DefaultSerializer requires a Serializable payload but received an object of type [model.Admin]

一.问题描述:
  在用redis做二级缓存时，出现如下异常

DefaultSerializer requires a Serializable payload but received an object of type [model.Admin]

二.问题分析:
  要缓存的 Java 对象必须实现 Serializable 接口，因为 Spring 会将对象先序列化再存入 Redis

三.解决方法:
 将缓存实体类继承 Serializable

public class Admin implements Serializable