Get property's constraints
$validator = $this->getConfigurationPool()->getContainer()->get('validator');
$meta = $validator->getMetadataFor(get_class($this->getSubject()));
$allowableTypes = null;
$maxSize = null;
foreach ($meta->properties['resumeFile']->getConstraints() as $constraint) {
if ($constraint instanceof File) {
$allowableTypes = $constraint->mimeTypes;
$allowableTypes = implode(', ', $allowableTypes);
$maxSize = $constraint->maxSize/pow(10, 3);
}
}