Laravel：从S3私有存储桶返回文件内容以在浏览器中显示

// app/Services/S3FileService.php (示例)

namespace App\Services;

use Illuminate\Support\Facades\Storage;

class S3FileService

{

    protected $disk;

    public function __construct()

    {

        // 假设你配置了一个名为 s3_private 的S3磁盘

        $this->disk = Storage::disk(s3_private);

    }

    public function getPrivateFileContents(string $filePath): ?string

    {

        if ($this->disk->exists($filePath)) {

            return $this->disk->get($filePath);

        }

        return null;

    }

    public function getFileMimeType(string $filePath): ?string

    {

        if ($this->disk->exists($filePath)) {

            return $this->disk->mimeType($filePath);

        }

        return null;

    }

}

// app/Http/Controllers/FileController.php (示例)

namespace App\Http\Controllers;

use App\Services\S3FileService;

use Illuminate\Http\Request;

use Symfony\Component\HttpFoundation\Response;

class FileController extends Controller

{

    protected $s3FileService;

    public function __construct(S3FileService $s3FileService)

    {

        $this->s3FileService = $s3FileService;

    }

    public function showPrivateFile(string $filename)

    {

        // 假设 $filePath 是在S3上的完整路径，例如 images/example.png

        // 你可能需要根据 $filename 从数据库或其他地方解析出真实的S3路径

        $filePath = path/to/your/private/files/ . $filename;

        $fileContent = $this->s3FileService->getPrivateFileContents($filePath);

        if (is_null($fileContent)) {

            // 文件不存在或无法访问

            abort(404, 文件未找到);

        }

        $mimeType = $this->s3FileService->getFileMimeType($filePath);

        // 如果无法通过S3获取MIME类型，可以尝试根据文件内容或扩展名猜测

        if (is_null($mimeType)) {

            $mimeType = mime_content_type_from_content($fileContent, $filename); // 自定义辅助函数或库

        }

        // 构建响应

        return response($fileContent)

                ->header(Content-Type, $mimeType)

                ->header(Content-Length, strlen($fileContent))

                // 确保不发送 Content-Disposition: attachment

                ->header(Content-Disposition, inline; filename=" . basename($filename) . ");

    }

}

// 辅助函数示例 (如果需要从内容猜测MIME类型)

if (!function_exists(mime_content_type_from_content)) {

    function mime_content_type_from_content(string $content, string $filename = null): string

    {

        // 尝试使用 fileinfo 扩展

        if (extension_loaded(fileinfo)) {

            $finfo = new \finfo(FILEINFO_MIME_TYPE);

            return $finfo->buffer($content);

        }

        // 备用方案：根据文件扩展名猜测

        if ($filename) {

            $extension = pathinfo($filename, PATHINFO_EXTENSION);

            switch (strtolower($extension)) {

                case png: return image/png;

                case jpg:

                case jpeg: return image/jpeg;

                case gif: return image/gif;

                case pdf: return application/pdf;

                case txt: return text/plain;

                // 添加更多MIME类型映射

                default: return application/octet-stream; // 默认二进制流

            }

        }

        return application/octet-stream;

    }

}

use App\Http\Controllers\FileController;

Route::get(/files/{filename}, [FileController::class, showPrivateFile])->name(show.private.file);