设计模式——责任链模式

说明

示例

下面看下责任链模式的代码实现

interface Handler{
    public function operation();
}

abstract class AbstractHandler{
    private ?Handler $handler=null;

    public function getHandler(): ?Handler{
        return $this->handler;
    }

    public function setHandler(Handler $handler){
        $this->handler = $handler;
    }
}

class MyHandler extends AbstractHandler implements Handler{
    private string $name;

    public function __construct(string $name){
        $this->name = $name;
    }

    public function operation(){
        echo $this->name . ' deal!' . PHP_EOL;
        if (($handler=$this->getHandler()) != null){
            $handler->operation();
        }
    }
}


// 调用
$h1 = new MyHandler("h1");
$h2 = new MyHandler("h2");
$h3 = new MyHandler("h3");

$h1->setHandler($h2);
$h2->setHandler($h3);

$h1->operation();
/**
 * output:
 * h1 deal! h2 deal! h3 deal!
 * 
 */

总结