Detailed explanation of PHP reflection mechanism

<?phpclass Student{

    const NORMAL = 1;    const FORBIDDEN = 2;    /**

     * 用户ID

     * @var 类型

     */

    public $id;    /**

     * 获取id

     * @return int

     */

    public function getId()

    {

        return $this->id;

    }    public function setId($id = 1)

    {

        $this->id = $id;

    }

}$ref = new ReflectionClass(&#39;Student&#39;);$doc = $ref->getDocComment();echo $ref->getName() . &#39;:&#39; . getComment($ref) , "<br/>";echo "属性列表：<br/>";

printf("%-15s%-10s%-40s<br/>", &#39;Name&#39;, &#39;Access&#39;, &#39;Comment&#39;);$attr = $ref->getProperties();foreach ($attr as $row) {

    printf("%-15s%-10s%-40s<br/>", $row->getName(), getAccess($row), getComment($row));

}echo "常量列表：<br/>";

printf("%-15s%-10s<br/>", &#39;Name&#39;, &#39;Value&#39;);$const = $ref->getConstants();foreach ($const as $key => $val) {

    printf("%-15s%-10s<br/>", $key, $val);

}echo "<br/><br/>";echo "方法列表<br/>";

printf("%-15s%-10s%-30s%-40s<br/>", &#39;Name&#39;, &#39;Access&#39;, &#39;Params&#39;, &#39;Comment&#39;);$methods = $ref->getMethods();foreach ($methods as $row) {

    printf("%-15s%-10s%-30s%-40s<br/>", $row->getName(), getAccess($row), getParams($row), getComment($row));

}// 获取权限function getAccess($method){

    if ($method->isPublic()) {        return 'Public';

    }    if ($method->isProtected()) {        return 'Protected';

    }    if ($method->isPrivate()) {        return 'Private';

    }

}// 获取方法参数信息function getParams($method){

    $str = '';    $parameters = $method->getParameters();    foreach ($parameters as $row) {        $str .= $row->getName() . ',';        if ($row->isDefaultValueAvailable()) {            $str .= "Default: {$row->getDefaultValue()}";

        }

    }    return $str ? $str : '';

}// 获取注释function getComment($var){

    $comment = $var->getDocComment();    // 简单的获取了第一行的信息，这里可以自行扩展

    preg_match('/\* (.*) *?/', $comment, $res);    return isset($res[1]) ? $res[1] : '';

}

Student:

属性列表：

Name Access Comment

id Public 用户ID

常量列表：

Name Value

NORMAL 1 FORBIDDEN 2 方法列表

Name Access Params Comment

getId Public 获取id

setId Public id,Default: 1

$class = new ReflectionClass(ucfirst($controller) . 'Controller');$controller = $class->newInstance();if ($class->hasMethod($method)) {    $method = $class->getMethod($method);    $method->invokeArgs($controller, $arguments);

} else {

    throw new Exception("{$controller} controller method {$method} not exists!");

}

<?phpclass Calc{

    public function plus($a, $b)

    {

        return $a + $b;

    }    public function minus($a, $b)

    {

        return $a - $b;

    }

}function testEqual($method, $assert, $data){

    $arr = explode('@', $method);    $class = $arr[0];    $method = $arr[1];    $ref = new ReflectionClass($class);    if ($ref->hasMethod($method)) {        $method = $ref->getMethod($method);        $res = $method->invokeArgs(new $class, $data);        if($res === $assert){            echo "测试结果正确";

        };

    }

}

testEqual(&#39;Calc@plus&#39;, 3, [1, 2]);echo  "<br/>";

testEqual('Calc@minus', -1, [1, 2]);

<?phpfunction title($title, $name){

    return sprintf("%s. %s\r\n", $title, $name);

}$function = new ReflectionFunction('title');echo $function->invokeArgs(array('Dr', 'Phil'));?>

<?phpclass DI{

    protected static $data = [];    public function __set($k, $v)

    {

        self::$data[$k] = $v;

    }    public function __get($k)

    {

        return $this->bulid(self::$data[$k]);

    }    // 获取实例

    public function bulid($className)

    {

        // 如果是匿名函数，直接执行，并返回结果

        if ($className instanceof Closure) {            return $className($this);

        }        // 已经是实例化对象的话，直接返回

        if(is_object($className)) {            return $className;

        }        // 如果是类的话，使用反射加载

        $ref = new ReflectionClass($className);        // 监测类是否可实例化

        if (!$ref->isInstantiable()) {            throw new Exception('class' . $className . ' not find');

        }        // 获取构造函数

        $construtor = $ref->getConstructor();        // 无构造函数，直接实例化返回

        if (is_null($construtor)) {            return new $className;

        }        // 获取构造函数参数

        $params = $construtor->getParameters();        // 解析构造函数

        $dependencies = $this->getDependecies($params);        // 创建新实例

        return $ref->newInstanceArgs($dependencies);

    }    // 分析参数，如果参数中出现依赖类，递归实例化

    public function getDependecies($params)

    {

        $data = [];        foreach($params as $param)

        {            $tmp = $param->getClass();            if (is_null($tmp)) {                $data[] = $this->setDefault($param);

            } else {                $data[] = $this->bulid($tmp->name);

            }

        }        return $data;

    }    // 设置默认值

    public function setDefault($param)

    {

        if ($param->isDefaultValueAvailable()) {            return $param->getDefaultValue();

        }        throw new Exception('no default value!');

    }

}class Demo{

    public function __construct(Calc $calc)

    {

        echo $calc->plus(1, 2);

    }

}class Calc{

    public function plus($a, $b)

    {

        return $a + $b;

    }    public function minus($a, $b)

    {

        return $a - $b;

    }

}$di = new DI();$di->calc = 'Calc'; 

$di->demo = 'Demo';$di->demo;//输出结果为3