優(yōu)勢(shì)：

1.異常處理通常是防止未知錯(cuò)誤產(chǎn)生所采取的處理措施。異常處理的好處是不用再絞盡腦汁去考慮各種錯(cuò)誤随夸，這為處理某一類(lèi)錯(cuò)誤提供了一個(gè)很有效的方法，使編程效率大大提高。
2.自定義拋出異常的好處绷跑，避免if else嵌套，增強(qiáng)代碼可讀性凡资，返回給前端一個(gè)簡(jiǎn)化的json信息砸捏，進(jìn)行相應(yīng)處理。

TP6實(shí)例
在app目錄下新建lib\exception文件夾
在文件夾下新建ExceptionHandle.php隙赁，BaseException.php

ExceptionHandle.php代碼垦藏，重寫(xiě)render

<?php
namespace app\lib\exception;

use think\Exception;
use think\exception\Handle;
use think\Log;
use think\Response;
use Throwable;

/**
 * 應(yīng)用異常處理類(lèi)
 */
class ExceptionHandle extends Handle
{
    public $httpStatus =500 ;
    private $code;
    private $msg;
    private $errorCode;

    public function render($request, Throwable $e): Response
    {
        if($e instanceof BaseException){
            $this->code = $e->code;
            $this->msg = $e->msg;
            $this->errorCode = $e->errorCode;
        }else{
            if(env('APP_DEBUG', '0')){
                return parent::render($request, $e);
            }else{
                $this->code =500;
                $this->msg='服務(wù)器錯(cuò)誤,請(qǐng)聯(lián)系客服或者稍后再試';
                $this->errorCode=999;
                $this->recordErrorLog($e);
            }
        }
        $result = [
            'error_code' => $this->errorCode,
            'msg'  => $this->msg,
            'request_url' => request()->url()
        ];

        return json($result, $this->code);
    }
    //記錄日志
    public function recordErrorLog(Exception $e){
        Log::record($e->getMessage(),'error');
    }
}

BaseException.php

<?php
namespace app\lib\exception;


use think\Exception;
use Throwable;

class BaseException extends Exception
{
    public $code = 400;
    public $msg = 'invalid parameters';
    public $errorCode = 999;
    public $paramsEnum = [];
    public $shouldToClient = true;

    public function __construct($params=[], $type=0)
    {
        if(!is_array($params)){
            return;
        }
        if(array_key_exists('code',$params)){
            $this->code = $params['code'];
        }
        if(array_key_exists('msg',$params)){
            $this->msg = $params['msg'];
        }
        if(array_key_exists('errorCode',$params)){
            $this->errorCode = $params['errorCode'];
        }

        if( $type ){
            $params = $this->paramsEnum[ $type ];
            $this->errorCode = $params['error_code'];
            $this->msg = $params['msg'];
        }
    }
}

使用

1、在app目錄下的provider.php文件中綁定異常處理類(lèi)伞访，
坑1：如果按照開(kāi)發(fā)手冊(cè)來(lái)寫(xiě)的話(huà)掂骏，總是不會(huì)走自定義異常，報(bào)錯(cuò)500
解決方法如下代碼

<?php
use app\lib\exception\ExceptionHandle;
use app\Request;

// 容器Provider定義文件
return [
    'think\Request'          => Request::class,
    'think\exception\Handle' => ExceptionHandle::class,
];

2厚掷、在app\lib\exception下新建異常處理類(lèi)弟灼，例：
新建ActivityException.php代碼如下

<?php
namespace app\lib\exception;

class ActivityException extends BaseException{
    public $code = 400;
    public $msg = 'activity is error';
    public $errorCode = 10700; // 10700-10799

    public $paramsEnum = [
        1 => ['error_code'=>10701, 'msg'=>'活動(dòng)添加失敗，請(qǐng)重試~'],
        2 => ['error_code'=>10702, 'msg'=>'活動(dòng)添加失敗冒黑，請(qǐng)重試'],
        3 => ['error_code'=>10703, 'msg'=>'票據(jù)規(guī)格添加田绑，請(qǐng)重試'],
        4 => ['error_code'=>10704, 'msg'=>'活動(dòng)不存在'],
        5 => ['error_code'=>10705, 'msg'=>'不可跨賬號(hào)操作~'],
        6 => ['error_code'=>10706, 'msg'=>'活動(dòng)不存在或已下架~'],
        7 => ['error_code'=>10707, 'msg'=>'票據(jù)不存在~'],
        8 => ['error_code'=>10708, 'msg'=>'該票據(jù)已售罄，請(qǐng)更換其他規(guī)格~'],
        9 => ['error_code'=>10709, 'msg'=>'活動(dòng)名額已滿(mǎn)薛闪，親下次早來(lái)哦~'],
        10 => ['error_code'=>10710, 'msg'=>'下單失敗辛馆，請(qǐng)重試~']
    ];

    public function __construct($params=[],$type=0)
    {
        parent::__construct($params, $type);
    }
}

3、使用時(shí)引入ActivityException豁延，可使用定義好的拋出異常類(lèi)型昙篙，也可以自定義拋出異常信息

throw new ActivityException([],1);

結(jié)果

返回Json信息