laravel 依赖注入

<?php interface  Animal{

     public  function attack();     public  function talk();

 }

class People implements Animal{    public  $month;    public  $hand;    public  function __construct(Mouth $mouth,Hand $hand)    {        $this->month = $mouth;        $this->hand  = $hand;

    }

    public  function attack()    {        $this->hand->scrap();    }

    public  function talk()    {       $this->month->say();    }

}

class  Mouth{    public  function say(){        echo "咿咿呀呀";    }}class  Hand{    public  $finger;    public  function __construct(Finger $finger)    {        $this->finger = $finger;    }

    public  function scrap(){        echo ‘仍玩具‘;    }

    public  function otherFunction(){        $this->finger->eatFinger();    }}

class Finger{     public  function eatFinger(){         echo "吃手指";     }}

class Container{    /**     *  容器绑定，用来装提供的实例或者 提供实例的回调函数     * @var array     */    public $building = [];

    /**     * 注册一个绑定到容器     */    public function bind($abstract, $concrete = null, $shared = false){    if(is_null($concrete)){        $concrete = $abstract;    }

    if(!$concrete instanceOf Closure){        $concrete = $this->getClosure($abstract, $concrete);    }

    $this->building[$abstract] =  compact("concrete", "shared");}

    //注册一个共享的绑定 单例    public function singleton($abstract, $concrete, $shared = true){    $this->bind($abstract, $concrete, $shared);}

    /**     * 默认生成实例的回调闭包     *     * @param $abstract     * @param $concrete     * @return Closure     */    public function getClosure($abstract, $concrete){    return function($c) use($abstract, $concrete){        $method = ($abstract == $concrete)? ‘build‘ : ‘make‘;        return $c->$method($concrete);    };}

    /**     * 生成实例     */    public function make($abstract){    $concrete = $this->getConcrete($abstract);

    if($this->isBuildable($concrete, $abstract)){        $object = $this->build($concrete);    }else{        $object = $this->make($concrete);    }

    return $object;}

    /**     * 获取绑定的回调函数     */    public function getConcrete($abstract){

    if(! isset($this->building[$abstract])){        return $abstract;    }

    return $this->building[$abstract][‘concrete‘];}

    /**     * 判断 是否 可以创建服务实体     */    public function isBuildable($concrete, $abstract){

    return $concrete === $abstract || $concrete instanceof Closure;    }

    /**     * 根据实例具体名称实例具体对象     */    public function build($concrete){

    if($concrete instanceof Closure){        return $concrete($this);    }

    //创建反射对象    $reflector = new ReflectionClass($concrete);//通过反射获取类名

    if( ! $reflector->isInstantiable()){        //抛出异常        throw new \Exception(‘无法实例化‘);    }

    $constructor = $reflector->getConstructor();//获取构造函数    if(is_null($constructor)){        return new $concrete;    }

    $dependencies = $constructor->getParameters();//获取构造函数参数    $instance = $this->getDependencies($dependencies);    return $reflector->newInstanceArgs($instance);//将参数注入到对象中

}

    //通过反射解决参数依赖    public function getDependencies(array $dependencies){    $results = [];    foreach( $dependencies as $dependency ){        $results[] = is_null($dependency->getClass())            ?$this->resolvedNonClass($dependency)            :$this->resolvedClass($dependency);    }

    return $results;}

    //解决一个没有类型提示依赖    public function resolvedNonClass(ReflectionParameter $parameter)    {    if($parameter->isDefaultValueAvailable()){        return $parameter->getDefaultValue();    }    throw new \Exception(‘出错‘);

    }

    //通过容器解决依赖    public function resolvedClass(ReflectionParameter $parameter)    {         return $this->make($parameter->getClass()->name);

    }

}//实例化容器类$container =  new Container();$container->bind(‘Animal‘,‘People‘);//将需要创建对象的类放到容器中$people  = $container->make(‘Animal‘);//创建对象$people->attack();//调用方法$people->talk();

原文地址：https://www.cnblogs.com/paulversion/p/11703522.html