In Laravel development, exception handling and logging are very important parts, which can help us quickly locate problems and handle exceptions. This article will introduce how to handle exceptions and log records to help developers better develop Laravel.

1. Exception handling

Exception handling refers to catching the error and handling it accordingly when an error or unexpected situation occurs in the program. Laravel provides a wealth of exception handling mechanisms. Let's introduce the specific steps of exception handling.

1.1 Exception types

In Laravel, there are many different exceptions, each of which has its own specific meaning and handling method. The following are some common exception types:

• HTTP exception: When the requested route does not exist or an incorrect HTTP response code is returned, an HTTP exception will be thrown.
• Model not found exception: When using the Eloquent model, a model not found exception will be thrown when no matching records are found when querying the database.
• Validation exception: A validation exception will be thrown when form validation fails, which contains incorrect fields and error information.
• Database exception: When querying the database using Laravel's query builder or Eloquent, a database exception will be thrown if an error occurs.
• Other exceptions: In addition to the above exceptions, there are many other types of exceptions in Laravel, such as service exceptions, queue exceptions, etc.

1.2 Exception handling process

When an exception occurs, Laravel will decide how to handle it based on the type of exception. If it is some common exception, the framework will automatically handle it, usually returning a rendered error page or JSON response. If it is an exception of other types, the framework will throw the exception to the exception handler and handle it according to the configuration of the exception handler. The following is the general process of exception handling:

1.2.1 Create exception class

In Laravel, we can customize exception classes to better handle exceptions. Custom exception classes need to inherit the Exception class. The following is an example of a custom exception class:

namespace AppExceptions;

use Exception;

class CustomException extends Exception
{
    public function __construct($message = "", $code = 0, Exception $previous = null)
    {
        parent::__construct($message, $code, $previous);
    }

    public function render($request)
    {
        return response()->view('errors.custom', [], 500);
    }
}

In the above code, we created an exception class named CustomException and overridden the render method to customize it. Define exception handling.

1.2.2 Register exception handler

In Laravel, you can register an exception handler through AppServiceProvider or ExceptionHandler. Exception handlers can handle all types of exceptions in the system. The following is an example of registering an exception handler:

namespace AppProviders;

use IlluminateSupportServiceProvider;
use IlluminateContractsDebugExceptionHandler as ExceptionHandlerContract;
use AppExceptionsCustomExceptionHandler;

class AppServiceProvider extends ServiceProvider
{
    public function boot()
    {
        //
    }

    public function register()
    {
        $this->app->bind(
            ExceptionHandlerContract::class,
            CustomExceptionHandler::class
        );
    }
}

In the above code, we bind the ExceptionHandleContract interface to the CustomExceptionHandler class through the bind method to use the customExceptionHandler class. Defined exception handler.

1.2.3 Handling exceptions

In the exception handler, we can perform different processing according to the type of exception. Usually, we need to log exceptions for follow-up tracking and return exception information to the user. Here is an example of handling an exception and returning a JSON response:

namespace AppExceptions;

use Exception;
use IlluminateHttpJsonResponse;

class CustomExceptionHandler implements ExceptionHandlerContract
{
    public function report(Exception $exception)
    {
        // 記錄異常到日志中
        Log::error($exception->getMessage());
    }

    public function render($request, Exception $exception)
    {
        // 返回JSON響應(yīng)
        return new JsonResponse([
            'message' => '操作失敗，請(qǐng)稍后再試。',
            'error' => $exception->getMessage(),
        ], 500);
    }
}

In the above code, we use the report method to record the exception to the log and the render method to return the JSON response.

2. Logging

Logging refers to recording the information generated during the operation of the system for subsequent analysis and processing. In Laravel, you can use the Log class provided by the framework to implement the logging function. Let's introduce how to perform logging.

2.1 Log driver

Laravel provides a variety of different log drivers, such as single file driver, daily file driver, syslog driver, database driver, etc. We can configure the log driver used in the config/logging.php file. The following is an example of a configuration file:

return [

    'default' => env('LOG_CHANNEL', 'stack'),

    'channels' => [
        'stack' => [
            'driver' => 'stack',
            'channels' => ['single'],
        ],

        'single' => [
            'driver' => 'single',
            'path' => storage_path('logs/laravel.log'),
            'level' => 'debug',
        ],
    ],

];

In the above code, we use a single file driver to save the logs to storage/logs /laravel.log file.

2.2 Log Level

Laravel’s logs include multiple different levels, such as emergency, alert, critical, error, warning, notice, info, debug, etc. We can configure the log level in the config/logging.php file, the default is debug level. The following is an example of modifying the log level:

return [

    'default' => env('LOG_CHANNEL', 'stack'),

    'channels' => [
        'stack' => [
            'driver' => 'stack',
            'channels' => ['single'],
        ],

        'single' => [
            'driver' => 'single',
            'path' => storage_path('logs/laravel.log'),
            'level' => env('APP_LOG_LEVEL', 'debug'),
        ],
    ],

];

In the above code, we use the env function to obtain the value of the APP_LOG_LEVEL environment variable to set the log level.

2.3 Logging

In Laravel, we can use the Log class to record logs. The following is an example of logging:

use IlluminateSupportFacadesLog;

Log::info('This is an information log.');

In the above code, we use the info method to record an information-level log.

Conclusion

This article introduces the relevant content of exception handling and logging in Laravel development. I hope it will be helpful to Laravel developers. In the actual development process, we should make full use of the powerful functions provided by Laravel to improve development efficiency and ensure the reliability and stability of the system.

The above is the detailed content of Laravel development advice: How to handle exceptions and log records. For more information, please follow other related articles on the PHP Chinese website!