我所擁有的是我正在撰寫的一段 Scala 代碼中函式的以下輸入資料：
List(
(1,SubScriptionState(CNN,ONLINE,Seq(12))),
(1,SubScriptionState(SKY,ONLINE,Seq(12))),
(1,SubScriptionState(FOX,ONLINE,Seq(12))),
(2,SubScriptionState(CNN,ONLINE,Seq(12))),
(2,SubScriptionState(SKY,ONLINE,Seq(12))),
(2,SubScriptionState(FOX,ONLINE,Seq(12))),
(2,SubScriptionState(CNN,OFFLINE,Seq(13))),
(2,SubScriptionState(SKY,ONLINE,Seq(13))),
(2,SubScriptionState(FOX,ONLINE,Seq(13))),
(3,SubScriptionState(CNN,OFFLINE,Seq(13))),
(3,SubScriptionState(SKY,ONLINE,Seq(13))),
(3,SubScriptionState(FOX,ONLINE,Seq(13)))
)
SubscriptionState這里只是一個案例類：
case class SubscriptionState(channel: Channel, state: ChannelState, subIds: Seq[Long])
我想把它變成這樣：
Map(
1 -> Map(
SubScriptionState(SKY,ONLINE,Seq(12)) -> 1,
SubScriptionState(CNN,ONLINE,Seq(12)) -> 1,
SubScriptionState(FOX,ONLINE,Seq(12)) -> 1),
2 -> Map(
SubScriptionState(SKY,ONLINE,Seq(12,13)) -> 2,
SubScriptionState(CNN,ONLINE,Seq(12)) -> 1,
SubScriptionState(FOX,ONLINE,Seq(12,13)) -> 2,
SubScriptionState(CNN,OFFLINE,Seq(13)) -> 1),
3 -> Map(
SubScriptionState(SKY,ONLINE,Seq(13)) -> 1,
SubScriptionState(FOX,ONLINE,Seq(13)) -> 1,
SubScriptionState(CNN,OFFLINE,Seq(13)) -> 1)
)
我將如何在 Scala 中執行此操作？
uj5u.com熱心網友回復：
這是我解決問題的方法。我認為這可能不是一個完美的解決方案，但它可以如您所愿地作業。
val result: Map[Int, Map[SubscriptionState, Int]] = list
.groupBy(_._1)
.view
.mapValues { statesById =>
statesById
.groupBy { case (_, subscriptionState) => (subscriptionState.channel, subscriptionState.state) }
.map { case (_, groupedStatesById) =>
val subscriptionState = groupedStatesById.head._2 // groupedStatesById should contain at least one element
val allSubIds = groupedStatesById.flatMap(_._2.subIds)
val updatedSubscriptionState = subscriptionState.copy(subIds = allSubIds)
updatedSubscriptionState -> allSubIds.size
}
}.toMap
轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/535445.html
標籤：斯卡拉函数式编程