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February 4, 2020 12:23
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Get a list of files that are in a directory and subdirectories
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| def recursiveListFiles(f: File): ArraySeq[File] = { | |
| val these = f.listFiles | |
| ArraySeq.from(these ++ these.filter(_.isDirectory).flatMap(recursiveListFiles)) | |
| } | |
| /// | |
| import java.io.File | |
| def getListOfFiles(dir: String): List[File] = { | |
| def go(dir: File): List[File] = dir match { | |
| case d if d.exists && d.isDirectory && d.canRead=> | |
| val files = d.listFiles.filter(a => a.canRead && a.isFile).toList | |
| val dirs = dir.listFiles.filter(_.isDirectory).toList | |
| files ::: dirs.foldLeft(List.empty[File])(_ ::: go(_)) | |
| case _ => List.empty[File] | |
| } | |
| go(new File(dir)) | |
| } | |
| // using cats | |
| import java.io.File | |
| import cats.effect.IO | |
| def getListOfFiles(dir: String): IO[List[File]] = { | |
| def go(dir: File): List[File] = dir match { | |
| case d if d.exists && d.isDirectory => | |
| if (d.canRead) { | |
| val files = d.listFiles.filter(_.isFile).toList | |
| val dirs = dir.listFiles.filter(_.isDirectory).toList | |
| files ::: dirs.foldLeft(List.empty[File])(_ ::: go(_)) | |
| } else throw new IOException(s"Error opening directory '$d': Permission denied") | |
| case _ => List.empty[File] | |
| } | |
| IO.fromTry(Try(go(new File(dir)))) | |
| } |
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