依赖解析器
<?php require 'lib.php'; class App { // 创建自动解析函数 function build($class){ $reflect = new ReflectionClass($class); if(!$reflect->isInstantiable()){ throw new Exception('cannot be instantiated'); } $constructor = $reflect->getConstructor(); if(is_null($constructor)){ return new $class; } // 获取实例化时候的各个参数 $parameters = $constructor->getParameters(); $dependencies = $this->getDependencies($parameters); return $reflect->newInstanceArgs($dependencies); } // public function getDependencies($params){ $dependencies = []; foreach($params as $param){ $dependency = $param->getClass(); if(is_null($dependency)){ // 处理非class类型的函数 $dependencies[] = $this->resolveNonClass($param); }else{ // 处理class类型的函数 $dependencies[] = $this->build($dependency->name); } } return $dependencies; } // 解析没有参数的 public function resolveNonClass($param){ if($param->isDefaultValueAvailable()){ return $param->getDefaultValue(); } throw new Exception('no default value, no idea what to do'); } } $class = 'lib\A'; $object = (new App)->build($class); print_r($object);用于测试依赖解析的类，文件名./lib.php
<?php namespace lib; class A{ protected $b; protected $c; public function __construct(B $b, C $c){ $this->b = $b; $this->c = $c; } } class B{ protected $c; public function __construct(C $c){ $this->c = $c; } } class C{ }执行依赖解析器后的输出结果是：
lib\A Object ( [b:protected] => lib\B Object ( [c:protected] => lib\C Object ( ) ) [c:protected] => lib\C Object ( ) )