在Laravel 5.1中找不到“Class'app \ Http \ Controllers \ Controller'

I'm quite new to Laravel and when I am going through a tutorial when I encountered this error. This is my code in 'testController.php'.

<?php

namespace app\Http\Controllers;

use app\Http\Controllers\Controller;

class testController extends \app\Http\Controllers\Controller {

public function getAbout()
{
    return view('Learning.about') ;
}

public function getHome()
{
    return view('Learning.index');
}

}

And this is my 'routes.php'.

<?php
Route::get('test', [
   'as' => 'test', 
   'uses' => 'testController@getHome',
]);

Route::get('about', [
    'as' => 'about', 
    'uses' => 'testController@getAbout',
]);

I am getting this error:

Class 'app\Http\Controllers\Controller' not found

How can I fix this error?

Let's go through this step by step.

1. Check autoload directive on composer.json

Open composer.json file on your project root directory. Locate the the autoload section. It should be looking like this:

{
    ...
    "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "App\\": "app/"
        }
    },
}

Make sure you have this configuration under the psr-4 option:

"App\\": "app/"

This configuration tells the composer that we want to autoload all classes inside the app directory using psr-4 convention and places it under the App namespace.

2. Update your controller

First, your controller file name should be in CamelCase style. So we have to renamed it to TestController.php. Make sure that it's saved under app/Http/Controllers directory.

Now open your TestController.php file, we have to capitalize the namespace and class name like so:

<?php

namespace App\Http\Controllers;

use App\Http\Controllers\Controller;

class TestController extends Controller {
    public function getAbout()
    {
        return view('Learning.about') ;
    }

    public function getHome()
    {
        return view('Learning.index');
    }
}

Note that we also turn this line:

class testController extends \app\Http\Controllers\Controller

Into:

class TestController extends Controller

Since we already import the base Controller class, we don't have to specify the fully qualified name. We imported the Controller class using the use keyword:

use App\Http\Controllers\Controller;

Save your TestController.php file.

3. Update your routes file

Now we have to update our app\Httpoutes.php file. We just need to capitalize the controller name:

<?php

Route::get('test', ['uses' => 'TestController@getHome', 'as' => 'test']);

Route::get('about', ['uses' => 'TestController@getAbout', 'as' => 'about']);

4 Update your autoloader

Now the last thing to do. Open your terminal / command prompt. Go to your project directory and run the following command:

composer dump-autoload

This command will update the autoloader file (Read more here).

Now if you open up your browser and hit /test route, you should see the content from resources/views/Learning/index.blade.

Use correct namespace:

namespace App\Http\Controllers;

// Remove: use app\Http\Controllers\Controller;

class testController extends Controller {

According to my experience in Laravel projects, the namespaces starts with the capital A of App used in namespace, you should try to change your code to this:

namespace App\Http\Controllers;

class testController extends Controller { }

Also check if the controller - App\Http\Controllers\Controller lies in the same namespace as mentioned in your code.

Include this at the top of your Controller file. This fixed it for me.

namespace App\Http\Controllers;