Design Patterns in Luster

Design Patterns

© 2014 Luster

Me

Reference啓

Object Oriented

Basic

⽤用情境，學設計模式

Class Diagram

MallardDuck

display() { }swim()quack()

RedheadDuck

display() { }swim()quack()

Class Diagram

MallardDuck

display() { }swim()quack()

RedheadDuck

display() { }swim()quack()

Duck

Class Diagram

MallardDuck

display() { } display() { }

RedheadDuck

Duck

swim()quack()

Class Diagram

MallardDuck

display() { } display() { }

RedheadDuck

Duck

swim()quack()

display()

Class Diagram

MallardDuck

display() { } display() { }

RedheadDuck

Duck

swim()quack()

display()

模擬鴨子，全 改版

讓鴨子飛新

“

”

MallardDuckdisplay() { }

Duckquack()

display()swim()

RedheadDuckdisplay() { }

Class Diagram

MallardDuckdisplay() { }

Duckquack()

display()swim()

RedheadDuckdisplay() { }

fly()

Jason’s Class Diagram

公測那一天

黃色塑膠鴨竟然也會飛了－ －|||

What’s happened ?

Duckquack()

display()swim()

fly()RubberDuck

quack() { 吱吱叫; }@Override

display() { }

Duckquack()

display()swim()

fly()

RubberDuck

display() { }

quack() { 吱吱叫; }@Override

“

”

Jason’s Class Diagram II

Duckquack()

display()swim()

fly()

RubberDuck

quack() { 吱吱叫; }@Override

display() { }

fly() { // Do nothing! }@Override

“

”

FireDuck

quack() { // Do nothing! }@Override

display() { }

fly() { // Do nothing! }@Override

swim() { // Do nothing! }@Override

A.

B.

C.

D.

E.

F.

“ ”

“ ”

“ ”

而且又繼續用繼承的方式，那我豈不是要

逐鴨審查而且又繼續用繼承的方式，那我豈不是要

“

”

Duck

display()swim()Flyable

fly()

Quackablequack()

MallardDuck RedheadDuck RubberDuck

“

”

Duck

display()swim()Flyable

fly()

Quackablequack()

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

“

”

Duck

display()swim()Flyable

fly()

Quackablequack()

MallardDuck

fly()display()

RedheadDuck

fly()display()

RubberDuckdisplay()

“

”

Duck

display()swim()Flyable

fly()

Quackablequack()

MallardDuck

fly()display()

quack()

RedheadDuck

fly()display()

quack()

RubberDuckdisplay()quack()

“

”

Duck

display()swim()Flyable

fly()

Quackablequack()

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

“”

fly()quack()

fly()quack()

quack()

設計守則 Design Principle

1

1

2

Program to an !interface,!

not an implementation.

2

Example

Soldierattack()

Sniperattack() {!! snipe();!}snipe()

Stormtrooperattack() {!! shoot();!}shoot()

Program to an implement

Sniper soldier = new Sniper(); soldier.attack();

Program to an interface

Sniper soldier = new Sniper(); soldier.attack();

Soldier soldier = new Sniper(); soldier.attack();

Sniper soldier = new Sniper(); soldier.attack();

Soldier soldier = new Sniper(); soldier.attack();

Soldier soldier = getSoldier(); soldier.attack();

Program to an interface

QuackBehaviorquack()

<< interface >>

FlyBehaviorfly()

<< interface >>

QuackBehaviorquack()

<< interface >>

FlyBehaviorfly()

<< interface >>

Squeakquack() { 吱吱叫; }

MuteQuackquack() { 不會叫; }

Quackquack() { 呱呱叫; }

FlyWithWingsfly() { ⽤用翅膀飛; }

FlyWithRocketfly() { ⽤用⽕火箭飛; }

FlyNoWayfly() { 不會飛; }

Duck

display()swim()

Duck

display()swim()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; }

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { quackBehavior.quack(); } public void performFly() {…} }

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { ! } public void performFly() {…} }

quackBehavior.quack();

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { quackBehavior.quack(); } public void performFly() {…} }

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { quackBehavior.quack(); } public void performFly() {…} }

public class MallardDuck extends Duck { ! public MallardDuck() { quackBehavior = new Quack(); flyBehavior = new FlyWithNoWings(); } ! public void display() {…} }

public class DuckSimulator { ! public static void main(String[] args) { Duck mallard = new MallardDuck(); mallard.performQuack(); } }

public class DuckSimulator { ! public static void main(String[] args) { Duck mallard = new MallardDuck(); mallard.performQuack(); } }

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { quackBehavior.quack(); } public void performFly() {…} !}

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { quackBehavior.quack(); } public void performFly() {…} !}

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

setQuackBehavior()setFlyBehavior()

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

setQuackBehavior()setFlyBehavior()

public abstract class Duck { QuackBehavior quackBehavior; FlyBehavior flyBehavior; ! public void performQuack() { quackBehavior.quack(); } public void performFly() {…} ! public void setQuackBehavior( QuackBehavior behavior) { this.quackBehavior = behavior; } public void setFlyBehavior… }

public class DuckSimulator { ! public static void main(String[] args) { Duck mallard = new MallardDuck(); mallard.performQuack(); mallard.setQuackBehavior(new Squeak()); mallard.performQuack(); } }

public class DuckSimulator { ! public static void main(String[] args) { Duck mallard = new MallardDuck(); mallard.performQuack(); mallard.setQuackBehavior(new Squeak()); mallard.performQuack(); } }

public class DuckSimulator { ! public static void main(String[] args) { Duck mallard = new MallardDuck(); mallard.performQuack(); mallard.setQuackBehavior(new Squeak()); mallard.performQuack(); } }

QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

Duck QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

MallardDuck

display()swim()

RedheadDuck

display()swim()

RubberDuck

display()swim()

QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

Duck

display()swim()

Duck

display()swim()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

setQuackBehavior()setFlyBehavior()

QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

Duck

display()swim()

performQuack()performFly()

QuackBehavior quackBehaviorFlyBehavior flyBehavior

setQuackBehavior()setFlyBehavior()

QuackBehaviorquack()

<< interface >>

Quackquack() { 呱; }

MuteQuackquack() {}

Squeakquack() { 吱; }

FlyBehaviorfly()

<< interface >>

FlyWithWingsfly() { 拍翅膀; }

FlyNoWayfly() {}

FlyWithRocketfly() { 噴射; }

MallardDuckdisplay()

RedheadDuckdisplay()

RubberDuckdisplay()

3

策略模式 Strategy

Strategy

Strategy

Strategy

Strategy

為什麼我們需要學設計模式

Z > B

Z > B

Jas

!

結論

變 化設 計

ThanksJason Chung