org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deseria

org.springframework.http.converter.HttpMessageNotReadableException:

JSON parse error: Cannot deserialize value of type `java.util.Date` from String "NULL": not a valid representation

(error: Failed to parse Date value 'NULL': Unparseable date: "NULL");

nested exception is com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `java.util.Date` from String "NULL": not a valid representation (error: Failed to parse Date value 'NULL': Unparseable date: "NULL")
 at [Source: (PushbackInputStream); line: 16, column: 14] (through reference chain: com.starsaiot.battery.entity.PledgeOrder["payTime"])

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在前后端分离的项目里遇到了这个问题

前端输入的数据是 "payTime": "NULL",
"tradeNum": "null",
  "updateTime": "2021-08-17 16:39:50",
  "updated": "null",

控制台报这个错

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出错原因：payTime的类型不对，这个大写的NULL是我从数据库里复制的数据，每太注意就放进去了，应该要和下面的null保持一致。