在 Symfony2 中捕获数据库异常

Catching database exceptions in Symfony2

我遇到了一个无法缩小范围的随机问题。有时,我会在 Symfony2 应用程序中遇到以下错误:

Uncaught Exception: An exception occured in driver: SQLSTATE[08004] [1040] Too many connections {"type":1,"file":"/var/www/symfony/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php","line":115,"level":30709

我想设置一个应用程序范围的侦听器来捕获 PDOException 并记录一些信息。我怎样才能连接到 Symfony 只捕获 PDOException?

像这样定义服务:

<service id="app.listener.kernel.exception"
                 class="MyAppBundle\Listener\KernelExceptionListener">
            <tag name="kernel.event_listener" event="kernel.exception" method="onKernelException"/>
            <argument type="service" id="logger"/>
</service>

还有一个 class 这样的:

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;

class KernelExceptionListener
{
    private $logger;

    public function __construct(Monolog\Logger $logger)
    {
        $this->logger = $logger;
    }

    public function onKernelException(GetResponseForExceptionEvent $event)
    {
        // Here check the exception
        //$event->getException()
    }
}

您需要创建自定义异常侦听器。它将侦听所有异常,但您将在其中指定类型检查。

在您的 services.yml 中您需要指定侦听器:

kernel.listener.your_pdo_listener:
        class: Acme\AppBundle\EventListener\YourExceptionListener
        tags:
           - { name: kernel.event_listener, event: kernel.exception, method: onPdoException }

现在你需要创建这个 class:

你的异常监听器:

use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
class YourExceptionListener
{
     public function onPdoException(GetResponseForExceptionEvent $event)
     {
          $exception = $event->getException();

          if ($exception instanceof PDOException) {
              //now you can do whatever you want with this exception
          }
     }
}

检查文档how to create event listener