Scala根据开始时间和结束时间，把这个时间段所有的时间都列出来

   import java.text.SimpleDateFormat

   import java.util.Calendar

   import scala.collection.mutable.ArrayBuffer

    val startTime = "2017-12-01"

    val endTime = "2017-12-10"

   val dateFormat = new SimpleDateFormat("yyyy-MM-dd")

    val dateFiled = Calendar.DAY_OF_MONTH

    var beginDate = dateFormat.parse(startTime)

    val endDate = dateFormat.parse(endTime)

    val calendar = Calendar.getInstance()

    calendar.setTime(beginDate)

    val dateArray: ArrayBuffer[String] = ArrayBuffer()

    while (beginDate.compareTo(endDate) <= 0) {

      dateArray += dateFormat.format(beginDate)

      calendar.add(dateFiled, 1)

      beginDate = calendar.getTime

    }

    dateArray.toList       // List(2017-12-01, 2017-12-02, 2017-12-03, 2017-12-04, 2017-12-05, 2017-12-06, 2017-12-07, 2017-12-08, 2017-12-09, 2017-12-10)