在 Laravel 5.4 ( Symfony )中，检测上传文件的扩展名

1、上传图片文件时报错，原因在于上传了 gif 格式的图片，当做了 JPEG 格式来处理。如图1

图1

{
  "code": 1,
  "message": "success",
  "result": "imagecreatefromjpeg(): gd-jpeg: JPEG library reports unrecoverable error: Not a JPEG file: starts with 0x47 0x49"
}

2、查看相应代码实现。

    public function upload(Request $request, StorageService $storageService)
    {
        $files = $request->files->all();
        try {
            $logoImages = $storageService->storeAsTmpImage($files['upfile'], ['ext' => 'csv']);

            return $this->respondJson(['result' => $logoImages['url']]);
        } catch (/Exception $e) {
            return $this->respondJson(['result' => $e->getMessage(), 'code' => 1]);
        }
    }

3、决定在收到请求后，先判断一下文件的扩展名。参考网址：https://github.com/symfony/symfony/blob/3.0/src/Symfony/Component/HttpFoundation/File/UploadedFile.php 。返回原始文件扩展名。使用方法：getClientOriginalExtension() 。如图2

图2

4、获取文件扩展名，转换为小写字母。再判断范围。相应代码实现。

    public function upload(Request $request, StorageService $storageService)
    {
        $files = $request->files->all();
		$extension = strtolower($files['upfile']->getClientOriginalExtension());
		if (!in_array($extension, ['jpg', 'jpeg', 'png'])) {
			return $this->respondJson([
				'code' => 1,
				'message' => '格式错误，仅支持PNG、JPG格式',
			]);
		}
        try {
            $logoImages = $storageService->storeAsTmpImage($files['upfile'], ['ext' => 'csv']);

            return $this->respondJson(['result' => $logoImages['url']]);
        } catch (/Exception $e) {
            return $this->respondJson(['result' => $e->getMessage(), 'code' => 1]);
        }
    }

5、上传图片：2 – 副本.GIF，提示图片上传失败：格式错误，仅支持PNG、JPG格式，符合预期。提示信息有待于前端基于接口响应完善。如图3

图3

{
  "code": 1,
  "message": "格式错误，仅支持PNG、JPG格式"
}