How to fix Uncaught exception 'ReflectionException' with message 'Class log does not exist'?

问题

I am facing an issue with composer on Windows Server 20012 R2. I am trying to deploy a website and every time I run composer install or composer update I get the following:

$ composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Nothing to install or update
Generating autoload files
> Illuminate\Foundation\ComposerScripts::postInstall
> php artisan optimize
Script php artisan optimize handling the post-install-cmd event returned with an error


  [RuntimeException]
  Error Output:


install [--prefer-source] [--prefer-dist] [--dry-run] [--dev] [--no-dev] [--no-custom-installers] [--no-autoloader] [--no-scripts] [--no-progress] [-v|vv|vvv|--verbose] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--ignore-platform-reqs] [--] [<packages>]...

And when I checked the php error log I find the following:

[17-Jul-2016 08:04:58 UTC] PHP Fatal error:  Uncaught exception 'ReflectionException' with message 'Class log does not exist' in C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\Container\Container.php:734
Stack trace:
#0 C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\Container\Container.php(734): ReflectionClass->__construct('log')
#1 C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\Container\Container.php(629): Illuminate\Container\Container->build('log', Array)
#2 C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\Foundation\Application.php(697): Illuminate\Container\Container->make('log', Array)
#3 C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\Container\Container.php(849): Illuminate\Foundation\Application->make('Psr\\Log\\LoggerI...')
#4 C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\ in C:\PATH_TO_PROJECT\vendor\laravel\framework\src\Illuminate\Container\Container.php on line 734

When I try the same project on an Ubuntu server everything works fin! I have tried every answer i could find on the internet, but nothing worked for me. Any advise on how to solve this? And why it is happening?

The windows server PHP version is 5.6.

composer.json file:

{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": ">=5.5.9",
        "laravel/framework": "5.2.*",
        "intervention/image": "^2.3",
        "greggilbert/recaptcha": "2.*",
        "laravelcollective/html": "5.2.*",
        "vsch/laravel-translation-manager": "*"
    },
    "require-dev": {
        "fzaninotto/faker": "~1.4",
        "mockery/mockery": "0.9.*",
        "phpunit/phpunit": "~4.0",
        "symfony/css-selector": "2.8.*|3.0.*",
        "symfony/dom-crawler": "2.8.*|3.0.*"
    },
    "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "App\\": "app/"
        },
         "files": ["app/Http/Helpers/helpers.php"]
    },
    "autoload-dev": {
        "classmap": [
            "tests/TestCase.php"
        ]
    },
    "scripts": {
        "post-root-package-install": [
            "php -r \"copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "php artisan key:generate"
        ],
        "post-install-cmd": [
            "Illuminate\\Foundation\\ComposerScripts::postInstall",
            "php artisan optimize"
        ],
        "post-update-cmd": [
            "Illuminate\\Foundation\\ComposerScripts::postUpdate",
            "php artisan optimize"
        ]
    },
    "config": {
        "preferred-install": "dist"
    }
}

回答1:

I was able to fix this issue by removing any space in the values in the .env file e.g.:

MAIL_PORT= 587
MAIL_FROM_NAME=ABC Medical

to:

MAIL_PORT=587
MAIL_FROM_NAME=ABCMedical

Or by using quotes:

MAIL_PORT=587
MAIL_FROM_NAME="ABC Medical"

回答2:

I got this error when passing values with spaces in .env without quotes, I fixed it by wrapping the values in quotes.

回答3:

have you try composer dump-autoload?

you might add a class without dump-autoload

回答4:

Most common reasons I can think of for this error to occur are the following:

1. Log class is called in a scope where it is not included with the USE statement.
2. A config file contains (parse) errors, which in turn does not allow your application to find the Log class. Check the files loaded early on in Laravel such as app.php.

来源：https://stackoverflow.com/questions/38419182/how-to-fix-uncaught-exception-reflectionexception-with-message-class-log-does