Zend framework2 为实例“UserService”找到LazyServiceLoader的循环依赖项`

在Zend框架2中

我有一个控制器类

UserController

• UserController

  依赖于

  UserService

• UserService

  依赖于

  UserChangedListener

• UserChangedListener

  依赖于

  SomeOtherClass

• SomeOtherClass

  依赖于

  UserService

因此这里我的

UserController

和

SomeOtherClass

依赖于

UserService

我得到一个错误：

例如，找到LazyServiceLoader的循环依赖项

UserService

当我在

UserChangedListener

我有

“zendframework/zend servicemanager”：“^2.7.5 | | ^3.0.3”

UserControllerFactory.php

class UserControllerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserController(
            $container->get(UserService::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserController::class);
    }

}

class UserServiceFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $service = new UserService(
            $container->get(UserRepository::class)
        );

        $eventManager = $service->getEventManager();
        $eventManager->attach($container->get(UserChangedListener::class));

        return $service;
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserService::class);
    }
}

class UserChangedListenerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserChangedListener(
            $container->get(SomeOtherClass::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserChangedListener::class);
    }
}

class SomeOtherClassFactory implements FactoryInterface
{
    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        $rootLocator = $serviceLocator->getServiceLocator();

        return new SomeOtherClass(
            $rootLocator->get(UserService::class)
        );
    }
}

UserServiceFactory.php

class UserControllerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserController(
            $container->get(UserService::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserController::class);
    }

}

class UserServiceFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $service = new UserService(
            $container->get(UserRepository::class)
        );

        $eventManager = $service->getEventManager();
        $eventManager->attach($container->get(UserChangedListener::class));

        return $service;
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserService::class);
    }
}

class UserChangedListenerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserChangedListener(
            $container->get(SomeOtherClass::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserChangedListener::class);
    }
}

class SomeOtherClassFactory implements FactoryInterface
{
    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        $rootLocator = $serviceLocator->getServiceLocator();

        return new SomeOtherClass(
            $rootLocator->get(UserService::class)
        );
    }
}

UserChangedListenerFactory.php

class UserControllerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserController(
            $container->get(UserService::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserController::class);
    }

}

class UserServiceFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $service = new UserService(
            $container->get(UserRepository::class)
        );

        $eventManager = $service->getEventManager();
        $eventManager->attach($container->get(UserChangedListener::class));

        return $service;
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserService::class);
    }
}

class UserChangedListenerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserChangedListener(
            $container->get(SomeOtherClass::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserChangedListener::class);
    }
}

class SomeOtherClassFactory implements FactoryInterface
{
    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        $rootLocator = $serviceLocator->getServiceLocator();

        return new SomeOtherClass(
            $rootLocator->get(UserService::class)
        );
    }
}

SomeOtherClassFactory.php

class UserControllerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserController(
            $container->get(UserService::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserController::class);
    }

}

class UserServiceFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $service = new UserService(
            $container->get(UserRepository::class)
        );

        $eventManager = $service->getEventManager();
        $eventManager->attach($container->get(UserChangedListener::class));

        return $service;
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserService::class);
    }
}

class UserChangedListenerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
    {
        $container = $container->getServiceLocator();

        return new UserChangedListener(
            $container->get(SomeOtherClass::class)
        );
    }

    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        return $this($serviceLocator, UserChangedListener::class);
    }
}

class SomeOtherClassFactory implements FactoryInterface
{
    public function createService(ServiceLocatorInterface $serviceLocator)
    {
        $rootLocator = $serviceLocator->getServiceLocator();

        return new SomeOtherClass(
            $rootLocator->get(UserService::class)
        );
    }
}

---

看起来您与

UserService

有合法的循环依赖关系。错误消息告诉您，如果没有

UserService

，则无法创建

UserService

通过

\uu-construct

方法使用依赖项注入的良好实践确实带来了这个问题。通过这样做，ZF2将eager将一个非常大的对象图加载到内存中，当您有大量具有复杂嵌套关系的相关“服务”时，您必然会有循环依赖关系

ZF2确实提供了一种解决方案来延迟某些对象的实例化，作为开发人员，您需要决定哪些对象（我建议

UserChangedListener

）

或者，要更新代码，可以将侦听器代码的注册移到

UserServiceFactory

之外的

Module:：onBootstrap（）

方法中

namespace User;

class Module
{   
    public function onBootstrap(EventInterface $event)
    {
        $serviceManager = $event->getApplication()->getServiceManager();

        // Create the user service first
        $userService = $serviceManager->get(UserService::class);

        $listener = $serviceManager->get(UserChangedListener::class);

        // The create and attach the listener after user service has been created.
        $userService->getEventManager()->attach($listener);
    }

}

如果您使用的是“聚合”侦听器，则需要这样做。对于简单事件侦听器，您还可以使用

SharedEventManager

，这将防止在上述示例中加载

UserService

的开销。

• UserService

  依赖于

  SomeOtherClass

  UserChangedListener

• SomeOtherClass

  依赖于

  UserService

因此，基本上对于创建

UserService

您需要首先创建

SomeOtherClass

实例，但是对于创建它，您需要已经创建

UserService

实例

我不确定您的体系结构，但根据类名，在

UserService

中附加

UserChangedListener

似乎有点错误。

---

可能

UserService

应该只触发事件，而不应该知道有关此事件的侦听器的任何信息。但是，这只是一个想法，为了得到好的答案，您需要进一步解释这种依赖关系。

这是一个古老的响应，但请记住，使用

onBootstrap（）

将在每个请求上创建UserService和UserChangedListener！不只是在需要的时候！