springmvc+mybatis整合 MapperScannerConfigurer配置出错

配置如下：

问题：如果配置了    <property name="sqlSessionFactoryBeanName" value="wechatSqlSessionFactory" />，启动的时候报错如下：Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.mybatis.spring.mapper.MapperScannerConfigurer#0' defined in class path resource [spring/applicationContext-persistence.xml]: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'sqlSessionFactoryBeanName' of bean class [org.mybatis.spring.mapper.MapperScannerConfigurer]: Bean property 'sqlSessionFactoryBeanName' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?

如果不配置sqlSessionFactoryBeanName，则可以正常启动，正常操作数据库。

求大神解释一下到底是什么问题，怎么解决这种问题。希望能得到帮助。谢谢