scala 访问文件系统

import java.io.Fileobject day20 {  def main(args: Array[String]): Unit = {    for(d<-subDir1(new File("/java/jdk1.7.0_79")))      println(d)  }  //访问子目录  def subDir(dir:File):Iterator[File] = {    val children = dir.listFiles().filter { _.isDirectory() }    children.toIterator ++ children.toIterator.flatMap { subDir _}  }  //访问子目录和文件  def subDir1(dir:File):Iterator[File]={    val dirs = dir.listFiles().filter { _.isDirectory()}    val files = dir.listFiles().filter { _.isFile() }    files.toIterator ++ dirs.toIterator.flatMap { subDir1 _ }  }}