PHP如何使用反射API(Reflection API)_PHP反射API应用详解

Reflection

ReflectionClass

ReflectionClass

<?php
class MyClass {
    private $property = 'Hello';
    public static $staticProperty = 'World';

    public function __construct($arg) {
        // ...
    }

    public function myMethod($param1, int $param2) {
        return "Method called with: {$param1}, {$param2}";
    }

    private function privateMethod() {
        return "This is private.";
    }
}

$reflector = new ReflectionClass('MyClass');

// 获取类名
echo "Class Name: " . $reflector->getName() . "\n";

// 获取公共方法
$methods = $reflector->getMethods(ReflectionMethod::IS_PUBLIC);
echo "Public Methods:\n";
foreach ($methods as $method) {
    echo "- " . $method->getName() . "\n";
}

// 获取所有属性
$properties = $reflector->getProperties();
echo "Properties:\n";
foreach ($properties as $property) {
    echo "- " . $property->getName() . " (Visibility: " . ($property->isPublic() ? 'public' : ($property->isProtected() ? 'protected' : 'private')) . ")\n";
}
?>

ReflectionMethod

ReflectionProperty

<?php
// 实例化ReflectionMethod
$methodReflector = new ReflectionMethod('MyClass', 'myMethod');
echo "Method Name: " . $methodReflector->getName() . "\n";

// 获取方法参数
$parameters = $methodReflector->getParameters();
echo "Method Parameters:\n";
foreach ($parameters as $param) {
    echo "- " . $param->getName() . " (Type: " . ($param->hasType() ? $param->getType()->getName() : 'none') . ")\n";
}

// 实例化ReflectionProperty
$propertyReflector = new ReflectionProperty('MyClass', 'property');
echo "Property Name: " . $propertyReflector->getName() . "\n";
echo "Is Private: " . ($propertyReflector->isPrivate() ? 'Yes' : 'No') . "\n";

// 示例：动态调用方法和访问属性
$instance = new MyClass('init');

// 调用公共方法
$result = $methodReflector->invokeArgs($instance, ['arg1', 123]);
echo "Method Call Result: " . $result . "\n";

// 访问并修改私有属性 (需要设置可访问性)
$propertyReflector->setAccessible(true); // 允许访问私有属性
$currentValue = $propertyReflector->getValue($instance);
echo "Current private property value: " . $currentValue . "\n";
$propertyReflector->setValue($instance, 'New Value');
echo "New private property value: " . $propertyReflector->getValue($instance) . "\n";

// 调用私有方法
$privateMethodReflector = new ReflectionMethod('MyClass', 'privateMethod');
$privateMethodReflector->setAccessible(true);
$privateResult = $privateMethodReflector->invoke($instance);
echo "Private Method Call Result: " . $privateResult . "\n";
?>

ReflectionFunction

ReflectionParameter

ReflectionExtension

ReflectionGenerator

ReflectionZendExtension

new

<?php
// 假设这是一个简单的DI容器
class Container {
    private $definitions = [];

    public function set(string $id, callable $concrete) {
        $this->definitions[$id] = $concrete;
    }

    public function get(string $id) {
        if (isset($this->definitions[$id])) {
            return $this->definitions[$id]($this);
        }

        // 如果没有定义，尝试通过反射自动解析
        if (!class_exists($id)) {
            throw new Exception("Class or service '{$id}' not found.");
        }

        $reflector = new ReflectionClass($id);
        $constructor = $reflector->getConstructor();

        if (is_null($constructor)) {
            return $reflector->newInstance();
        }

        $dependencies = [];
        foreach ($constructor->getParameters() as $parameter) {
            $type = $parameter->getType();
            if ($type && !$type->isBuiltin()) { // 检查是否是类类型
                $dependencies[] = $this->get($type->getName());
            } else {
                // 处理非类类型参数，或者抛出错误，或者使用默认值
                throw new Exception("Cannot resolve parameter '{$parameter->getName()}' for class '{$id}'.");
            }
        }
        return $reflector->newInstanceArgs($dependencies);
    }
}

class Logger { /* ... */ }
class Mailer {
    public function __construct(Logger $logger) {
        // ...
    }
}

$container = new Container();
$container->set(Logger::class, fn() => new Logger());

$mailer = $container->get(Mailer::class); // Mailer会自动注入Logger
// ...
?>

#[Route('/users', methods: ['GET'])]

<?php
// 假设有一个简单的路由注解处理器
#[Attribute(Attribute::TARGET_METHOD)]
class Route {
    public string $path;
    public array $methods;

    public function __construct(string $path, array $methods = ['GET']) {
        $this->path = $path;
        $this->methods = $methods;
    }
}

class UserController {
    #[Route('/users', methods: ['GET'])]
    public function index() {
        return "List of users";
    }

    #[Route('/users/{id}', methods: ['GET'])]
    public function show(int $id) {
        return "Showing user {$id}";
    }
}

// 模拟路由扫描
$reflector = new ReflectionClass(UserController::class);
foreach ($reflector->getMethods() as $method) {
    $attributes = $method->getAttributes(Route::class);
    foreach ($attributes as $attribute) {
        $route = $attribute->newInstance();
        echo "Registering route: " . $route->path . " for method " . $method->getName() . "\n";
    }
}
?>

ReflectionMethod

invoke()

invokeArgs()

invoke()

invokeArgs()

<?php
class ServiceProcessor {
    public function processData(array $data, string $type) {
        return "Processing " . count($data) . " items of type '{$type}'.";
    }

    private function logActivity(string $message) {
        return "Logged: {$message}";
    }
}

$config = [
    'class' => 'ServiceProcessor',
    'method' => 'processData',
    'args' => [['item1', 'item2'], 'report']
];

try {
    $classReflector = new ReflectionClass($config['class']);
    $instance = $classReflector->newInstance(); // 创建对象实例

    $methodReflector = $classReflector->getMethod($config['method']);

    // 检查方法是否可访问（比如是私有或保护方法）
    if (!$methodReflector->isPublic()) {
        $methodReflector->setAccessible(true); // 如果是私有或保护方法，强制设为可访问
    }

    $result = $methodReflector->invokeArgs($instance, $config['args']);
    echo "Dynamic method call result: " . $result . "\n";

    // 尝试动态调用私有方法
    $privateMethodReflector = $classReflector->getMethod('logActivity');
    $privateMethodReflector->setAccessible(true);
    $privateResult = $privateMethodReflector->invoke($instance, 'User accessed report.');
    echo "Dynamic private method call result: " . $privateResult . "\n";

} catch (ReflectionException $e) {
    echo "Error: " . $e->getMessage() . "\n";
}
?>

setAccessible(true)

public

protected

private

ReflectionProperty

getValue()

setValue()

setAccessible(true)

<?php
class Configuration {
    private array $settings = [
        'debugMode' => false,
        'databaseHost' => 'localhost'
    ];

    public string $appName = 'MyApp';
}

$configObj = new Configuration();

// 动态访问公共属性
$appNameReflector = new ReflectionProperty(Configuration::class, 'appName');
echo "Current app name: " . $appNameReflector->getValue($configObj) . "\n";
$appNameReflector->setValue($configObj, 'MyNewApp');
echo "New app name: " . $appNameReflector->getValue($configObj) . "\n";

// 动态访问私有属性
$settingsReflector = new ReflectionProperty(Configuration::class, 'settings');
$settingsReflector->setAccessible(true); // 允许访问私有属性

$currentSettings = $settingsReflector->getValue($configObj);
echo "Current private settings: " . json_encode($currentSettings) . "\n";

// 修改私有属性
$currentSettings['debugMode'] = true;
$settingsReflector->setValue($configObj, $currentSettings);
echo "Modified private settings: " . json_encode($settingsReflector->getValue($configObj)) . "\n";
?>

toArray()