在Scala/Spark中将纪元转换为日期时间

问题描述：

我正在使用:

def strToTime(x: String):Long = { DateTimeFormat.
    forPattern("YYYY-MM-dd HH:mm:ss").parseDateTime(x).getMillis()/1000 }

获得像这样的Long列表:

to get a list of Long like this :

.map( p=> List( strToTime(p(0) ) ) )

我的问题是-向后上交的最简单方法是什么? 像这样:

my question is - what is the easiest way to turn in backwards? something like:

def timeToStr(x: Long):String = { x*1000L.toDateTime}

我可以在上面的列表(长)上使用的

that I could use on the above List(Long)

I have read Convert seconds since epoch to joda DateTime in Scala but can't apply it successfully

答

您有一个优先级问题-在应用*之前将.toDateTime应用于1000L.用括号括起来以清楚显示呼叫顺序:

You have a precedence problem - .toDateTime is being applied to 1000L before * is applied. Bracket the operations to make the call order clear:

def timeToStr(x: Long): String = { (x*1000L).toDateTime }