创建型设计模式

2022-08-23 703 words 2 minutes

Contents

概念

简单来说就是用来创建对象的设计模式，主要的特点是将对象的创建于使用分离。

简单工厂

定义一个类（工厂类）来负责创建其他类。根据不同的参数返回不同类的实例。

interface Computer
{
    public function describe();
}

class Hasee implements Computer
{
    public function describe()
    {
        print_r('神舟电脑');
    }
}

class Macbook implements Computer
{
    public function describe()
    {
        print_r('苹果电脑');
    }
}

class Fatory
{
    public function create($type)
    {
        if ($type === 'hasee') {
            return new Hasee();
        } else if ($type === 'hasee') {
            return new Macbook();
        }
        return null;
    }
}

工厂方法

interface Computer
{
    public function describe();
}

class Hasee implements Computer
{
    public function describe()
    {
        print_r('神舟电脑');
    }
}

class Macbook implements Computer
{
    public function describe()
    {
        print_r('苹果电脑');
    }
}

interface Factory
{
    public function create();
}

class HaseeFactory implements Factory
{
    public function create()
    {
        return new Hasee();
    }
}

class MacbookFactory implements Factory
{
    public function create()
    {
        return new Macbook();
    }
}

抽象工厂

在工产方法中一个工产方法是生成一个对象，抽象工厂则是生产一类的对象

interface Computer
{
    public function describe();
}

class Hasee implements Computer
{
    public function describe()
    {
        print_r('神舟电脑');
    }
}

class Lenovo implements Computer
{
    public function describe()
    {
        print_r('联想电脑');
    }
}

class Macbook implements Computer
{
    public function describe()
    {
        print_r('苹果电脑');
    }
}



interface Factory
{
    public function create($type);
}

class MacFactory implements Factory
{
    public function create($type)
    {
        if ($type === 'mac') {
            return new Macbook();
        }
        return null;
    }
}

class WindowFactory implements Factory
{
    public function create($type)
    {
        if ($type === 'lenovo') {
            return new Lenovo();
        } else if ($type === 'hasee') {
            return new Hasee();
        }
        return null;
    }
}

单例

class Single
{
    private static Single $instance;
    final private function __construct()
    {
        
    }

    final private function __clone()
    {
        
    }
    public static function getInstance()
    {
        if (!self::$instance) {
            self::$instance = new self();
        }
        return self::instance;
    }
}

建造者

它将一个复杂对象的创建于它的表示分离，可以通过设置不同的参数来构建对象。

class Builder
{
    public $color;
    public $cpu;
    public function setColor($color)
    {
        $this->color = $color;
        return $this;
    }
    public function setCpu($cpu)
    {
        $this->cpu = $cpu;
        return $this;
    }

    public function build()
    {
        return new Computer($this);
    }
}

class Computer
{
    private $builder;
    public function __construct(Builder $builder)
    {
        $this->builder = $builder;
    }
}

$builder = new Builder();
$computer = $builder->setColor('red')->setCpu('i7')->build();

原型模式

通过复制原型来创建对象

class Hasee implements Computer
{
    public function describe()
    {
        print_r('神舟电脑');
    }
}

$hasee = new Hasee();
$haseeCopy = clone $hasee;