错误内容

java.lang.ClassCastException: com.sun.proxy.$Proxy44 cannot be cast to com.mm.service.imp.RoleServiceImp

测试代码

ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
		RoleServiceImp bean = (RoleServiceImp) context.getBean("roleService");
		Role r = new Role();
		r.setName("超级管理员");
		bean.save(r);

其中继承关系，以及注入为：

@Service(value="roleService")
public class RoleServiceImp implements RoleService {...}

错误原因：通过context.getBean(“xxx”)获取到的对象要转为父接口类型

将代码改成如下即可：

ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
		RoleService bean = (RoleService) context.getBean("roleService");