PHP设计模式—享元模式

/**
 * 抽象类
 * Class Flyweight
 */
abstract class Flyweight
{
    protected $name;
 
    public function __construct($name)
    {
        $this->name = $name;
    }
 
 
    abstract public function show($content);
}
 
 
/**
 * 共享的具体类
 * Class ConcreteFlyweight
 */
class ConcreteFlyweight extends Flyweight
{
 
    /**
     * @param $content
     */
    public function show($content)
    {
        // TODO: Implement show() method.
        echo "共享的享元：{$this->name} {$content} <br>";
    }
 
}
 
 
/**
 * 不共享的具体类
 * Class UnsharedConcreteFlyweight
 */
class UnsharedConcreteFlyweight extends Flyweight
{
 
    /**
     * @param $content
     */
    public function show($content)
    {
        // TODO: Implement show() method.
        echo "不共享的享元：{$this->name} {$content} <br>";
    }
 
}
 
 
/**
 * 享元工厂
 * Class FlyweightFactory
 */
class FlyweightFactory
{
 
    /**
     * @var array
     */
    private $flyweights = [];
 
 
    /**
     * @param $name
     * @return mixed
     */
    public function getFlyweight($name)
    {
        if (!isset($this->flyweights[$name])) {
            $this->flyweights[$name] = new ConcreteFlyweight($name);
        }
        return $this->flyweights[$name];
    }
 
}
 
 
##客户端代码
// 创建享元工厂
$flyweightFactory = new FlyweightFactory();
 
// 共享的享元
$flyweight = $flyweightFactory->getFlyweight('state A');
$flyweight->show('other state A');
$flyweight = $flyweightFactory->getFlyweight('state B');
$flyweight->show('other state B');
 
// 不共享的对象，单独调用
$uflyweight = new UnsharedConcreteFlyweight('state A');
$uflyweight->show('state A');
 
 
##测试结果
共享的享元：state A other state A
共享的享元：state B other state B
不共享的享元：state A state A