When you start a new Laravel project, error and exception handling is already configured for you. The App\Exceptions\Handler class is where all exceptions triggered by your application are logged and then rendered back to the user. We'll dive deeper into this class throughout this documentation.
For logging, Laravel utilizes the Monolog library, which provides support for a variety of powerful log handlers. Laravel configures several of these handlers for you, allowing you to choose between a single log file, rotating log files, or writing error information to the system log.
你的应用程序通过 config/app.php 配置文件中的 debug 设置选项来控制浏览器对错误的细节显示。默认情况下，此设置选项是参照于保存在 .env 文件的 APP_DEBUG 环境变量。
在开发的时候，你应该将 APP_DEBUG 环境变量设置为 true。在你的上线环境中，这个值应该永远为 false。 If the value is set to true in production, you risk exposing sensitive configuration values to your application's end users.
Laravel 提供可立即使用的 single、daily、syslog 和 errorlog 日志模式。例如，如果你想要每天保存一个日志文件，而不是单个文件，则可以在 config/app.php 配置文件内设置 log 变量：
'log' => 'daily'
当使用「日志模式」时，默认情况下会保存 5 天的日志，你可通过 app.php 配置文件里的配置项 log_max_files 来定制日志保存天数：
'log_max_files' => 30
When using Monolog, log messages may have different levels of severity. By default, Laravel writes all log levels to storage. However, in your production environment, you may wish to configure the minimum severity that should be logged by adding the log_level option to your app.php configuration file.
Once this option has been configured, Laravel will log all levels greater than or equal to the specified severity. For example, a default log_level of error will log error, critical, alert, and emergency messages:
'log_level' => env('APP_LOG_LEVEL', 'error'),
{tip} Monolog recognizes the following severity levels - from least severe to most severe:
debug,info,notice,warning,error,critical,alert,emergency.
如果你想要完全控制 Monolog，则使用应用程序的 configureMonologUsing 方法。此方法应该在 bootstrap/app.php 文件返回 $app 变量之前被调用：
$app->configureMonologUsing(function($monolog) {
$monolog->pushHandler(...);
});
return $app;
All exceptions are handled by the App\Exceptions\Handler class. This class contains two methods: report and render. We'll examine each of these methods in detail. The report method is used to log exceptions or send them to an external service like Bugsnag or Sentry. By default, the report method simply passes the exception to the base class where the exception is logged. However, you are free to log exceptions however you wish.
For example, if you need to report different types of exceptions in different ways, you may use the PHP instanceof comparison operator:
/**
* Report or log an exception.
*
* This is a great spot to send exceptions to Sentry, Bugsnag, etc.
*
* @param \Exception $exception
* @return void
*/
public function report(Exception $exception)
{
if ($exception instanceof CustomException) {
//
}
return parent::report($exception);
}
The $dontReport property of the exception handler contains an array of exception types that will not be logged. For example, exceptions resulting from 404 errors, as well as several other types of errors, are not written to your log files. You may add other exception types to this array as needed:
/**
* A list of the exception types that should not be reported.
*
* @var array
*/
protected $dontReport = [
\Illuminate\Auth\AuthenticationException::class,
\Illuminate\Auth\Access\AuthorizationException::class,
\Symfony\Component\HttpKernel\Exception\HttpException::class,
\Illuminate\Database\Eloquent\ModelNotFoundException::class,
\Illuminate\Validation\ValidationException::class,
];
The render method is responsible for converting a given exception into an HTTP response that should be sent back to the browser. By default, the exception is passed to the base class which generates a response for you. However, you are free to check the exception type or return your own custom response:
/**
* Render an exception into an HTTP response.
*
* @param \Illuminate\Http\Request $request
* @param \Exception $exception
* @return \Illuminate\Http\Response
*/
public function render($request, Exception $exception)
{
if ($exception instanceof CustomException) {
return response()->view('errors.custom', [], 500);
}
return parent::render($request, $exception);
}
Some exceptions describe HTTP error codes from the server. For example, this may be a "page not found" error (404), an "unauthorized error" (401) or even a developer generated 500 error. In order to generate such a response from anywhere in your application, you may use the abort helper:
abort(404);
The abort helper will immediately raise an exception which will be rendered by the exception handler. Optionally, you may provide the response text:
abort(403, 'Unauthorized action.');
Laravel makes it easy to display custom error pages for various HTTP status codes. For example, if you wish to customize the error page for 404 HTTP status codes, create a resources/views/errors/404.blade.php. This file will be served on all 404 errors generated by your application. The views within this directory should be named to match the HTTP status code they correspond to. The HttpException instance raised by the abort function will be passed to the view as an $exception variable.
Laravel provides a simple abstraction layer on top of the powerful Monolog library. By default, Laravel is configured to create a log file for your application in the storage/logs directory. You may write information to the logs using the Log facade:
<?php
namespace App\Http\Controllers;
use App\User;
use Illuminate\Support\Facades\Log;
use App\Http\Controllers\Controller;
class UserController extends Controller
{
/**
* Show the profile for the given user.
*
* @param int $id
* @return Response
*/
public function showProfile($id)
{
Log::info('Showing user profile for user: '.$id);
return view('user.profile', ['user' => User::findOrFail($id)]);
}
}
The logger provides the eight logging levels defined in RFC 5424: emergency, alert, critical, error, warning, notice, info and debug.
Log::emergency($message);
Log::alert($message);
Log::critical($message);
Log::error($message);
Log::warning($message);
Log::notice($message);
Log::info($message);
Log::debug($message);
An array of contextual data may also be passed to the log methods. This contextual data will be formatted and displayed with the log message:
Log::info('User failed to login.', ['id' => $user->id]);
Monolog has a variety of additional handlers you may use for logging. If needed, you may access the underlying Monolog instance being used by Laravel:
$monolog = Log::getMonolog();