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我想知道为什么某些字段之间的日期格式不同。我的规则是这样声明的:

@Name("measurement_occupation")
context ParkingSpotOccupation
insert into CreateMeasurement
select
  e.source as source,
  "ParkingSpotOccupation" as type,
  min(e.time) as time,
  {
    "startDate", min(e.time),
    "endDate",  max(e.time),
    "duration", dateDifferenceInSec(max(e.time), min(e.time))
  } as fragments
from
  SmartParkingEvent e
output
  last when terminated;

使用 API 测量结果如下:

{
  "time": "2016-05-30T06:00:00.000+02:00",
  "id": "33200",
  "self": "https://management.post-iot.lu/measurement/measurements/33200",
  "source": {
    "id": "26932",
    "self": "https://management.post-iot.lu/inventory/managedObjects/26932"
  },
  "type": "ParkingSpotOccupation",
  "startDate": {
    "time": 1464580800000,
    "minutes": 0,
    "seconds": 0,
    "hours": 6,
    "month": 4,
    "timezoneOffset": -120,
    "year": 116,
    "day": 1,
    "date": 30
  },
  "duration": 600,
  "endDate": {
    "time": 1464581400000,
    "minutes": 10,
    "seconds": 0,
    "hours": 6,
    "month": 4,
    "timezoneOffset": -120,
    "year": 116,
    "day": 1,
    "date": 30
  }
}

为什么吃时间和 startDate/endDate 呈现不同?更奇怪的是,当显示我的事件处理规则的输出时,它的格式如下:

{ "time": { "date": 30, "day": 1, "hours": 6, "minutes": 0, "month": 4, "seconds": 0, "time": 1464580800000, "timezoneOffset": -120, "year": 116 }, "source": "26932", "fragments": [ "startDate", { "date": 30, "day": 1, "hours": 6, "minutes": 0, "month": 4, "seconds": 0, "time": 1464580800000, "timezoneOffset": -120, "year": 116 }, "endDate", { "date": 30, "day": 1, "hours": 6, "minutes": 10, "month": 4, "seconds": 0, "time": 1464581400000, "timezoneOffset": -120, "year": 116 }, "duration", 600 ], "type": "ParkingSpotOccupation" }

所以每个日期看起来都一样,但当我使用 API 访问测量值时却不同。我希望所有日期都以这种格式存储:“2016-05-30T06:00:00.000+02:00”。我也尝试使用 cast(min(e.time), Date) 但出现错误(无法加载名称为“日期”的 cast 函数中列出的类)。我尝试了 toDate() 函数,但它没有改变任何东西。

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1 回答 1

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问题在于,在 Esper 中,所有日期实际上都是 Java 中的 Date 类,当解析它时,你会得到这个不太好的结构。

最简单的方法是自己将其格式化为 ISO 字符串。您可以使用 Java SimpleDateFormat。在模块中声明它。

create constant variable SimpleDateFormat ISO_FORMATTER = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");

然后就用它

ISO_FORMATTER.format(min(e.time))
ISO_FORMATTER.format(max(e.time))

它返回日期的 ISO 字符串

于 2016-07-06T14:07:13.270 回答