yii2 开发api接口时优雅的处理全局异常的方法

# config/web.php
'components' => [
  'errorHandler' => [
    'errorAction' => 'exception/handler'
  ]
]

# controllers/ExceptionController.php
<?php

namespace app\controllers;

use yii\web\Controller;

class ExceptionController extends Controller
{
  /**
   * 为 actionHandler 挂载独立的 action
   * @return array
   */
  public function actions()
  {
    return [
      'handler' => [
        'class' => 'app\actions\ErrorApiAction',
      ]
    ];
  }
}

#actions/ErrorApiAction.php
<?php
/**
 * @author wangzhijian@styd.com
 * @date 2019-5-13 17:20:10
 * Api 全局错误异常处理器
 */

namespace app\actions;

use Yii;
use yii\web\ErrorAction;
use yii\web\Response;

class ErrorApiAction extends ErrorAction
{
  public function run()
  {
    // 根据异常类型设定相应的响应码
    Yii::$app->getResponse()->setStatusCodeByException($this->exception);
    // json 格式返回
    Yii::$app->getResponse()->format = Response::FORMAT_JSON;
    // 返回的内容数据
    return [
      'msg' => $this->exception->getMessage(),
      'err' => $this->exception->getCode()
    ];
  }
}

<?php
/**
 * app 异常基础类
 */

namespace app\exceptions;

class HttpException extends \yii\web\HttpException
{
  public function __construct($message = null, $code = 0, \Exception $previous = null)
  {
    parent::__construct($this->statusCode, $message, $code, $previous);
  }
}

<?php
/**
 * 400 bad request
 */

namespace app\exceptions;

class HttpBadRequestException extends HttpException
{
  public $statusCode = 400;
}

<?php
/**
 * 401 unauthorized
 */

namespace app\exceptions;

class HttpUnauthorizedException extends HttpException
{
  public $statusCode = 401;
}

<?php
/**
 * 403 forbidden
 */

namespace app\exceptions;

class HttpForbiddenException extends HttpException
{
  public $statusCode = 403;
}

<?php
/**
 * 404 not found
 */

namespace app\exceptions;

class HttpNotFoundException extends HttpException
{
  public $statusCode = 404;
}

throw new HttpBadRequestException("具体的非法描述", 4001);
throw new HttpUnauthorizedException("请认证后访问");
throw new HttpForbiddenException("无权访问");
throw new HttpNotFoundException("请求资源不存在");