CS-Notes/notes/设计模式.md

<!-- GFM-TOC -->
* [?? 1 ?? ?????????](#??-1-??-?????????)
* [?? 2 ?? ???????](#??-2-??-???????)
* [?? 3 ?? ?????](#??-3-??-?????)
* [?? 4 ?? ??????](#??-4-??-??????)
    * [4.1 ?????](#41-?????)
    * [4.2 ??????????](#42-??????????)
    * [4.3 ???????](#43-???????)
* [?? 5 ?? ??????](#??-5-??-??????)
* [?? 6 ?? ??????](#??-6-??-??????)
* [?? 7 ?? ???????????????](#??-7-??-???????????????)
    * [7.1 ????????](#71-????????)
    * [7.2 ?????](#72-?????)
* [?? 8 ?? ??<3F><>????](#??-8-??-??<3F><>????)
* [?? 9 ?? ?????????????](#??-9-??-?????????????)
    * [9.1 ????????](#91-????????)
    * [9.2 Java ??????????](#92-java-??????????)
    * [9.3 ?????](#93-?????)
* [?? 10 ?? ????](#??-10-??-????)
* [?? 11 ?? ?????? // TODO](#??-11-??-??????--todo)
* [?? 12 ?? ??????](#??-12-??-??????)
    * [12.1 MVC](#121-mvc)
        * [12.1.1 ??? MVC](#1211-???-mvc)
        * [12.1.2 Web ?<3F><>? MVC](#1212-web-?<3F><>?-mvc)
* [?? 13 ?? ?????????](#??-13-??-?????????)
* [?? 14 ?? ?????? // TODO](#??-14-??-??????--todo)
<!-- GFM-TOC -->

# ?? 1 ?? ?????????

**1. ?????????**

?????????????????????????????????<3F><>?????????????????<3F>`?<3F><>?

????????????????????????????????????????????????????

**2. ????????**

???????????????<3F><>???????????<3F><>????

**3. ????????**

??<3F><>?<3F><>?????????????????????????????????????????????????????<3F><>????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/144d28a0-1dc5-4aba-8961-ced5bc88428a.jpg)

**4. ??????**

**????<3F><>**??????<3F><>???????<3F><>???<3F><>?????????

**??????????????????????** ?????????????????????????????????????????<3F><>????????????????????????????????????????????????????????????????

????????????<3F><>???<3F><>???????????????????????<3F><>???<3F><>???????????????????<3F><>???<3F><>????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1c8ccf5c-7ecd-4b8a-b160-3f72a510ce26.png)

**???????????<3F><>??** ???????? has-a ????????????????????????????????????????<3F><>???????????????????<3F><>?????<3F><>??????????<3F><>??????????????????????????

???????????? Duck ??????? FlyBehavior ?? QuackBehavior ??performQuack() ?? performFly() ??????<3F><>???????????????????????????? Duck ??????????????????? FlyBehavior ?? QuackBehavior ???????????????????????<3F><>??

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/29574e6f-295c-444e-83c7-b162e8a73a83.jpg)

**5. ????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/e13833c8-e215-462e-855c-1d362bb8d4a0.jpg)

**6. ??????**

**??????** ???????????<3F><>???????????????????????????<3F>I????????????<3F><>?????????????????

**7. ??????**

```java
public abstract class Duck {
    FlyBehavior flyBehavior;
    QuackBehavior quackBehavior;

    public Duck(){
    }

    public void performFly(){
        flyBehavior.fly();
    }

    public void setFlyBehavior(FlyBehavior fb){
        flyBehavior = fb;
    }

    public void performQuack(){
        quackBehavior.quack();
    }

    public void setQuackBehavior(QuackBehavior qb){
        quackBehavior = qb;
    }
}
```
```java
public class MallarDuck extends Duck{
    public MallarDuck(){
        flyBehavior = new FlyWithWings();
        quackBehavior = new Quack();
    }
}
```
```java
public interface FlyBehavior {
    void fly();
}
```
```java
public class FlyNoWay implements FlyBehavior{
    @Override
    public void fly() {
        System.out.println("FlyBehavior.FlyNoWay");
    }
}
```
```java
public class FlyWithWings implements FlyBehavior{
    @Override
    public void fly() {
        System.out.println("FlyBehavior.FlyWithWings");
    }
}
```
```java
public interface QuackBehavior {
    void quack();
}
```
```java
public class Quack implements QuackBehavior{
    @Override
    public void quack() {
        System.out.println("QuackBehavior.Quack");
    }
}
```
```java
public class MuteQuack implements QuackBehavior{
    @Override
    public void quack() {
        System.out.println("QuackBehavior.MuteQuack");
    }
}
```
```java
public class Squeak implements QuackBehavior{
    @Override
    public void quack() {
        System.out.println("QuackBehavior.Squeak");
    }
}
```
```java
public class MiniDuckSimulator {
    public static void main(String[] args) {
        Duck mallarDuck = new MallarDuck();
        mallarDuck.performQuack();
        mallarDuck.performFly();
        mallarDuck.setFlyBehavior(new FlyNoWay());
        mallarDuck.performFly();
    }
}
```
??<3F><>??
```html
QuackBehavior.Quack
FlyBehavior.FlyWithWings
FlyBehavior.FlyNoWay
```

# ?? 2 ?? ???????

**1. ??????**

???????????????????????????????????????????????????????????????????????????Subject??????????????????????????Observer???????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/26cb5e7e-6fa3-44ad-854e-fe24d1a5278c.jpg)

**2. ?????**

?????<3F><>??????????????????????????????????????????????????????<3F><>????????<3F><>???????

?????????????????????????????????????????????????<3F><>??????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/5c558190-fccd-4b5e-98ed-1896653fc97f.jpg)

**3. ????????**

???????????????????????????????????????????????<3F><>???????????????????????

**4. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/760a5d63-d96d-4dd9-bf9a-c3d126b2f401.jpg)

**5. ??????**

**?????????????????????????** ????????????????????????????????????????????????????????????????????????<3F><>????????????????????<3F><>??????????<3F><>??

**6. ??????**

```java
public interface Subject {
    public void resisterObserver(Observer o);
    public void removeObserver(Observer o);
    public void notifyObserver();
}
```
```java
import java.util.ArrayList;
import java.util.List;

public class WeatherData implements Subject {
    private List<Observer> observers;
    private float temperature;
    private float humidity;
    private float pressure;

    public WeatherData() {
        observers = new ArrayList<>();
    }

    @Override
    public void resisterObserver(Observer o) {
        observers.add(o);
    }

    @Override
    public void removeObserver(Observer o) {
        int i = observers.indexOf(o);
        if (i >= 0) {
            observers.remove(i);
        }
    }

    @Override
    public void notifyObserver() {
        for (Observer o : observers) {
            o.update(temperature, humidity, pressure);
        }
    }

    public void setMeasurements(float temperature, float humidity, float pressure) {
        this.temperature = temperature;
        this.humidity = humidity;
        this.pressure = pressure;
        notifyObserver();
    }
}
```
```java
public interface Observer {
    public void update(float temp, float humidity, float pressure);
}
```
```java
public class CurrentConditionsDisplay implements Observer {
    private Subject weatherData;

    public CurrentConditionsDisplay(Subject weatherData) {
        this.weatherData = weatherData;
        weatherData.resisterObserver(this);
    }

    @Override
    public void update(float temp, float humidity, float pressure) {
        System.out.println("CurrentConditionsDisplay.update:" + temp + " " + humidity + " " + pressure);
    }
}
```
```java
public class StatisticsDisplay implements Observer {
    private Subject weatherData;

    public StatisticsDisplay(Subject weatherData) {
        this.weatherData = weatherData;
        weatherData.resisterObserver(this);
    }

    @Override
    public void update(float temp, float humidity, float pressure) {
        System.out.println("StatisticsDisplay.update:" + temp + " " + humidity + " " + pressure);
    }
}
```
```java
public class WeatherStation {
    public static void main(String[] args) {
        WeatherData weatherData = new WeatherData();
        CurrentConditionsDisplay currentConditionsDisplay = new CurrentConditionsDisplay(weatherData);
        StatisticsDisplay statisticsDisplay = new StatisticsDisplay(weatherData);

        weatherData.setMeasurements(0, 0, 0);
        weatherData.setMeasurements(1, 1, 1);
    }
}
```
??<3F><>??
```html
CurrentConditionsDisplay.update:0.0 0.0 0.0
StatisticsDisplay.update:0.0 0.0 0.0
CurrentConditionsDisplay.update:1.0 1.0 1.0
StatisticsDisplay.update:1.0 1.0 1.0
```

# ?? 3 ?? ?????

**1. ????????**

?????????????????????????????????????????????????????????????????????

**2. ??????**

?????????<3F><>??????????????????????????????????<3F><>??<3F><>?????????????

????? DarkRoast ???? Mocha ??????Mocha ??????? Whip ??????????????????????????????? cost() ????????????????? cost() ??????????????????? cost() ???????????????? DarkRoast ????? Mocha??????????? Mocha ???? DarkRoast?????????? Whip ?????? Whip ???? Mocha???????? cost() ?????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/41a4cb30-f393-4b3b-abe4-9941ccf8fa1f.jpg)

**3. ?????**

??????????????????????????????<3F><>?????????????????????????????????????????????????????????????????????????????????????????<3F><>??<3F><>?????????????????????<3F><>??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????<3F><>?<3F><>??????????<3F><>??????????????????????<3F><>??????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/3dc454fb-efd4-4eb8-afde-785b2182caeb.jpg)

**4. ???????????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/9c997ac5-c8a7-44fe-bf45-2c10eb773e53.jpg)

**5. ??????**

**??????????????????????**???????????????????????????????????<3F><>??????????????????????????????????????????????????????????????????????????????????????????????????????????????<3F><>??????????

**6. Java I/O ?<3F><>????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/2a40042a-03c8-4556-ad1f-72d89f8c555c.jpg)

**7. ???????**

```java
public interface Beverage {
    public double cost();
}
```
```java
public class HouseBlend implements Beverage{
    @Override
    public double cost() {
        return 1;
    }
}
```
```java
public class DarkRoast implements Beverage{
    @Override
    public double cost() {
        return 1;
    }
}
```
```java
public abstract class CondimentDecorator implements Beverage{
    protected Beverage beverage;
}
```
```java
public class Mocha extends CondimentDecorator {

    public Mocha(Beverage beverage) {
        this.beverage = beverage;
    }

    @Override
    public double cost() {
        return 1 + beverage.cost();
    }
}
```
```java
public class Milk extends CondimentDecorator {

    public Milk(Beverage beverage) {
        this.beverage = beverage;
    }

    @Override
    public double cost() {
        return 1 + beverage.cost();
    }
}
```
```java
public class StartbuzzCoffee {
    public static void main(String[] args) {
        Beverage beverage = new HouseBlend();
        beverage = new Mocha(beverage);
        beverage = new Milk(beverage);
        System.out.println(beverage.cost());
    }
}
```

???

```html
3.0
```

# ?? 4 ?? ??????

## 4.1 ?????

**1. ????????**

?<3F><>???? Pizza??????????????<3F><>???????????????? Pizza ????

**2. ????**

?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????<3F><>??<3F><>????????????????????????????????????????????????????????????????????????????????<3F><>????????????????????????????????<3F><>???????????<3F><>????????????<3F><>????????????????????????????????????????????????????<3F><>?????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c470eb9b-fb05-45c5-8bb7-1057dc3c16de.jpg)

**3. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/dc3e704c-7c57-42b8-93ea-ddd068665964.jpg)


**4. ???????**

```java
public interface Pizza {
    public void make();
}
```
```java
public class CheesePizza implements Pizza{
    @Override
    public void make() {
        System.out.println("CheesePizza");
    }
}
```
```java
public class GreekPizza implements Pizza{
    @Override
    public void make() {
        System.out.println("GreekPizza");
    }
}
```
```java
public class SimplePizzaFactory {
    public Pizza createPizza(String type) {
        if (type.equals("cheese")) {
            return new CheesePizza();
        } else if (type.equals("greek")) {
            return new GreekPizza();
        } else {
            throw new UnsupportedOperationException();
        }
    }
}
```
```java
public class PizzaStore {
    public static void main(String[] args) {
        SimplePizzaFactory simplePizzaFactory = new SimplePizzaFactory();
        Pizza pizza = simplePizzaFactory.createPizza("cheese");
        pizza.make();
    }
}
```

???<3F><>??

```java
CheesePizza
```

## 4.2 ??????????

**1. ????????**

????????? Pizza ???????????????????????????<3F><>?????????????????<3F><>?????????????? cheese ????? Pizza ?????????????????? Pizza ???????

**2. ??????**

?????????????????????????????????????????????????????????????????????????????

**3. ?????**

???????<3F><>???????????????????????????????<3F><>???????????????????????????????????????????????????????????????????????????????????????????<3F><>????????????????????????????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/903093ec-acc8-4f9b-bf2c-b990b9a5390c.jpg)

**4. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/664f8901-5dc7-4644-a072-dad88cc5133a.jpg)

**5. ???????**

```java
public interface Pizza {
    public void make();
}
```
```java
public interface PizzaStore {
    public Pizza orderPizza(String item);
}
```
```java
public class NYStyleCheesePizza implements Pizza{
    @Override
    public void make() {
        System.out.println("NYStyleCheesePizza is making..");
    }
}
```
```java
public class NYStyleVeggiePizza implements Pizza {
    @Override
    public void make() {
        System.out.println("NYStyleVeggiePizza is making..");
    }
}
```
```java
public class ChicagoStyleCheesePizza implements Pizza{
    @Override
    public void make() {
        System.out.println("ChicagoStyleCheesePizza is making..");
    }
}
```
```java
public class ChicagoStyleVeggiePizza implements Pizza{
    @Override
    public void make() {
        System.out.println("ChicagoStyleVeggiePizza is making..");
    }
}
```
```java
public class NYPizzaStore implements PizzaStore {
    @Override
    public Pizza orderPizza(String item) {
        Pizza pizza = null;
        if (item.equals("cheese")) {
            pizza = new NYStyleCheesePizza();
        } else if (item.equals("veggie")) {
            pizza = new NYStyleVeggiePizza();
        } else {
            throw new UnsupportedOperationException();
        }
        pizza.make();
        return pizza;
    }
}
```
```java
public class ChicagoPizzaStore implements PizzaStore {
    @Override
    public Pizza orderPizza(String item) {
        Pizza pizza = null;
        if (item.equals("cheese")) {
            pizza = new ChicagoStyleCheesePizza();
        } else if (item.equals("veggie")) {
            pizza = new ChicagoStyleVeggiePizza();
        } else {
            throw new UnsupportedOperationException();
        }
        pizza.make();
        return pizza;
    }
}
```
```java
public class PizzaTestDrive {
    public static void main(String[] args) {
        PizzaStore nyStore = new NYPizzaStore();
        nyStore.orderPizza("cheese");
        PizzaStore chicagoStore = new ChicagoPizzaStore();
        chicagoStore.orderPizza("cheese");
    }
}
```

???<3F><>??

```html
NYStyleCheesePizza is making..
ChicagoStyleCheesePizza is making..
```

## 4.3 ???????

**1. ??????**

**???????????**??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????<3F><>????? PizzaStore ???????????????????????????? Pizza ?????????????????? Pizza ?????????????????<3F><>??? Pizza ????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ddf72ca9-c0be-49d7-ab81-57a99a974c8e.jpg)

**2. ??????**

???????????????????????????????<3F><>???????????????????

**3. ?????**

????????????????????<3F><>???????????????????????????<3F><>??????????????????????????????????????????????????????????????????<3F><>?????????????????????????????????????????????????AbstractFactory ?<3F><>? CreateProductA ?? CreateProductB ????????????????????????????????????????????????????????????????????<3F>^?????????????????????????? Client ?????Client ???? AbstractFactory ????????????????????????????????????????????????<3F><>?????????Client ??????????????<3F><>??????????????????????????????????????? Cilent ????? AbstractFactory ????????????????<3F><>?

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/d301774f-e0d2-41f3-95f4-bfe39859b52e.jpg)

**4. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8785dabd-1285-4bd0-b3aa-b05cc060a24a.jpg)

**5. ???????**

```java
public interface Dough {
    public String doughType();
}
```
```java
public class ThickCrustDough implements Dough{

    @Override
    public String doughType() {
        return "ThickCrustDough";
    }
}
```
```java
public class ThinCrustDough implements Dough {
    @Override
    public String doughType() {
        return "ThinCrustDough";
    }
}
```
```java
public interface Sauce {
    public String sauceType();
}
```
```java
public class MarinaraSauce implements Sauce {
    @Override
    public String sauceType() {
        return "MarinaraSauce";
    }
}
```
```java
public class PlumTomatoSauce implements Sauce {
    @Override
    public String sauceType() {
        return "PlumTomatoSauce";
    }
}
```
```java
public interface PizzaIngredientFactory {
    public Dough createDough();
    public Sauce createSauce();
}
```
```java
public class NYPizzaIngredientFactory implements PizzaIngredientFactory{
    @Override
    public Dough createDough() {
        return new ThickCrustDough();
    }

    @Override
    public Sauce createSauce() {
        return new MarinaraSauce();
    }
}
```
```java
public class ChicagoPizzaIngredientFactory implements PizzaIngredientFactory{
    @Override
    public Dough createDough() {
        return new ThinCrustDough();
    }

    @Override
    public Sauce createSauce() {
        return new PlumTomatoSauce();
    }
}
```
```java
public class NYPizzaStore {
    private PizzaIngredientFactory ingredientFactory;

    public NYPizzaStore() {
        ingredientFactory = new NYPizzaIngredientFactory();
    }

    public void makePizza() {
        Dough dough = ingredientFactory.createDough();
        Sauce sauce = ingredientFactory.createSauce();
        System.out.println(dough.doughType());
        System.out.println(sauce.sauceType());
    }
}
```
```java
public class NYPizzaStoreTestDrive {
    public static void main(String[] args) {
        NYPizzaStore nyPizzaStore = new NYPizzaStore();
        nyPizzaStore.makePizza();
    }
}
```

???<3F><>??

```html
ThickCrustDough
MarinaraSauce
```

# ?? 5 ?? ??????

**1. ??????**

???????????????????????????????????

**2. ?????**

???????? Java ??????????<3F><>????????????<3F><>???????????????<3F><>?????????<3F><>?????????<3F><>????????????????<3F><>?????????????????<3F><>?????<3F><>????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/59aff6c1-8bc5-48e4-9e9c-082baeb2f274.jpg)

**3. ???????**

????????<3F><>???<3F><>???????????????????????????????????????????????????????????<3F><>??????????????????????????????????????????????????????????????? if(uniqueInstance == null) ??????<3F><>????????????? uniqueInstance ??<3F><>????????

```java
public class Singleton {

    private static Singleton uniqueInstance;

    private Singleton() {
    }

    public static Singleton getUniqueInstance() {
        if (uniqueInstance == null) {
            uniqueInstance = new Singleton();
        }
        return uniqueInstance;
    }
}
```

**4. ???????????????????**

?????? getUniqueInstance() ????????????????<3F><>????????????????????????????? uniqueInstance ???????<3F><>?????????????????????????????????????????????????????????????????

```java
    public static synchronized Singleton getUniqueInstance() {
        if (uniqueInstance == null) {
            uniqueInstance = new Singleton();
        }
        return uniqueInstance;
    }
```

**5. ????????????????????**

????????????????????????????

```java
private static Singleton uniqueInstance = new Singleton();
```

**6. ????????????????????**

????????????????????????? getUniqueInstance() ???????<3F><>?????????????????? uniqueInstance = new Singleton(); ?????????????<3F><>??????????????????<3F><>? uniqueInstance ???????????????????????????????????

```java
public class Singleton {

    private volatile static Singleton uniqueInstance;

    private Singleton() {
    }

    public static synchronized Singleton getUniqueInstance() {
        if (uniqueInstance == null) {
            synchronized (Singleton.class) {
                if (uniqueInstance == null) {
                    uniqueInstance = new Singleton();
                }
            }
        }
        return uniqueInstance;
    }
}
```

# ?? 6 ?? ??????

**1. ????????**

????????????????<3F><>??????????????????????????????????????????????<3F><>??????<3F><>????????????<3F><>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/7b8f0d8e-a4fa-4c9d-b9a0-3e6a11cb3e33.jpg)

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c3ca36b2-8459-4cf1-98b0-cc95a0e94f20.jpg)

**2. ??????**

??????????????????<3F><>????????????????????????

**3. ?????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1e09d75f-6268-4425-acf8-8ecd1b4a0ef3.jpg)

**4. ??????????**

Invoker ?????????????????????????????????????? execute() ??????Receiver ???????????????????????ConcreteCommand ?????????? Receiver ??????????????<3F><>? Receiver ??????????????? LightOnCommand ????? excute ??????<3F><>? Light ??????????Light ??????????? on() ??????????????Invoker ???? Client ??????????????????????? Invoker ?????????????????? Client ????????????<3F><>??????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/5ef94f62-98ce-464d-a646-842d9c72c8b8.jpg)

**5. ???????**

```java
public interface Command {
    public void execute();
}
```
```java
public class Light {

    public void on() {
        System.out.println("Light is on!");
    }

    public void off() {
        System.out.println("Light is off!");
    }
}
```
```java
public class LightOnCommand implements Command{
    Light light;

    public LightOnCommand(Light light) {
        this.light = light;
    }

    @Override
    public void execute() {
        light.on();
    }
}
```
```java
/**
 * ???????
 */
public class SimpleRemoteControl {
    Command slot;

    public SimpleRemoteControl() {

    }

    public void setCommand(Command command) {
        this.slot = command;
    }

    public void buttonWasPressed() {
        slot.execute();
    }

}
```
```java
public class RemoteLoader {
    public static void main(String[] args) {
        SimpleRemoteControl remote = new SimpleRemoteControl();
        Light light = new Light();
        LightOnCommand lightOnCommand = new LightOnCommand(light);
        remote.setCommand(lightOnCommand);
        remote.buttonWasPressed();
    }
}
```

???

```html
Light is on!
```

# ?? 7 ?? ???????????????

## 7.1 ????????

**1. ??????**

??????????????????????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8e8ba824-7a9e-4934-a212-e6a41dcc1602.jpg)

**2. ?????**

??????????????????????????????????????????????????????????????????????Adapter??????????????????Adaptee???????????????????<3F><>??????????????????????<3F><>?Adapter ??????? Target ?? Adaptee ?????????????? Adaptee ??????????????? Adapter ????????????? Target ?????????? Client ?????????????? Target ???????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/253bd869-ea48-4092-9aed-6906ccb2f3b0.jpg)

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a797959a-0ed5-475b-8d97-df157c672019.jpg)

**3. ????????**

??????Duck????????Turkey????Duck ?? quack() ???????? Turkey ??? gobble() ?????????????? Turkey ??? Duck ?? quack() ??????

**4. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1a511c76-bb6b-40ab-b8aa-39eeb619d673.jpg)

**5. ???????**

```java
public interface Duck {
    public void quack();
    public void fly();
}
```
```java
public interface Turkey {
    public void gobble();
    public void fly();
}
```
```java
public class WildTurkey implements Turkey{
    @Override
    public void gobble() {
        System.out.println("gobble!");
    }

    @Override
    public void fly() {
        System.out.println("fly!");
    }
}
```
```java
public class TurkeyAdapter implements Duck{
    Turkey turkey;

    public TurkeyAdapter(Turkey turkey) {
        this.turkey = turkey;
    }

    @Override
    public void quack() {
        turkey.gobble();
    }

    @Override
    public void fly() {
        turkey.fly();
    }
}
```
```java
public class DuckTestDrive {
    public static void main(String[] args) {
        Turkey turkey = new WildTurkey();
        Duck duck = new TurkeyAdapter(turkey);
        duck.quack();
        duck.fly();
    }
}
```

???<3F><>??
```html
gobble!
fly!
```

## 7.2 ?????

**1. ??????**

???????????????????????????<3F><>??????????????????????????????????????<3F><>?

**2. ?????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/78f2314e-2643-41df-8f3d-b7e28294094b.jpg)

**3. ????????**

???????????????????????<3F><>???????????????????<3F><>???????????<3F><>????????<3F><>???????????????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/106f5585-b2e7-4718-be5d-3b322d1ef42a.jpg)

**4. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/25387681-89f8-4365-a2fa-83b86449ee84.jpg)

**5. ??????**

**?????????**????????????????????????????????????????????????????????????

# ?? 8 ?? ??<3F><>????

**1. ??????**

??????????<3F><>??????????????????<3F><>?????????????<3F><>?

??<3F><>????????????????????????????????????????<3F><>??<3F><>???<3F><>

**2. ?????**

??<3F><>?? templateMethod() ?????????????????? primitiveOperation1() ?? primitiveOperation2() ??????<3F><>????? primitiveOperation1() ?? primitiveOperation2() ???????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ed62f400-192c-4185-899b-187958201f0c.jpg)

**3. ????????**

?<3F><>????<3F><>?????????????????<3F><>??????<3F><>??????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/d8f873fc-00bc-41ee-a87c-c1b4c0172844.png)

**4. ??????????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/aa20c123-b6b5-432a-83d3-45dc39172192.jpg)

**5. ??????**

**?????????**??????????<3F><>????????????????????<3F><>??????????????????????????????????????????????????????????????????????????????<3F><>?????????????<3F><>???????????????????????

**6. ????**

?????hock?????<3F><>????????????<3F><>??<3F><>????????????????????????????????????????<3F><>?? templteMethod() ?<3F><>??????????????????????????????????????

**7. ???????**

```java
public abstract class CaffeineBeverage {

    final void prepareRecipe(){
        boilWater();
        brew();
        pourInCup();
        addCondiments();
    }

    abstract void brew();

    abstract void addCondiments();

    void boilWater(){
        System.out.println("boilWater");
    }

    void pourInCup(){
        System.out.println("pourInCup");
    }
}
```
```java
public class Coffee extends CaffeineBeverage{
    @Override
    void brew() {
        System.out.println("Coffee.brew");
    }

    @Override
    void addCondiments() {
        System.out.println("Coffee.addCondiments");
    }
}
```
```java
public class Tea extends CaffeineBeverage{
    @Override
    void brew() {
        System.out.println("Tea.brew");
    }

    @Override
    void addCondiments() {
        System.out.println("Tea.addCondiments");
    }
}
```
```java
public class CaffeineBeverageTestDrive {
    public static void main(String[] args) {
        CaffeineBeverage caffeineBeverage = new Coffee();
        caffeineBeverage.prepareRecipe();
        System.out.println("-----------");
        caffeineBeverage = new Tea();
        caffeineBeverage.prepareRecipe();
    }
}
```

???<3F><>??

```html
boilWater
Coffee.brew
pourInCup
Coffee.addCondiments
-----------
boilWater
Tea.brew
pourInCup
Tea.addCondiments
```

# ?? 9 ?? ?????????????

## 9.1 ????????

**1. ??????**

?????????????????????<3F><>????????????????????????????????

**2. ?????**

?????????????????????????????????????????????????????????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/439deca7-fed0-4c89-87e5-7088d10f1fdb.jpg)

**3. ???????**

```java
public class Aggregate {

    private int[] items;

    public Aggregate() {
        items = new int[10];
        for (int i = 0; i < items.length; i++) {
            items[i] = i;
        }
    }

    public Iterator createIterator() {
        return new ConcreteIterator(items);
    }

}
```
```java
public interface Iterator {
    boolean hasNext();
    int next();
}
```
```java
public class ConcreteIterator implements Iterator {

    private int[] items;
    private int position = 0;

    public ConcreteIterator(int[] items) {
        this.items = items;
    }

    @Override
    public boolean hasNext() {
        return position < items.length;
    }

    @Override
    public int next() {
        return items[position++];
    }
}
```
```java
public class Client {
    public static void main(String[] args) {
        Aggregate aggregate = new Aggregate();
        Iterator iterator = aggregate.createIterator();
        while(iterator.hasNext()){
            System.out.println(iterator.next());
        }
    }
}
```
???<3F><>??
```html
0
1
2
3
4
5
6
7
8
9
```

## 9.2 Java ??????????

**1. ?????**

Java ????????? Iterator ????????? Java ??????????????????? Iterable ????????????? iterator() ??????????? Iterator ??????? Java ??????????????????????????? foreach ????????????????<3F><>????????

**2. ???????**

```java
import java.util.Iterator;

public class Aggregate implements Iterable<Integer>{

    private int[] items;

    public Aggregate() {
        items = new int[10];
        for (int i = 0; i < items.length; i++) {
            items[i] = i;
        }
    }

    @Override
    public Iterator<Integer> iterator() {
        return new ConcreteIterator(items);
    }
}
```
```java
import java.util.Iterator;

public class ConcreteIterator implements Iterator<Integer> {

    private int[] items;
    private int position = 0;

    public ConcreteIterator(int[] items) {
        this.items = items;
    }

    @Override
    public boolean hasNext() {
        return position < items.length;
    }

    @Override
    public Integer next() {
        return items[position++];
    }
}
```
```java
public class Client {
    public static void main(String[] args) {
        Aggregate aggregate = new Aggregate();
        for (int item : aggregate) {
            System.out.println(item);
        }
    }
}
```

## 9.3 ?????

**1. ??????**

????????????????????????

**2. ??????**

???????????????<3F><>???????????? / ???????<3F><>???

??????????????????????????????????????

**3. ?????**

????????Composite???????????????Component???????????????<3F><>?????<3F><>????<3F><>???????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/f99c019e-7e91-4c2e-b94d-b031c402dcb5.jpg)

**4. ???????**

```java
public abstract class Component {
    protected String name;

    public Component(String name) {
        this.name = name;
    }

    abstract public void addChild(Component component);

    public void print() {
        print(0);
    }

    abstract protected void print(int level);
}
```
```java
public class Leaf extends Component {
    public Leaf(String name) {
        super(name);
    }

    @Override
    public void addChild(Component component) {
        throw new UnsupportedOperationException(); // ???????????????????? , ??????????????????????????
    }

    @Override
    protected void print(int level) {
        for (int i = 0; i < level; i++) {
            System.out.print("--");
        }
        System.out.println("left:" + name);
    }
}
```
```java
import java.util.ArrayList;
import java.util.List;

public class Composite extends Component {

    private List<Component> childs;

    public Composite(String name) {
        super(name);
        childs = new ArrayList<>();
    }

    @Override
    public void addChild(Component component) {
        childs.add(component);
    }

    @Override
    protected void print(int level) {
        for (int i = 0; i < level; i++) {
            System.out.print("--");
        }
        System.out.println("Composite:" + name);
        for (Component component : childs) {
            component.print(level + 1);
        }
    }
}
```
```java
public class Client {
    public static void main(String[] args) {
        Composite root = new Composite("root");
        Component node1 = new Leaf("1");
        Component node2 = new Composite("2");
        Component node3 = new Leaf("3");
        root.addChild(node1);
        root.addChild(node2);
        root.addChild(node3);
        Component node21 = new Leaf("21");
        Component node22 = new Composite("22");
        node2.addChild(node21);
        node2.addChild(node22);
        Component node221 = new Leaf("221");
        node22.addChild(node221);
        root.print();
    }
}
```
???<3F><>??

```html
Composite:root
--left:1
--Composite:2
----left:21
----Composite:22
------left:221
--left:3
```

# ?? 10 ?? ????

**1. ??????**

?????????????????????????????????????????????????????

???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????<3F><>????????????????????????????????????????????????<3F><>???????????????????????<3F><>???????????????????????????????????????????????????????????????????????

**2. ?????**

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c28fd93a-0d55-4a19-810f-72652feee00d.jpg)

**3. ????????**

?????????<3F><>????????????????????<3F><>???????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/f7d880c9-740a-4a16-ac6d-be502281b4b2.jpg)

**4. ?????????**

???????????????????????<3F><>?<3F><>??????????????????????<3F><>????????????????????????????????????????<3F><>???????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/62ebbb63-8fd7-4488-a866-76a9dc911662.png)

**5. ???????????????**

??????????????????<3F><>???????????????????<3F><>???????????????????????????????????<3F><>????????


**6. ???????**

```java
public interface State {
    /**
     * ???25 ???
     */
    void insertQuarter();

    /**
     * ???25 ???
     */
    void ejectQuarter();

    /**
     * ???????
     */
    void turnCrank();

    /**
     * ???????
     */
    void dispense();
}
```
```java
public class HasQuarterState implements State{
    private GumballMachine gumballMachine;

    public HasQuarterState(GumballMachine gumballMachine){
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("You can't insert another quarter");
    }

    @Override
    public void ejectQuarter() {
        System.out.println("Quarter returned");
        gumballMachine.setState(gumballMachine.getNoQuarterState());
    }

    @Override
    public void turnCrank() {
        System.out.println("You turned...");
        gumballMachine.setState(gumballMachine.getSoldState());
    }

    @Override
    public void dispense() {
        System.out.println("No gumball dispensed");
    }
}
```
```java
public class NoQuarterState implements State {
    GumballMachine gumballMachine;

    public NoQuarterState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("You insert a quarter");
        gumballMachine.setState(gumballMachine.getHasQuarterState());
    }

    @Override
    public void ejectQuarter() {
        System.out.println("You haven't insert a quarter");
    }

    @Override
    public void turnCrank() {
        System.out.println("You turned, but there's no quarter");
    }

    @Override
    public void dispense() {
        System.out.println("You need to pay first");
    }
}
```
```java
public class SoldOutState implements State {

    GumballMachine gumballMachine;

    public SoldOutState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("You can't insert a quarter, the machine is sold out");
    }

    @Override
    public void ejectQuarter() {
        System.out.println("You can't eject, you haven't inserted a quarter yet");
    }

    @Override
    public void turnCrank() {
        System.out.println("You turned, but there are no gumballs");
    }

    @Override
    public void dispense() {
        System.out.println("No gumball dispensed");
    }
}
```
```java
public class SoldState implements State {
    GumballMachine gumballMachine;

    public SoldState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("Please wait, we're already giving you a gumball");
    }

    @Override
    public void ejectQuarter() {
        System.out.println("Sorry, you already turned the crank");
    }

    @Override
    public void turnCrank() {
        System.out.println("Turning twice doesn't get you another gumball!");
    }

    @Override
    public void dispense() {
        gumballMachine.releaseBall();
        if(gumballMachine.getCount()>0){
            gumballMachine.setState(gumballMachine.getNoQuarterState());
        } else{
            System.out.println("Oops, out of gumballs");
            gumballMachine.setState(gumballMachine.getSoldOutState());
        }
    }
}
```
```java
public class GumballMachine {
    private State soldOutState;
    private State noQuarterState;
    private State hasQuarterState;
    private State soldState;

    private State state;
    private int count = 0;

    public GumballMachine(int numberGumballs) {
        count = numberGumballs;
        soldOutState = new SoldOutState(this);
        noQuarterState = new NoQuarterState(this);
        hasQuarterState = new HasQuarterState(this);
        soldState = new SoldState(this);

        if (numberGumballs > 0) {
            state = noQuarterState;
        } else {
            state = soldOutState;
        }
    }

    public void insertQuarter() {
        state.insertQuarter();
    }

    public void ejectQuarter() {
        state.ejectQuarter();
    }

    public void turnCrank() {
        state.turnCrank();
        state.dispense();
    }

    public void setState(State state) {
        this.state = state;
    }

    public void releaseBall() {
        System.out.println("A gumball comes rolling out the slot...");
        if (count != 0) {
            count -= 1;
        }
    }

    public State getSoldOutState() {
        return soldOutState;
    }

    public State getNoQuarterState() {
        return noQuarterState;
    }

    public State getHasQuarterState() {
        return hasQuarterState;
    }

    public State getSoldState() {
        return soldState;
    }

    public int getCount() {
        return count;
    }
}
```
```java
public class GumballMachineTestDrive {
    public static void main(String[] args) {
        GumballMachine gumballMachine = new GumballMachine(5);

        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();

        gumballMachine.insertQuarter();
        gumballMachine.ejectQuarter();
        gumballMachine.turnCrank();

        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();
        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();
        gumballMachine.ejectQuarter();

        gumballMachine.insertQuarter();
        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();
        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();
        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();
    }
}
```
???<3F><>??
```html
You insert a quarter
You turned...
A gumball comes rolling out the slot...
You insert a quarter
Quarter returned
You turned, but there's no quarter
You need to pay first
You insert a quarter
You turned...
A gumball comes rolling out the slot...
You insert a quarter
You turned...
A gumball comes rolling out the slot...
You haven't insert a quarter
You insert a quarter
You can't insert another quarter
You turned...
A gumball comes rolling out the slot...
You insert a quarter
You turned...
A gumball comes rolling out the slot...
Oops, out of gumballs
You can't insert a quarter, the machine is sold out
You turned, but there are no gumballs
No gumball dispensed
```

# ?? 11 ?? ?????? // TODO

# ?? 12 ?? ??????

## 12.1 MVC

### 12.1.1 ??? MVC

???????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/4f67611d-492f-4958-9fa0-4948010e345f.jpg)

### 12.1.2 Web ?<3F><>? MVC

????????<3F><>????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1dd56e61-2970-4d27-97c2-6e81cee86978.jpg)

# ?? 13 ?? ?????????

???<3F><>??? **??** ??????? **????** ????? **???????**??

?????????????????????????????????????????????????????????????????????????????????????

???????????????????????????????????????????<3F><>??????<3F><>?????????

??????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/524a237c-ffd7-426f-99c2-929a6bf4c847.jpg)

# ?? 14 ?? ?????? // TODO