMessage(stateChange, this.name);
}
public void UpCurtains() {
System.out.println("I am holding Up Curtains!");
}
}
public abstract class Mediator {
//将給中介者對象,加入到集合中
public abstract void Register(String colleagueName, Colleague colleague);
//接收消息, 具體的同僚對象發出
public abstract void GetMessage(int stateChange, String colleagueName);
public abstract void SendMessage();
}
import java.util.HashMap;
//具體的中介者類
public class ConcreteMediator extends Mediator {
//集合,放入所有的同僚對象
private HashMap<String, Colleague> colleagueMap;
private HashMap<String, String> interMap;
public ConcreteMediator() {
colleagueMap = new HashMap<String, Colleague>();
interMap = new HashMap<String, String>();
}
@Override
public void Register(String colleagueName, Colleague colleague) {
colleagueMap.put(colleagueName, colleague);
if (colleague instanceof Alarm) {
interMap.put("Alarm", colleagueName);
} else if (colleague instanceof CoffeeMachine) {
interMap.put("CoffeeMachine", colleagueName);
} else if (colleague instanceof TV) {
interMap.put("TV", colleagueName);
} else if (colleague instanceof Curtains) {
interMap.put("Curtains", colleagueName);
}
}
//具體中介者的核心方法
//1. 根據得到消息,完成對應任務
//2. 中介者在這個方法,協調各個具體的同僚對象,完成任務
@Override
public void GetMessage(int stateChange, String colleagueName) {
//處理鬧鐘發出的消息
if (colleagueMap.get(colleagueName) instanceof Alarm) {
if (stateChange == 0) {
((CoffeeMachine) (colleagueMap.get(interMap
.get("CoffeeMachine")))).StartCoffee();
((TV) (colleagueMap.get(interMap.get("TV")))).StartTv();
} else if (stateChange == 1) {
((TV) (colleagueMap.get(interMap.get("TV")))).StopTv();
}
} else if (colleagueMap.get(colleagueName) instanceof CoffeeMachine) {
((Curtains) (colleagueMap.get(interMap.get("Curtains"))))
.UpCurtains();
} else if (colleagueMap.get(colleagueName) instanceof TV) {//如果TV發現消息
} else if (colleagueMap.get(colleagueName) instanceof Curtains) {
//如果是以窗簾發出的消息,這裡處理...
}
}
@Override
public void SendMessage() {
}
}
public class ClientTest {
public static void main(String[] args) {
//建立一個中介者對象
Mediator mediator = new ConcreteMediator();
//建立Alarm 并且加入到 ConcreteMediator 對象的HashMap
Alarm alarm = new Alarm(mediator, "alarm");
//建立了CoffeeMachine 對象,并 且加入到 ConcreteMediator 對象的HashMap
CoffeeMachine coffeeMachine = new CoffeeMachine(mediator,
"coffeeMachine");
//建立 Curtains , 并 且加入到 ConcreteMediator 對象的HashMap
Curtains curtains = new Curtains(mediator, "curtains");
TV tV = new TV(mediator, "TV");
//讓鬧鐘發出消息
alarm.SendAlarm(0);
coffeeMachine.FinishCoffee();
alarm.SendAlarm(1);
}
}
三、中介者模式注意事項和細節