laravel异常处理

1.场景：正常PC访问时，如点击商品时，此时商品刚好下架，那么要如何给出相应的提示?

php artisan make:exception InvalidRequestException

从5.5版本后，支持在异常类中定义render()方法.异常触发时会自动调用render（）；

namespace AppExceptions;

use Exception;
use IlluminateHttpRequest;

class InvalidRequestException extends Exception
{
    public function __construct(string $message = "", int $code = 400)
    {
        parent::__construct($message, $code);
    }

    public function render(Request $request)
    {
        if ($request->expectsJson()) {
            // json() 方法第二个参数就是 Http 返回码
            return response()->json(['msg' => $this->message], $this->code);
        }

        return view('pages.error', ['msg' => $this->message]);
    }
}

2.再在view/pages/error.blade.php里做好模板

@extends('layouts.app')
@section('title', '错误')

@section('content')
<div class="card">
    <div class="card-header">错误</div>
    <div class="card-body text-center">
        <h1>{{ $msg }}</h1>
        <a class="btn btn-primary" href="{{ route('root') }}">返回首页</a>
    </div>
</div>
@endsection

3.当出现异常时，laravel默认会写到日志里，那么如何关掉因这个类而产生的日志呢

app/Exceptions/Handler.php

    protected $dontReport = [
        InvalidRequestException::class,
    ];

4.还有一种异常，即要给个信息到用户看，也在存个信息到日志，而这俩错误信息是不同的内容时：

　　php artisan make:exception InternalException

namespace AppExceptions;

use Exception;
use IlluminateHttpRequest;

class InternalException extends Exception
{
    protected $msgForUser;

    public function __construct(string $message, string $msgForUser = '系统内部错误', int $code = 500)
    {
        parent::__construct($message, $code); //这里会自动存错误到日志
        $this->msgForUser = $msgForUser;
    }

    public function render(Request $request)
    {
        if ($request->expectsJson()) {  //这里给上面指定的错误信息给到用户
            return response()->json(['msg' => $this->msgForUser], $this->code);
        }

        return view('pages.error', ['msg' => $this->msgForUser]);
    }
}

 在控制器中就直接这么用

        if (!$product->on_sale) {
            throw new InvalidRequestException('商品未上架');
        }