PHP结构型模式之享元模式详解

<?php
// 享元接口
interface Flyweight
{
    public function operation();
}
// 具体享元类
class ConcreteFlyweight implements Flyweight
{
    private $state;
    public function __construct($state)
    {
        $this->state = $state;
    }
    public function operation()
    {
        echo "ConcreteFlyweight with state {$this->state} is operated.\n";
    }
}
// 享元工厂类
class FlyweightFactory
{
    private $flyweights = [];
    public function getFlyweight($state)
    {
        if (!isset($this->flyweights[$state])) {
            $this->flyweights[$state] = new ConcreteFlyweight($state);
        }
        return $this->flyweights[$state];
    }
}
// 客户端代码
$factory = new FlyweightFactory();
$flyweight1 = $factory->getFlyweight("state1");
$flyweight1->operation();
$flyweight2 = $factory->getFlyweight("state2");
$flyweight2->operation();
$flyweight3 = $factory->getFlyweight("state1");
$flyweight3->operation();
 

<?php
$factory = new FlyweightFactory();
$flyweight1 = $factory->getFlyweight("state1");
$flyweight1->operation();
$flyweight2 = $factory->getFlyweight("state2");
$flyweight2->operation();
$flyweight3 = $factory->getFlyweight("state1");
$flyweight3->operation();