gson反序列化成list時，報錯

我使用gson反序列化成list<CartRedisDto>時，報錯java.lang.IllegalStateException: Expected BEGIN_ARRAY but was STRING

我CartRedisDto對象是

@Data
public class CartRedisDto {

    private String openId;
    private String productId;
    private Integer quantity;
    private Date createTime;
    private Date updateTime;

}

我使用gson反序列化的代碼如下

        String cartRedisString = jedis.get(KEY);
        Type type = new TypeToken<List<CartRedisDto>>() {}.getType();
        List<CartRedisDto> oldCartRedisDtoList = gson.fromJson(gson.toJson(cartRedisString), type);

執(zhí)行的時候報錯
java.lang.IllegalStateException: Expected BEGIN_ARRAY but was STRING at line 1 column 2 path $
請問這個是什么原因

我反序列化的json如下

[
    {
        "openId": "123456",
        "productId": "111111",
        "quantity": 5,
        "createTime": "Nov 8, 2017 11:22:52 PM",
        "updateTime": "Nov 8, 2017 11:22:52 PM"
    }
]