Laravel默认的会把没有捕获的异常写到日志的。但是写的日志信息特别不详细，如果异常产生在底层的类里面。看日志堆栈还是不知道这个异常日志是哪里引起的。
下面是一个底层响应类抛出的异常日志如下：
[2019-10-18 09:51:46] local.ERROR: The Response content must be a string or object implementing __toString(), "boolean" given. {"exception":"[object] (UnexpectedValueException(code: 0): The Response content must be a string or object implementing __toString(), \"boolean\" given. at D:\\WWW\\bohua\\vendor\\symfony\\http-foundation\\Response.php:399)
[stacktrace]
#0 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Http\\Response.php(45): Symfony\\Component\\HttpFoundation\\Response->setContent(true)
#1 D:\\WWW\\bohua\\vendor\\symfony\\http-foundation\\Response.php(206): Illuminate\\Http\\Response->setContent(true)
#2 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(724): Symfony\\Component\\HttpFoundation\\Response->__construct(true)
#3 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(698): Illuminate\\Routing\\Router::toResponse(Object(Illuminate\\Http\\Request), true)
#4 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(658): Illuminate\\Routing\\Router->prepareResponse(Object(Illuminate\\Http\\Request), true)
#5 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(30): Illuminate\\Routing\\Router->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#6 D:\\WWW\\bohua\\app\\Http\\Middleware\\AuthUser.php(39): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#7 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): App\\Http\\Middleware\\AuthUser->handle(Object(Illuminate\\Http\\Request), Object(Closure), 'check')
#8 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#9 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Middleware\\SubstituteBindings.php(41): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#10 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): Illuminate\\Routing\\Middleware\\SubstituteBindings->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#11 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#12 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(102): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#13 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(660): Illuminate\\Pipeline\\Pipeline->then(Object(Closure))
#14 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(635): Illuminate\\Routing\\Router->runRouteWithinStack(Object(Illuminate\\Routing\\Route), Object(Illuminate\\Http\\Request))
#15 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(601): Illuminate\\Routing\\Router->runRoute(Object(Illuminate\\Http\\Request), Object(Illuminate\\Routing\\Route))
#16 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Router.php(590): Illuminate\\Routing\\Router->dispatchToRoute(Object(Illuminate\\Http\\Request))
#17 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Kernel.php(176): Illuminate\\Routing\\Router->dispatch(Object(Illuminate\\Http\\Request))
#18 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(30): Illuminate\\Foundation\\Http\\Kernel->Illuminate\\Foundation\\Http\\{closure}(Object(Illuminate\\Http\\Request))
#19 D:\\WWW\\bohua\\vendor\\fideloper\\proxy\\src\\TrustProxies.php(56): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#20 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): Fideloper\\Proxy\\TrustProxies->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#21 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#22 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest.php(30): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#23 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#24 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#25 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest.php(30): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#26 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#27 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#28 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize.php(27): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#29 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#30 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#31 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Middleware\\CheckForMaintenanceMode.php(46): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#32 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(149): Illuminate\\Foundation\\Http\\Middleware\\CheckForMaintenanceMode->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#33 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Routing\\Pipeline.php(53): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#34 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Pipeline\\Pipeline.php(102): Illuminate\\Routing\\Pipeline->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#35 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Kernel.php(151): Illuminate\\Pipeline\\Pipeline->then(Object(Closure))
#36 D:\\WWW\\bohua\\vendor\\laravel\\framework\\src\\Illuminate\\Foundation\\Http\\Kernel.php(116): Illuminate\\Foundation\\Http\\Kernel->sendRequestThroughRouter(Object(Illuminate\\Http\\Request))
#37 D:\\WWW\\bohua\\public\\index.php(58): Illuminate\\Foundation\\Http\\Kernel->handle(Object(Illuminate\\Http\\Request))
#38 {main}
"}
从这个日志中，我不知道是哪个请求引起，哪个控制器，或者哪个命令行引起的了？
这个引起的原因很简单就是哪个控制器中 return true 导致：Ｔhe Response content must be a string or object implementing __toString(), 响应的内容必须是字符串或者实现了__toString方法的对象。
最后在AppServiceProvider类的boot方法中，把请求写入日志，才找到引起异常的原因。实现如下：
if (env("APP_DEBUG")) {
/**
* debug 默认记录请求记录
*/
if (app()->runningInConsole() == false) {
$requestData = \Request::input();
unset($requestData['pathinfo']);
\Log::info(\Request::ip() . ' ' . \Request::method() . ' ' . \Request::getHttpHost() . \Request::getRequestUri() . ' ' . json_encode($requestData, JSON_UNESCAPED_UNICODE));
}
}