中介者模式又叫调解者模式或调停者模式,是行为型设计模式之一。
生活中的中介者的作用就是连接两方的一个桥梁,比如房产中介,买房的只需跟中介打交道,然后买房的也跟着中介打交道,
喵了个呜的小宇宙
没有中介的时候是这样的:
每个买房的和卖房的都要和很多对方打交道,有了新的买房人,这些卖房的都得知道才能去和他联系。
有了中介者之后:
所有买房的和卖房的都只需要跟中介者一个人打交道,买房的不需要知道卖房的是什么人,有多少卖房的等等。都省事了很多。
通过中介者包装一系列对象的交互,使得这些对象不必相互显式引用,从而使它们可以松散耦合。
当某些对象之间的作用发生变化是,不会立即影响其他对象间的作用,保证这些作用协议彼此独立的变化。
中介者模式将多对多的相互作用转化为一堆多的相互作用。
模板代码:
抽象的中介者:
- public interfaceMediator {voidchange();
- }
具体的中介者:
- public class ConcreteMediator implements Mediator{
- publicConcreteColleagueA concreteColleagueA;publicConcreteColleagueB concreteColleagueB;public void setConcreteColleagueA(ConcreteColleagueA concreteColleagueA) {this.concreteColleagueA = concreteColleagueA;
- }public void setConcreteColleagueB(ConcreteColleagueB concreteColleagueB) {this.concreteColleagueB = concreteColleagueB;
- }@Override
- public void change() {
- concreteColleagueA.action();
- concreteColleagueB.action();
- }
- }
抽象的同事:
- public abstract classColleague {publicMediator mediator;public Colleague(Mediator mediator) {this.mediator = mediator;
- }public abstract void action();
- }
具体的同事:
- public class ConcreteColleagueA extends Colleague{
- public ConcreteColleagueA(Mediator mediator) {super(mediator);
- }@Override
- public void action() {
- System.out.println("交给中介做A的事情");
- }
- }public class ConcreteColleagueB extends Colleague{
- public ConcreteColleagueB(Mediator mediator) {super(mediator);
- }@Override
- public void action() {
- System.out.println("交给中介做B的事情");
- }
- }
以电脑为例子。CPU,显卡,内存等零件的交互都是通过主板实现的,而且每个零件只需要做好自己的工作,不需要知道其他零件是什么。所以主板可以作为他们的中介者。
抽象的中介者:
- public abstract classMediator {public abstract void change(Colleague colleague);
- }
具体的中介者,主板:
- public class MainBoard extends Mediator{
- privateCDDevice cdDevice;privateCPU cpu;privateGraphicsCard graphicsCard;privateSoundCard soundCard ;@Override
- public void change(Colleague colleague) {if(colleague==cdDevice){
- handleCD((CDDevice) colleague);
- }if(colleague==cpu){
- handleCPU((CPU) colleague);
- }
- }private void handleCD(CDDevice cdDevice){
- cpu.decodeData(cdDevice.read());
- }private void handleCPU(CPU cpu){
- soundCard.playSound(cpu.getDataSound());
- graphicsCard.vidoePlay(cpu.getDataVideo());
- }public void setCdDevice(CDDevice cdDevice) {this.cdDevice = cdDevice;
- }public void setCpu(CPU cpu) {this.cpu = cpu;
- }public void setGraphicsCard(GraphicsCard graphicsCard) {this.graphicsCard = graphicsCard;
- }public void setSoundCard(SoundCard soundCard) {this.soundCard = soundCard;
- }
- }
抽象的零件:
- public abstract classColleague {publicMediator mediator;public Colleague(Mediator mediator) {this.mediator = mediator;
- }
- }
具体的零件:
- public class CPU extends Colleague {
- private String dataVideo,
- dataSound;
- public CPU(Mediator mediator) {
- super(mediator);
- }
- public String getDataVideo() {
- return dataVideo;
- }
- public String getDataSound() {
- return dataSound;
- }
- //解析数据,分割音频和视频
- public void decodeData(String data) {
- String[] tmp = data.split(",");
- dataVideo = tmp[0];
- dataSound = tmp[1];
- mediator.change(this);
- }
- }
- public class CDDevice extends Colleague{
- privateString data;public CDDevice(Mediator mediator) {super(mediator);
- }publicStringread(){returndata;
- }public void load(){
- data="视频数据,音频数据";
- mediator.change(this);
- }
- }
- public class GraphicsCard extends Colleague{
- public GraphicsCard(Mediator mediator) {super(mediator);
- }public void vidoePlay(String data){
- System.out.println("播放视频:"+data);
- }
- }
- public class SoundCard extends Colleague{
- public SoundCard(Mediator mediator) {super(mediator);
- }public void playSound(String data){
- System.out.println("播放音频:"+ data);
- }
- }
在面向对象编程中,一个类必然会与其他类产生依赖关系,当依赖关系错综复杂时,可以考虑用中介者模式进行解耦。
来源: http://blog.csdn.net/qq_25806863/article/details/69396448