试图通过控制台应用程序了解PSR-4自动加载。(Trying to understand PSR-4 autoloading through a console app. What am I doing wrong?)

 我试图通过编写一个在控制台上运行的非常基本的示例应用程序来了解PSR-4自动加载。 
 
 这是我的应用程序（目录）结构： 
 
 app/ -library/auth/Author/AuthorInterface.php -library/auth/Author/Author.php -library/auth/Authorize/ -library/database/ -vendor/composer/ -vendor/autoload.php -composer.json -composer.lock -composer.phar -manager.php 
 
 我要做的就是运行manager.php并让它回应Author.php的return语句 
 
 AuthorInterface.php： 
 
namespace Vee\Auth\Author;

interface AuthorInterface
{
    public function write();
}
 
 Author.php 
 
namespace Vee\Auth\Author;

class Author implements AuthorInterface
{
    function __construct()
    {
        return "Hello";
    }

    public function write()
    {
        return "Hello.write";
    }
}
 
 manager.php： 
 
require "vendor/autoload.php";

use Vee\Auth\Author;

echo new Author();
 
 composer.json： 
 
{
    "autoload": {
        "psr-4": {
            "Vee\\": "library/"
        }
    },
    "require": {
        "monolog/monolog": "^1.21"
    }
}
 
 以下是我尝试运行manager.php时看到的错误： 
 
$ php manager.php 

Fatal error: Class 'Vee\Auth\Author' not found in /<path-to-app>/manager.php on line 7
 
 我已经运行： 
 
$ php composer.phar update

Loading composer repositories with package information
Updating dependencies (including require-dev)
Nothing to install or update
Writing lock file
Generating autoload files
 
 我错过了什么？ 
 
 编辑： 
 
 我在Mac上运行PHP 5.5，如果这有什么区别 - 
 
$ php --version
PHP 5.5.36 (cli) (built: Jun 12 2016 23:47:46) 
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies

I'm trying to understand PSR-4 autoloading by writing a very basic example app that runs on the console.
 
Here is my app's (directory) structure:
 
app/ -library/auth/Author/AuthorInterface.php -library/auth/Author/Author.php -library/auth/Authorize/ -library/database/ -vendor/composer/ -vendor/autoload.php -composer.json -composer.lock -composer.phar -manager.php 
 
All I'm trying to do is run manager.php and have it echo a return statement from Author.php
 
AuthorInterface.php: 
 
namespace Vee\Auth\Author;

interface AuthorInterface
{
    public function write();
}
 
Author.php 
 
namespace Vee\Auth\Author;

class Author implements AuthorInterface
{
    function __construct()
    {
        return "Hello";
    }

    public function write()
    {
        return "Hello.write";
    }
}
 
manager.php: 
 
require "vendor/autoload.php";

use Vee\Auth\Author;

echo new Author();
 
composer.json:
 
{
    "autoload": {
        "psr-4": {
            "Vee\\": "library/"
        }
    },
    "require": {
        "monolog/monolog": "^1.21"
    }
}
 
And here's the error that I see when I try to run manager.php:
 
$ php manager.php 

Fatal error: Class 'Vee\Auth\Author' not found in /<path-to-app>/manager.php on line 7
 
I have already run:
 
$ php composer.phar update

Loading composer repositories with package information
Updating dependencies (including require-dev)
Nothing to install or update
Writing lock file
Generating autoload files
 
What am I missing?
 
EDIT:
 
I'm running PHP 5.5 on a Mac, if that makes any difference-
 
$ php --version
PHP 5.5.36 (cli) (built: Jun 12 2016 23:47:46) 
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies

原文：https://stackoverflow.com/questions/39718783