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));
}
}