[源码地址](https://github.com/fuzhengwei/itstack-demo-design/blob/master/itstack-demo-design-6-00/src/main/java/org/itstack/demo/design/service/OrderService.java) 将 ```java private Logger logger = LoggerFactory.getLogger(POPOrderService.class); ``` 修改为 ```java private Logger logger = LoggerFactory.getLogger(OrderService.class ); ``` 纸质书上也存在这个勘误