Delete all files in directory but not directory - one liner solution

Question

I want to delete all files inside ABC directory   When I tried with FileUtils deleteDirectory new File  C  test ABC      it also deletes folder ABC   Is there a one liner solution where I can delete files inside directory but not directory

User · Answer

Another Java 8 Stream solution to delete all the content of a folder, sub directories included, but not the folder itself.

Usage:

Path folder = Paths.get("/tmp/folder");
CleanFolder.clean(folder);

and the code:

public interface CleanFolder {
    static void clean(Path folder) throws IOException {

        Function<Path, Stream<Path>> walk = p -> {
            try { return Files.walk(p);
        } catch (IOException e) {
            return Stream.empty();
        }};

        Consumer<Path> delete = p -> {
            try {
                Files.delete(p);
            } catch (IOException e) {
            }
        };

        Files.list(folder)
            .flatMap(walk)
            .sorted(Comparator.reverseOrder())
            .forEach(delete);
    }
}

The problem with every stream solution involving Files.walk or Files.delete is that these methods throws IOException which are a pain to handle in streams.

I tried to create a solution which is more concise as possible.

User · Answer

Or to use this in Java 8   try     Files newDirectoryStream  directory   forEach  file - gt        try   Files delete  file          catch   IOException e     throw new UncheckedIOException e              catch   IOException e       e printStackTrace        It s a pity the exception handling is so bulky  otherwise it would be a one-liner

User · Answer

For deleting all files from directory say  C  Example   File file   new File  C   Example          String   myFiles      if  file isDirectory          myFiles   file list        for  int i   0  i  lt  myFiles length  i              File myFile   new File file  myFiles i             myFile delete

User · Answer

rm -rf was much more performant than FileUtils cleanDirectory   Not a one-liner solution but after extensive benchmarking  we found that using rm -rf was multiple times faster than using FileUtils cleanDirectory    Of course  if you have a small or simple directory  it won t matter but in our case we had multiple gigabytes and deeply nested sub directories where it would take over 10 minutes with FileUtils cleanDirectory and only 1 minute with rm -rf   Here s our rough Java implementation to do that       Delete directory given and all subdirectories and files  i e  recursively      static public boolean clearDirectory  File file   throws IOException  InterruptedException        if   file exists                String deleteCommand    rm -rf     file getAbsolutePath            Runtime runtime   Runtime getRuntime             Process process   runtime exec  deleteCommand            process waitFor             file mkdirs       Since we only want to clear the directory and not delete it  we need to re-create the directory           return true             return false       Worth trying if you re dealing with large or complex directories

User · Answer

package com  import java io File  public class Delete       public static void main String   args             String files           File file   new File  D   del  yc  gh            File   listOfFiles   file listFiles             for  int i   0  i  lt  listOfFiles length  i                           if  listOfFiles i  isFile                                   files   listOfFiles i  getName                    System out println files                   if  files equalsIgnoreCase  Scan pdf                                          boolean issuccess new File listOfFiles i  toString    delete                        System err println  Deletion Success   issuccess                                                       If you want to delete all files remove   if  files equalsIgnoreCase  Scan pdf      statement it will work

User · Answer

Do you mean like   for File file  dir listFiles         if   file isDirectory             file delete      This will only delete files  not directories

User · Answer

import org apache commons io FileUtils   FileUtils cleanDirectory directory      There is this method available in the same file  This will also recursively deletes all sub-folders and files under them   Docs  org apache commons io FileUtils cleanDirectory

User · Answer

Peter Lawrey s answer is great because it is simple and not depending on anything special  and it s the way you should do it  If you need something that removes subdirectories and their contents as well  use recursion   void purgeDirectory File dir        for  File file  dir listFiles              if  file isDirectory                purgeDirectory file           file delete              To spare subdirectories and their contents  part of your question   modify as follows   void purgeDirectoryButKeepSubDirectories File dir        for  File file  dir listFiles              if   file isDirectory                file delete              Or  since you wanted a one-line solution   for  File file  dir listFiles        if   file isDirectory            file delete      Using an external library for such a trivial task is not a good idea unless you need this library for something else anyway  in which case it is preferrable to use existing code  You appear to be using the Apache library anyway so use its FileUtils cleanDirectory   method

User · Answer

I think this will work  based on NonlinearFruit previous answer     Files walk Paths get  C  test ABC                      sorted Comparator reverseOrder                     map Path  toFile                   filter item - gt   item getPath   equals  C  test ABC                      forEach File  delete     Cheers

User · Answer

public class DeleteFile       public static void main String   args            String path  D  test            File file   new File path           File   files   file listFiles             for  File f files            if  f isFile    amp  amp  f exists                 f delete    system out println  successfully deleted                 else  system out println  cant delete a file due to open or error

User · Answer

Java 8 Stream  This deletes only files from ABC  sub-directories are untouched    Arrays stream new File  C  test ABC    listFiles    forEach File  delete       This deletes only files from ABC  and sub-directories    Files walk Paths get  C  test ABC                      filter Files  isRegularFile                   map Path  toFile                   forEach File  delete       This version requires handling the IOException

[java] Delete all files in directory (but not directory) - one liner solution

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