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Head-First-Design-Patterns-master\src\headfirst\designpatterns\adapter
Head-First-Design-Patterns-master\src\headfirst\designpatterns\facade
什么是适配器:
在欧洲国家使用美国制造的笔记本电脑,需要使用一个交流电的适配器,改变插座的接口,以符合美式笔记本电脑的需求。
使用一只火鸡来冒充鸭子
public interface Duck {
public void quack();
public void fly();
}
public class MallardDuck implements Duck {
public void quack() {
System.out.println("Quack");
}
public void fly() {
System.out.println("I'm flying");
}
}
public interface Turkey {
public void gobble();
public void fly();
}
public class WildTurkey implements Turkey {
public void gobble() {
System.out.println("Gobble gobble");
}
public void fly() {
System.out.println("I'm flying a short distance");
}
}
public class TurkeyAdapter implements Duck {
Turkey turkey;
public TurkeyAdapter(Turkey turkey) {
this.turkey = turkey;
}
public void quack() {
turkey.gobble();
}
public void fly() {
for(int i=0; i < 5; i++) {
turkey.fly();
}
}
}
public class DuckTestDrive {
public static void main(String[] args) {
MallardDuck duck = new MallardDuck();
WildTurkey turkey = new WildTurkey();
Duck turkeyAdapter = new TurkeyAdapter(turkey);
System.out.println("The Turkey says...");
turkey.gobble();
turkey.fly();
System.out.println("\nThe Duck says...");
testDuck(duck);
System.out.println("\nThe TurkeyAdapter says...");
testDuck(turkeyAdapter);
}
static void testDuck(Duck duck) {
duck.quack();
duck.fly();
}
}
定义:将一个类的几口,转换成客户期望的另一个接口,适配器让原本不兼容的类可以合作无间。
适配器分为:
1.对象适配器
2.类适配器:在需要多重继承的时候
此处参考博客:https://blog.csdn.net/qq_36982160/article/details/79965027
装饰者不改变接口,但加入责任
适配器将一个接口转变成另一个接口
外观模式让接口更简单
外观模式定义:提供了一个统一的接口,用来访问子系统中的一群接口,外观定义了一个高层接口,让子系统更容易使用。
//每一个方法都是将其他方法组合在一起,这样一个方法可以完成一系列操作。如看电影操作包括:打开电视,打开公放,拿爆米花等操作。
public class HomeTheaterFacade {
Amplifier amp;
Tuner tuner;
DvdPlayer dvd;
CdPlayer cd;
Projector projector;
TheaterLights lights;
Screen screen;
PopcornPopper popper;
public HomeTheaterFacade(Amplifier amp,
Tuner tuner,
DvdPlayer dvd,
CdPlayer cd,
Projector projector,
Screen screen,
TheaterLights lights,
PopcornPopper popper) {
this.amp = amp;
this.tuner = tuner;
this.dvd = dvd;
this.cd = cd;
this.projector = projector;
this.screen = screen;
this.lights = lights;
this.popper = popper;
}
public void watchMovie(String movie) {
System.out.println("Get ready to watch a movie...");
popper.on();
popper.pop();
lights.dim(10);
screen.down();
projector.on();
projector.wideScreenMode();
amp.on();
amp.setDvd(dvd);
amp.setSurroundSound();
amp.setVolume(5);
dvd.on();
dvd.play(movie);
}
public void endMovie() {
System.out.println("Shutting movie theater down...");
popper.off();
lights.on();
screen.up();
projector.off();
amp.off();
dvd.stop();
dvd.eject();
dvd.off();
}
public void listenToCd(String cdTitle) {
System.out.println("Get ready for an audiopile experence...");
lights.on();
amp.on();
amp.setVolume(5);
amp.setCd(cd);
amp.setStereoSound();
cd.on();
cd.play(cdTitle);
}
public void endCd() {
System.out.println("Shutting down CD...");
amp.off();
amp.setCd(cd);
cd.eject();
cd.off();
}
public void listenToRadio(double frequency) {
System.out.println("Tuning in the airwaves...");
tuner.on();
tuner.setFrequency(frequency);
amp.on();
amp.setVolume(5);
amp.setTuner(tuner);
}
public void endRadio() {
System.out.println("Shutting down the tuner...");
tuner.off();
amp.off();
}
}
最少知识原则告诉我们:要减少对象之间的交互,只留下几个“密友”。
遵守此原则:
调用属于一下范围的方法:
该对象本身
被当做方法的参数而传递进来的对象
此方法所创建或实例化的任何对象
对象的任何组件
如果某对象是调用其他的方法的返回结果,不要调用该对象的方法!