autocde2.0/app/Http/Requests/API/File/DownloadRequest.php

<?php

namespace App\Http\Requests\API\File;

use App\Http\Requests\RuleHelper;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Support\Facades\Storage;

class DownloadRequest extends FormRequest
{
    use RuleHelper;
    /**
     * Determine if the user is authorized to make this request.
     */
    public function authorize(): bool
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
     */
    public function rules(): array
    {
        return [
            'url' => [
                'required',
                function ($attribute, $value, $fail) {
                    // 检查文件是否存在默认存储对象系统中
                    if (!Storage::exists($value)) {
                        $fail('url file does not exist');
                    }
                },
            ],
        ];
    }
}