Scala删除所有文件，但不删除目录

Question

I have a directory and subfolder in it. The directory contains 5 file and one subdirectory. I need to empty the subfolder and delete 3 files out of 5.

Currently I am using below code which is deleting the file but sub folder is not getting empty. Please suggest

  Files.deleteIfExists(Paths.get("src/main/tempDir/doc-topics-new.txt"))
  Files.deleteIfExists(Paths.get("src/main/tempDir/new_corpus.mallet"))
  Files.deleteIfExists(Paths.get("src/main/tempDir/corpus.mallet"))
  Files.deleteIfExists(Paths.get("src/main/tempDir/sub_directory/*"))

Answer 1

better-files supports deleting all children in directory with file.clear() whilst files could be deleted with file.delete() . Here is a working example

import better.files._

object Hello extends App {
    val subdirectory = file"/path/to/subdirectory"
    subDirectory.clear()

    val file1 = file"/path/to/file1.txt"
    file1.delete()
}

where we need the following dependency

libraryDependencies += "com.github.pathikrit" %% "better-files" % "3.8.0"

Answer 2

You can delete the files from the subdirectory (but not the directory itself) like this:

def deleteOnlyFiles(file: File): Unit = {
  if (file.isDirectory) {
    file.listFiles.foreach(deleteOnlyFiles)
  } else {
     if (file.exists && !file.delete) {
       throw new Exception(s"Unable to delete ${file.getAbsolutePath}")
     }
  }
}