Spring - 作为CGLIB代理的Classcast异常不能被强制

这是让我疯狂的情景。我有一个具有查找方法的类 - createOther（） createOther应该创建一个Other类型的对象。其他实现OtherInterface，另外还有一个标记为@Async的方法doSomething 由于Other实现了OtherInterface，Spring给了我一个我不能作为Other转换的JDK代理。 Spring文档建议使用<aop:config proxy-target-class="true"> - 但我是新手，使用它似乎没有帮助。问题：我如何告诉Spring我需要一个针对Other类的CGLib代理？下面的代码失败，带有classcastexception。

    Exception in thread "main" java.lang.ClassCastException: $Proxy4 cannot be cast to scratch.Other
at scratch.App$$EnhancerByCGLIB$$82d16307.createOther(<generated>)
at scratch.App.main(App.java:19)

App.java：

public class App {
public Other createOther() {
    throw new UnsupportedOperationException();
}

public static void main(final String[] args) {

    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("appcontext.xml");
    App app = (App) context.getBean("app");
    Other oth = app.createOther();
    oth.doSomething();
    System.out.println("Other created");
}

} ** Other.java **

public interface OtherInterface {

}

class Other implements OtherInterface {

@Async
public void doSomething() {
    System.out.println("did something");
}
}

** appcontext.xml **

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:task="http://www.springframework.org/schema/task"
xmlns:aop="http://www.springframework.org/schema/aop" 
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<aop:config proxy-target-class="true"></aop:config>
<bean name="app" class="scratch.App">
    <lookup-method bean="otherBean" name="createOther" />
</bean>

<bean name="otherBean" class="scratch.Other" scope="prototype">
</bean>
<task:executor id="workflowExecutorSvcPool" pool-size="5-50"
    queue-capacity="1000" keep-alive="60" />
<task:annotation-driven executor="workflowExecutorSvcPool" />

</beans>