改进控制器类不存在的异常处理

lang/zh-cn.php

@@ -23,6 +23,7 @@ return [
     'method param miss'         => '方法参数错误',
     'method not exists'         => '方法不存在',
     'module not exists'         => '模块不存在',
+    'controller not exists'     => '控制器不存在',
     'class not exists'          => '类不存在',
     'template not exists'       => '模板文件不存在',
     'illegal controller name'   => '非法的控制器名称',

library/think/App.php

@@ -307,7 +307,9 @@ class App
 
         try {
             $instance = Loader::controller($controller, $config['url_controller_layer'], $config['controller_suffix'], $config['empty_controller']);
-
+            if (is_null($instance)) {
+                throw new HttpException(404, 'controller not exists:' . $controller);
+            }
             // 获取当前操作名
             $action = $actionName . $config['action_suffix'];
             if (!preg_match('/^[A-Za-z](\w)*$/', $action)) {

library/think/Loader.php

@@ -351,8 +351,6 @@ class Loader
             return new $class(Request::instance());
         } elseif ($empty && class_exists($emptyClass = self::parseClass($module, $layer, $empty, $appendSuffix))) {
             return new $emptyClass(Request::instance());
-        } else {
-            throw new ClassNotFoundException('class not exists:' . $class, $class);
         }
     }