java - How to find sub-directories in a directory/folder?

Question

I'm looking for a way to get all the names of directories in a given directory, but not files.

For example, let's say I have a folder called Parent, and inside that I have 3 folders: Child1 Child2 and Child3.

I want to get the names of the folders, but don't care about the contents, or the names of subfolders inside Child1, Child2, etc.

Is there a simple way to do this?

Answer 1

If you are on java 7, you might wanna try using the support provided in

package java.nio.file 

If your directory has many entries, it will be able to start listing them without reading them all into memory first. read more in the javadoc: http://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html#newDirectoryStream(java.nio.file.Path,%20java.lang.String)

Here is also that example adapted to your needs:

public static void main(String[] args) {
    DirectoryStream.Filter<Path> filter = new DirectoryStream.Filter<Path>() {
        @Override
        public boolean accept(Path file) throws IOException {
            return (Files.isDirectory(file));
        }
    };

    Path dir = FileSystems.getDefault().getPath("c:/");
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir, filter)) {
        for (Path path : stream) {
            // Iterate over the paths in the directory and print filenames
            System.out.println(path.getFileName());
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}