请教：Spring @Autowired注解实现了接口的成员变量时失败

场景：
1、类A中有成员变量类B,类B使用@Autowired注解的方式注入A中。
2、类B实现了接口IB.

问题：
启动时报错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'a':
Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException:
Could not autowire field: com.siqisoft.test.B com.siqisoft.test.A.b;
nested exception is java.lang.IllegalArgumentException:
Can not set com.siqisoft.test.B field com.siqisoft.test.A.b to $Proxy23

疑问：
为什么实现了接口的B不能被注入到A中呢？

类A:

package com.siqisoft.test;



import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Component;



@Component

public class A {

	@Autowired

	B b;

}

类B:

package com.siqisoft.test;



import org.springframework.stereotype.Component;



@Component

public class B {

	 public  void  BMethod(){};

}

B实现的接口

package com.siqisoft.test;



public abstract interface IB   {

	

}