Java List only subdirectories from a directory not files

Question

In Java  How do I list only subdirectories from a directory   I d like to use the java io File functionality  what is the best method in Java for doing this

User · Accepted Answer

You can use the File class to list the directories.

File file = new File("/path/to/directory");
String[] directories = file.list(new FilenameFilter() {
  @Override
  public boolean accept(File current, String name) {
    return new File(current, name).isDirectory();
  }
});
System.out.println(Arrays.toString(directories));

Update

Comment from the author on this post wanted a faster way, great discussion here: How to retrieve a list of directories QUICKLY in Java?

Basically:

If you control the file structure, I would try to avoid getting into that situation.
In Java NIO.2, you can use the directories function to return an iterator to allow for greater scaling. The directory stream class is an object that you can use to iterate over the entries in a directory.

User · Answer

This will literally list  that is  print  all subdirectories  It basically is a loop kind of where you don   t need to store the items in between to a list  This is what one most likely needs  so I leave it here  Path directory   Paths get  quot D   directory  to  list quot     Files walk directory  1  filter entry - gt   entry equals directory        filter Files  isDirectory  forEach subdirectory - gt           do whatever you want with the subdirectories     System out println subdirectory getFileName

User · Answer

ArrayList lt File gt  directories   new ArrayList lt File gt       Arrays asList          new File  your path    listFiles File  isDirectory

User · Answer

Here is solution for my code  I just did a litlle change from first answer  This will list all folders only in desired directory line by line   try               File file   new File  D   admir  MyBookLibrary                String   directories   file list new FilenameFilter                    Override               public boolean accept File current  String name                    return new File current  name  isDirectory                                                for int i   0 i  lt  directories length i                      if directories i     null                        System out println Arrays asList directories i                                               catch Exception e                System err println  Error

User · Answer

You can use the JAVA 7 Files api Path myDirectoryPath   Paths get  quot path to my directory quot    List lt Path gt  subDirectories   Files find                      myDirectoryPath                       Integer MAX VALUE                       filePath  fileAttr  - gt  fileAttr isDirectory    amp  amp   filePath equals myDirectoryPath                 collect Collectors toList      If you want a specific value you can call map with the value you want before collecting the data

User · Answer

Mohamed Mansour you were almost there    the  dir  argument from that you were using is actually the curent path  so it will always return true  In order to see if the child is a subdirectory or not you need to test that child   File file   new File   path to directory    String   directories   file list new FilenameFilter        Override   public boolean accept File current  String name        return new File current  name  isDirectory            System out println Arrays toString directories

User · Answer

File files   new File  quot src quot           src is folder name          This will return the list of the subDirectories     List lt File gt  subDirectories   Arrays stream files listFiles    filter File  isDirectory  collect Collectors toList        this will print all the sub directories Arrays stream files listFiles    filter File  isDirectory  forEach System out  println

User · Answer

For those also interested in Java 7 and NIO  there is an alternative solution to  voo s answer above  We can use a try-with-resources that calls Files find   and a lambda function that is used to filter the directories   import java io IOException  import java nio file Files  import java nio file Path  import java nio file Paths  import java util stream Stream    final Path directory   Paths get   path to folder     try  Stream lt Path gt  paths   Files find directory  Integer MAX VALUE   path  attributes  - gt  attributes isDirectory           paths forEach System out  println     catch  IOException e                We can even filter directories by name by changing the lambda function    path  attributes  - gt  attributes isDirectory    amp  amp  path toString   contains  test     or by date   final long now   System currentTimeMillis    final long yesterday   new Date now - 24   60   60   1000L  getTime        modified in the last 24 hours  path  attributes  - gt  attributes isDirectory    amp  amp  attributes lastModifiedTime   toMillis    gt  yesterday

User · Answer

The solution that worked for me  is missing from the list of answers  Hence I am posting this solution here   File  dirs   new File   mypath mydir    listFiles  FileFilter FileFilterUtils directoryFileFilter       Here I have used org apache commons io filefilter FileFilterUtils from Apache commons-io-2 2 jar  Its documentation is available here  https   commons apache org proper commons-io javadocs api-2 2 org apache commons io filefilter FileFilterUtils html

User · Answer

In case you re interested in a solution using Java 7 and NIO 2  it could go like this   private static class DirectoriesFilter implements Filter lt Path gt         Override     public boolean accept Path entry  throws IOException           return Files isDirectory entry            try  DirectoryStream lt Path gt  ds   Files newDirectoryStream FileSystems getDefault   getPath root   new DirectoriesFilter               for  Path p   ds                System out println p getFileName                     catch  IOException e            e printStackTrace

User · Answer

Given a starting directory as a String   Create a method that takes a String path as the parameter   In the method  Create a new File object based on the starting directory Get an array of files in the current directory using the listFiles method Loop over the array of files  If it s a file  continue looping If it s a directory  print out the name and recurse on this new directory path

User · Answer

A very simple Java 8 solution   File   directories   new File   your path    listFiles File  isDirectory     It s equivalent to using a FileFilter  works with older Java as well    File   directories   new File   your path    listFiles new FileFilter          Override     public boolean accept File file            return file isDirectory

User · Answer

I d like to use the java io File functionality    In 2012  date of the question  yes  not today   java nio API has to be favored for such requirements    Terrible with so many answers  but not the simple way that I would use that is Files walk   filter   collect       Globally two approaches are possible       1 Files walk Path start    has no maxDepth limitations while   2 Files walk Path start  int maxDepth  FileVisitOption    options  allows to set it   Without specifying any depth limitation  it would give    Path directory   Paths get   foo bar     try       List lt Path gt  directories               Files walk directory                    filter Files  isDirectory                    collect Collectors toList       catch  IOException e           process exception     And if for legacy reasons  you need to get a List of File you can just add a map Path  toFile  operation before the collect     Path directory   Paths get   foo bar     try       List lt File gt  directories               Files walk directory                    filter Files  isDirectory                    map Path  toFile                    collect Collectors toList       catch  IOException e           process exception

[java] Java, List only subdirectories from a directory, not files

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