添加NotFound异常类

library/think/exception/NotFoundException.php

@@ -0,0 +1,27 @@
+<?php
+// +----------------------------------------------------------------------
+// | ThinkPHP [ WE CAN DO IT JUST THINK ]
+// +----------------------------------------------------------------------
+// | Copyright (c) 2006~2016 http://thinkphp.cn All rights reserved.
+// +----------------------------------------------------------------------
+// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
+// +----------------------------------------------------------------------
+// | Author: 麦当苗儿 <zuojiazi@vip.qq.com> <http://zjzit.cn>
+// +----------------------------------------------------------------------
+
+namespace think\exception;
+
+use think\Exception;
+
+/**
+ * Database相关异常处理类
+ */
+class NotFoundException extends Exception 
+{
+    /**
+     * 系统异常后发送给客户端的HTTP Status
+     * @var integer
+     */
+    protected $httpStatus = 404;
+    
+}