try catch的简单使用
```
try {
    CatalogService::test();
} catch (Exception $e) {
    return $this->jsonError($e->getMessage());
}    
CatalogService
public static function test(){
    throw new Exception("出现错误");
}
```
try catch的简单使用
```
try {
    CatalogService::test();
} catch (Exception $e) {
    return $this->jsonError($e->getMessage());
}    
CatalogService
public static function test(){
    throw new Exception("出现错误");
}
```