SpringBoot在REST WS中的日期值发生莫名其妙的变化

Question

考虑以下我使用Postman提取或放置一些值的json正文：

{
  "server":
    {
      "address":"ITEM-EX30099",
      "port":10500
    },
  "instance":{
    "instance-name":"instance",
    "instance-number":100252,
    "date":"20190429"
  }
}

当我调试代码时，我注意到我放在上述json正文中的所有信息都没有改变，除了日期值（从20190429到Mon Dec 31 01:00:00 CET 2018莫名其妙地变化）

有人知道我为什么会有这个问题吗？

这是控制器的方法：

@RequestMapping(value = "/{instanceName}/{action}", method = RequestMethod.PUT, consumes = "application/json")
public ResponseEntity putInstanceStatus(@PathVariable(name = "action") String action, @RequestHeader(HeaderFilter.USER_KEY) String username, @RequestHeader(HeaderFilter.PASSWORD_KEY) String password,
                                        @RequestBody ServerInstanceRequestWrapper serverInstanceRequestWrapper)
{
    InstanceActionResponse instanceActionResponse = instanceService.putInstanceStatus(action, username, password, serverInstanceRequestWrapper.getServer(), serverInstanceRequestWrapper.getInstance().getInstanceName(), String.valueOf(serverInstanceRequestWrapper.getInstance().getInstanceNumber()), serverInstanceRequestWrapper.getInstance().getDate().toString());
    return ResponseEntity.ok(instanceActionResponse);
}

在实例类中，这是我声明日期属性的方式：

@JsonProperty("date")
@JsonFormat(pattern = "YYYYMMdd")
private Date date;