CustomFileChooser.java

import java.io.*;
import java.nio.file.*;
import java.nio.file.spi.FileSystemProvider;
import java.util.*;
import java.util.function.Function;
import java.util.stream.Collectors;
import javax.swing.*;

public class CustomFileChooser {

	public static void main(String[] args) throws IOException {
		Function<String, Integer> countDir = str -> (str.length() - str.replace("/", "").length());

		List<String> directories = runCommand("cd ~/Documents && find . -type d ")
				.stream()
				.map(str -> str.substring(1))
				.sorted((o1, o2) -> {
					Integer o1Count = countDir.apply(o1);
					Integer o2count = countDir.apply(o2);
					if (o1Count > o2count) return 1;
					else if (o2count > o1Count) return -1;
					else return 0;
				})
				.collect(Collectors.toList());
		directories.forEach(System.out::println);

		String url = System.getProperty("java.io.tmpdir") + "/javaFileChooser";
		System.out.println(url);
		File file = new File(url);
		Path p = Files.createDirectory(file.toPath());

		Runtime.getRuntime().addShutdownHook(new Thread(() -> runCommand("rm -rf " + file.toPath())));

		FileSystemProvider.installedProviders().get(0).checkAccess(file.toPath(), AccessMode.WRITE);

		directories.forEach(str -> {
			try {
				Files.createDirectory(new File(file.toPath().toString() + "/" + str).toPath());
			} catch (Exception e) {
				e.printStackTrace();
			}
		});
		final JFileChooser fc = new JFileChooser();
		fc.setCurrentDirectory(file);
		fc.setSize(400, 400);
		fc.setVisible(true);
		fc.setControlButtonsAreShown(true);
		int returnVal = fc.showOpenDialog(null);

	}

	public static List<String> runCommand(String command) {
		try (InputStream inputStream = Runtime.getRuntime()
				.exec(new String[]{"sh", "-c", command}).getInputStream();
		     Reader in = new InputStreamReader(inputStream)) {

			return new BufferedReader(in).lines().collect(Collectors.toList());

		} catch (IOException e) {
			return Collections.emptyList();
		}
	}
}