shiro的session信息放redis反序列化异常解决

org.apache.catalina.core.StandardWrapperValve.invoke 鍦ㄨ矾寰勪负/traffic-web鐨勪笂涓嬫枃涓紝Servlet[spring2]鐨凷ervlet.service锛堬級寮曞彂浜嗗叿鏈夋牴鏈師鍥犵殑寮傚父Filtered request failed.
    com.fasterxml.jackson.databind.JsonMappingException: Problem deserializing 'setterless' property ("realmNames"): no way to handle typed deser with setterless yet (through reference chain: org.apache.shiro.subject.SimplePrincipalCollection["realmNames"])
        at com.fasterxml.jackson.databind.deser.impl.SetterlessProperty.deserializeAndSet(SetterlessProperty.java:102)
        at com.fasterxml.jackson.databind.deser.impl.BeanPropertyMap.findDeserializeAndSet(BeanPropertyMap.java:285)
        at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:248)
        at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:169)
        at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:144)
        at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedForId(AsPropertyTypeDeserializer.java:124)
        at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:95)
        at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromAny(AsPropertyTypeDeserializer.java:167)
        at com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer$Vanilla.deserializeWithType(UntypedObjectDeserializer.java:494)
        at com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer.deserialize(TypeWrappedDeserializer.java:42)
        at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3560)
        at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2709)

public Set<String> getRealmNames() {
    if (realmPrincipals == null) {
        return null;
    } else {
        return realmPrincipals.keySet();
    }
}

/**
     * retemplate相关配置
     * 序列化配置
     */
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(factory);
        template.setKeySerializer(new StringRedisSerializer());
        template.setHashKeySerializer(new StringRedisSerializer());
        template.afterPropertiesSet();
        return template;
    }