[QUESTION]在fastjson1升级到fastjson2过程中出现了时间类型不一致如何去适配

在fastjson1中，date时间类型的值在toJSONstring序列化后为时间戳格式，localdatetime序列化为带T的年月日时分秒，但是在升级到fastjson2.0.54的时候，date和localdatetime变成了一致，都是不带T的年月日时分秒，如何让其与fastjson1保持一致呢

Start by comparing the Date and LocalDateTime serialization behavior between fastjson1 and fastjson2.0.54, then review the documented serialization configuration for these types. Done means Date is serialized as a timestamp while LocalDateTime retains the fastjson1 format with a T separator.

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