Creating a dateRange Scala, Joda, Java

Question

I have spent hours trying to make this next piece of code work.

import org.joda.time.{DateTime, Period}


def dateRange(from: DateTime, to: DateTime, step: Period): Iterator[DateTime]      =Iterator.iterate(from)(_.plus(step)).takeWhile(!_.isAfter(to))

val range = {
dateRange(new DateTime(2012, 06, 30).minusYears(5), new DateTime(2000, 06, 30),new Period.months(6))
}

I'm trying to set up a date range array that steps through from 2000 to 2012 in 6 month increments. The problem that I am facing is the following error.

Exception in thread "main" java.lang.IllegalArgumentException: No instant converter found for type: scala.Tuple3
at    org.joda.time.convert.ConverterManager.getInstantConverter(ConverterManager.java:165)
at org.joda.time.base.BaseDateTime.<init>(BaseDateTime.java:169)
at org.joda.time.DateTime.<init>(DateTime.java:241)
at tester.MomentumAlgo$class.$init$(MomentumAlgo.scala:154)
at tester.RunMomentumAlgo$$anon$1.<init>(RunMomentumAlgo.scala:86)
at tester.RunMomentumAlgo$.main(RunMomentumAlgo.scala:86)
at tester.RunMomentumAlgo.main(RunMomentumAlgo.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

I seems to be something to do with the last Period.months() part, however I have no idea how to fix it. The Tuple3 error I have no idea about.

If someone can give me a different solution, that would also be great. I want a list of dates from 2000 to 2012, every 6 months.

Any questions welcome. I thought this would be a common piece of code, but there isn't much on the net about it.

Thanks in advance.

Answer 1

Ok, Here is the complete working code.

import org.joda.time.{Period, DateTime}

object runme {

  def main(args:Array[String]) {

  def dateRange(from: DateTime, to: DateTime, step: Period): Iterator[DateTime]
  =Iterator.iterate(from)(_.plus(step)).takeWhile(!_.isAfter(to))

  val range = { dateRange(new DateTime(2000, 06, 30,0,0,0,0).minusYears(5) ,new DateTime(2013, 06, 30,0,0,0,0),new Period(0,6,0,0,0,0,0,0))}

  range.foreach(u => { 
    print(u.getYear)
    print(u.getMonthOfYear)
    println(u.getDayOfMonth)
  })

 }
}

I think my main problem was not having enough numbers after the DateTime() functions (ie the milliseconds etc.) this meant the compiler wasn't receiving all the parameters that it wanted. As mentioned by Alexey Romanov

This then prints the dates for a desired range, and can be used as an iterator.

Hope that helps others.

Thanks @Brian and others for the Help