<?phpnamespaceSymfony\Component\HttpFoundation;useSymfony\Component\HttpFoundation\Exception\ConflictingHeadersException;useSymfony\Component\HttpFoundation\Exception\SuspiciousOperationException;useSymfony\Component\HttpFoundation\Session\SessionInterface;/* 〜〜〜〜省略〜〜〜〜〜 */classRequest{/* 〜〜〜〜省略〜〜〜〜〜 *//**
     * Gets the mime type associated with the format.
     *
     * @return string|null The associated mime type (null if not found)
     */publicfunctiongetMimeType(string$format){if(null===static::$formats){static::initializeFormats();}returnisset(static::$formats[$format])?static::$formats[$format][0]:null;}/* 〜〜〜〜省略〜〜〜〜〜 */}

<?php/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */namespaceSymfony\Component\HttpFoundation\File;/* 〜〜〜〜省略〜〜〜〜〜 *//**
 * A file uploaded through a form.
 *
 * @author Bernhard Schussek <bschussek@gmail.com>
 * @author Florian Eckerstorfer <florian@eckerstorfer.org>
 * @author Fabien Potencier <fabien@symfony.com>
 */classUploadedFileextendsFile{/* 〜〜〜〜省略〜〜〜〜〜 *//**
     * Returns the file mime type.
     *
     * The client mime type is extracted from the request from which the file
     * was uploaded, so it should not be considered as a safe value.
     *
     * For a trusted mime type, use getMimeType() instead (which guesses the mime
     * type based on the file content).
     *
     * @return string The mime type
     *
     * @see getMimeType()
     */publicfunctiongetClientMimeType(){return$this->mimeType;}/* 〜〜〜〜省略〜〜〜〜〜 */}

Route::get('/file/upload','LectureController@index');Route::post('/file/upload','LectureController@upload');

<?phpnamespaceApp\Http\Controllers;useIlluminate\Http\Request;classFileUploadControllerextendsController{publicfunctionindex(){returnview('file.upload');}publicfunctionupload(Request$request){$images=$request->file('images');foreach($imagesas$image){logger('拡張子: '.$image->getClientOriginalExtension());logger('getMimeType(): '.$image->getMimeType());logger('getClientMimeType(): '.$image->getClientMimeType());}returnredirect('/file/upload');}}

<div><formaction="/file/upload"method="POST"enctype='multipart/form-data'>
        @csrf
        <h2>画像アップロード</h2><div><inputtype="file"name="images[]"multiple="multiple"></div><buttontype="submit">更新</button></form></div>

[2021-02-23 12:58:26] stack-channel.DEBUG: 拡張子: pdf  
[2021-02-23 12:58:26] stack-channel.DEBUG: getMimeType(): application/pdf  
[2021-02-23 12:58:26] stack-channel.DEBUG: getClientMimeType(): application/pdf