Symfony2：如何显示/下载BLOB字段

For my client I have to use blob storage for some various files.

对于我的客户端，我必须使用blob存储来处理各种文件。

So I have created a independent bundle with a Blob class extends Doctrine\DBAL\Types\Type. and with a boot function in the bundle class.

所以我创建了一个独立的bundle，其中一个Blob类扩展了Doctrine \ DBAL \ Types \ Type。并在bundle类中使用引导函数。

That works pretty fine I can write in the database Blob datas.

这很好，我可以写在数据库Blob数据中。

But I can't download any document after :/

但我无法下载任何文件后：/

I have got:

我有：

public function downloadAction($id) {
    $em = $this->getDoctrine()->getManager();

    /* @var $entity Document */
    $entity = $em->getRepository('Lille3SapBundle:Document')->find($id);

    if (!$entity) {
        throw $this->createNotFoundException('Unable to find Document entity.');
    }

    $file = $entity->getFichier();

    $response = new \Symfony\Component\HttpFoundation\Response($file, 200, array(
        'Content-Type' => 'application/octet-stream',
        'Content-Length' => sizeof($file),
        'Content-Disposition' => 'attachment; filename="'.$entity->getNomDocument().'"',
    ));

    return $response;
}

and I have got an Exception: The Response content must be a string or object implementing __toString(), "resource" given.

我有一个例外：响应内容必须是一个字符串或对象，实现__toString（），给定“资源”。

in fact, the $file values is not the expected BLOB but something like Resource id #123

实际上，$ file值不是预期的BLOB，而是类似于资源ID＃123

-> I have check blob data fields values, and they are ok in the database

- >我检查了blob数据字段值，它们在数据库中没问题

So how can I force in the controller to have the blob row and not a Resource id #111

那么我如何强制控制器中的blob行而不是资源ID＃111

2 个解决方案

#1

You can still use BLOB field for your field in DB as you initially planned.

您仍然可以按照最初计划在数据库中为您的字段使用BLOB字段。

In createAction store data as usual (with no base64_encode()):

在createAction中像往常一样存储数据（没有base64_encode（））：

$stream = fopen($entity->getFichier(),'rb');
$entity->setFichier(stream_get_contents($stream));

and in downloadAction just use:

并在downloadAction中使用：

$file = $entity->getFichier();
$response = new \Symfony\Component\HttpFoundation\Response(stream_get_contents($file), 200, array(
    'Content-Type' => 'application/octet-stream',
    'Content-Length' => sizeof($file),
    'Content-Disposition' => 'attachment; filename="'.$entity->getNomDocument().'"',
));

return $response;

Explanation:

说明：

BLOB fields are treated as resource variable which have no __toString() implementation.

BLOB字段被视为没有__toString（）实现的资源变量。

gettype($file) -> "resource"
get_resource_type($file) -> "stream"

stream_get_contents($file) makes the magic here: gets STRING content from resource variable.

stream_get_contents（$ file）在这里发挥作用：从资源变量中获取STRING内容。

#2

Okay, I have got a (very uggly) solution:

好的，我有一个（非常好的）解决方案：

Firstly: I changed the data type blob to text for the file attribute of Document entity.

首先：我将数据类型blob更改为文本实体的文件属性的文本。

Secondly: in createAction I've changed the setFichier call:

其次：在createAction中我改变了setFichier调用：

$stream = fopen($entity->getFichier(),'rb');
$entity->setFichier(base64_encode(stream_get_contents($stream)));

Thirdly: in downloadAction, I decode the text base64 text field:

第三：在downloadAction中，我解码文本base64文本字段：

$file = $entity->getFichier();              
$response = new \Symfony\Component\HttpFoundation\Response(base64_decode($file), 200, array(
        'Content-Type' => 'application/octet-stream',
        'Content-Length' => sizeof($file),
        'Content-Disposition' => 'attachment; filename="'.$entity->getNomDocument().'"',
));

return $response;

And now I can persist and download files as blob way...

现在我可以坚持下载文件作为blob方式...

#1