1、HelloApp
书上是：
BeanFactory factory = new XmlBeanFactory(new FileInputStream("hello.xml"));
应该是：
BeanFactory factory = new XmlBeanFactory(new FileSystemResource("hello.xml"));
2、KnightApp
在实现了XML中Minstrel的interceptor后，
需要把
KnightOfTheRoundTable knight = (KnightOfTheRoundTable) factory.getBean("knight");
改成：
Knight knight = (Knight) factory.getBean("knight");
否则会报：
Exception in thread "main" java.lang.ClassCastException: $Proxy0