Symfony2表单，不匹配实体

我遵循'如何'在Symfony 2中实现注册表单我创建了Registration和RegistrationType，就像教程一样。

我还创建了User实体和UserType。一切都是相等的，但是我在提交表单时收到了一个Exception。

Catchable Fatal Error: Argument 1 passed to My'Bundle'Form'Model'Registration::setUser() must be an instance of My'Bundle'Entity'User, array given

因为在Registration.php中:

public function setUser(User $user)
{
    $this->user = $user;
}

$user不是User，是array。这个数组有以下输入数据:

array (size=2)
'email' => string 'email@email.com' (length=15)
'password' => string 'password' (length=8)

为什么表单不"匹配"实体?

在UserType表单中，我配置了data_class:

public function configureOptions(OptionsResolver $resolver)
{
    $resolver->setDefaults(array(
        'data_class'        => 'My'Bundle'Entity'User',
    ));
}

UserType:

class UserType extends AbstractType
{
/**
 * @param FormBuilderInterface $builder
 * @param array $options
 */
public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('email', 'text')
        ->add('password', 'repeated', array(
            'first_name'    => 'password',
            'second_name'   => 'confirm',
            'type'          => 'password'
        ))
        ;
}
/**
 * @param OptionsResolver $resolver
 */
public function configureOptions(OptionsResolver $resolver)
{
    $resolver->setDefaults(array(
        'data_class'        => 'My'Bundle'Entity'User',
    ));
}
/**
 * @return string
 */
public function getName()
{
    return 'user';
}
}

RegistrationType:

class RegistrationType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->add('user', new UserType());
    $builder->add('terms', 'checkbox', array('property_path' => 'termsAccepted'));
    $builder->add('Register', 'submit');
}
public function getName()
{
    return 'registration';
}
}

注册:

class Registration {
/**
 * @Assert'Type(type="My'Bundle'Entity'User")
 * @Assert'Valid()
 */
protected $user;
/**
 * @Assert'NotBlank()
 * @Assert'True()
 */
protected $termsAccepted;

public function setUser(User $user)
{
    $this->user = $user;
}
public function getUser()
{
    return $this->user;
}
public function getTermsAccepted()
{
    return $this->termsAccepted;
}
public function setTermsAccepted($termsAccepted)
{
    $this->termsAccepted = (bool) $termsAccepted;
}
}

行动:

public function registerProcessAction(Request $request){
    $em = $this->getDoctrine()->getManager();
    $form = $this->createForm(new RegistrationType(), new Registration());
    $form->handleRequest($request);
    if ($form->isValid()) {
        $registration = $form->getData();
        $em->persist($registration->getUser());
        $em->flush();
        return $this->redirectToRoute(...);
    }
    else{
        die('invalid');
    }

用户实体:

/**
 * Class User
 * @ORM'Entity
 * @UniqueEntity(fields="email", message="Email already taken")
 */
class User{
/**
 * @ORM'Id
 * @ORM'Column(type="integer")
 * @ORM'GeneratedValue(strategy="AUTO")
 */
private $id;

/**
 * @ORM'Column(type="string", length=150, unique=true)
 * @Assert'NotNull()
 * @Assert'Email()
 */
private $email;
/**
 * @ORM'Column(type="string", length=255)
 * @Assert'NotBlank()
 * @Assert'Length(max = 4096)
 */
private $password;
/** GETTERS **/
public function getId()
{
    return $this->id;
}
public function getEmail()
{
    return $this->email;
}
public function getPassword()
{
    return $this->password;
}
/** SETTERS **/
public function setEmail($email)
{
    $this->email = $email;
    return $this;
}
public function setPassword($password)
{
    $this->password = password_hash($password, PASSWORD_DEFAULT);
    return $this;
}
}