不并行打印文件内容

Question

我试图打印出文件的内容，但每次我运行这段代码什么都没有 return。我知道文件存在（因为第 4 行）并且有内容。为什么此代码 return 没有结果？

 import scala.xml._
 import collection.mutable.HashMap
 import java.nio.file.{Paths, Files}

 val noDupFile="nodup_steam_out.txt"
 println(Files.exists(Paths.get(noDupFile))) //returns true

object HelloWorld {
    def main(args: Array[String]) {

    io.Source.fromFile(noDupFile).getLines().toStream.par.foreach((res:String)=>{
        println(res)
    })

编辑：提出答案后，我更新了我的代码以采纳建议：

 import scala.xml._
 import collection.mutable.HashMap
 import java.nio.file.{Paths, Files}

 val api="BLAH"

object HelloWorld {
    def main(args: Array[String]) {
    val noDupFile="nodup_steam_out.txt"
    println(Files.exists(Paths.get(noDupFile))) //returns true
    io.Source.fromFile(noDupFile).getLines().toStream.par.foreach((res:String)=>{
        /*
        val url=("http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key="+api+"&steamids="+res+"&format=xml")
        //http://api.steampowered.com/ISteamUser/GetFriendList/v0001/?key=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX&steamid=76561197960435530&relationship=friend
        //http://api.steampowered.com/IPlayerService/GetOwnedGames/v0001/?key=XXXXXXXXXXXXXXXXX&steamid=76561197960434622&format=json
        //http://api.steampowered.com/IPlayerService/GetRecentlyPlayedGames/v0001/?key=XXXXXXXXXXXXXXXXX&steamid=76561197960434622&format=json
        //http://api.steampowered.com/ISteamUser/GetPlayerBans/v1/?key=XXXXXXXXXXXXXXXXX&steamids=XXXXXXXX,YYYYY
        val str = scala.io.Source.fromURL(url.toString,"utf-8").mkString
        val x=xml.XML.loadString(str)       
         val allNodes = x \ "response" \ "players" \ "player" flatMap(_.child) filter(!_.isAtom)
        allNodes.foreach(n => {
            print(s"${n.label}: ${n.text},")
        })
        */
        println(res)
    })
}}

Answer 1

您的示例缺少对象 HelloWorld 的右大括号。

此外，您需要将 val 放入对象中。如果您尝试 scalac 您的文件，它应该会报错。工作代码：

import scala.xml._
import collection.mutable.HashMap
import java.nio.file.{Paths, Files}

object HelloWorld {

val noDupFile="nodup_steam_out.txt"
println(Files.exists(Paths.get(noDupFile))) //returns true
    def main(args: Array[String]) {

    io.Source.fromFile(noDupFile).getLines().toStream.par.foreach((res:String)=>{
        println(res)
    })  
}}

编辑代码的正确版本：

import scala.xml._
 import collection.mutable.HashMap
 import java.nio.file.{Paths, Files}

    object HelloWorld {
        def main(args: Array[String]) {
            val api="BLAH"
            val noDupFile="nodup_steam_out.txt"
            println(Files.exists(Paths.get(noDupFile))) //returns true
            io.Source.fromFile(noDupFile).getLines().toStream.par.foreach((res:String)=>{
                println(res)
            })
    }}

不并行打印文件内容

not printing file contents in parallel

scala

file-io

fileinputstream