ExtensionFilter.java

import java.io.File;
import java.io.FilenameFilter;

public class ExtensionFilter implements FilenameFilter {
	String extension;

	public ExtensionFilter (String extension) {
		this.extension = extension;
	}

	public boolean accept (File file, String fileName) {
		fileName = fileName.toLowerCase ();

		return (fileName.endsWith (extension));
	}
}

Main.java

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Scanner;

public class Main {
	public static ExtensionFilter extensionFilter;
	public static int directoriesNum = 0, filesNum = 0;
	public static long sizeTotal = 0;

	public static void main (String[] args) {
		File directory;
		File[] files;
		Scanner scanner = new Scanner (System.in);
		String dirName, filter;

		scanner.useDelimiter ("\n");
		System.out.print ("Nazev adresare: ");
		dirName = scanner.next ();

		System.out.print ("Filtr: ");
		filter = scanner.next ();

		extensionFilter = new ExtensionFilter (filter);

		directory = new File (System.getProperty ("user.home") + File.separator + dirName);

		if (directory.exists ()) {
			System.out.format ("%-30s%15s %-21s%3s\n", "Nazev souboru", "Velikost", "Vytvoreno", "Prava");
			printSeparator ();

			files = directory.listFiles ();

			listDirectories (files);
			listFiles (files);

			printSeparator ();
			System.out.println ("Adresaru: " + directoriesNum + ", souboru: " + filesNum + " o celkove velikosti "
					+ sizeTotal + " bajtu.");
		} else {
			System.out.println ("Soubor neexistuje.");
		}
	}

	private static void listFiles (File[] files) {
		String modified, length, accessRights;

		for (File file : files) {
			if (file.isFile () && extensionFilter.accept (file, file.getName ())) {
				length = file.length () + "b";
				modified = getModified (file);
				accessRights = getAccessRights (file);

				System.out.format ("%-30s%15s %-21s%-3s\n", file.getName (), length, modified, accessRights);
				sizeTotal += file.length ();
				filesNum++;
			}
		}
	}

	private static void listDirectories (File[] files) {
		String modified, accessRights;

		for (File file : files) {
			if (file.isDirectory () && extensionFilter.accept (file, file.getName ())) {
				modified = getModified (file);
				accessRights = getAccessRights (file);

				System.out.format ("%-30s%-15s %-21s%-3s\n", file.getName (), "---------------",
						modified, accessRights);
				directoriesNum++;
			}
		}
	}

	private static String getModified (File file) {
		SimpleDateFormat dateFormat = new SimpleDateFormat ("dd. MM. yy, HH.mm:ss");
		String modifiedString;
		long modified;

		modified = file.lastModified ();
		modifiedString = dateFormat.format (modified);

		return (modifiedString);
	}

	private static String getAccessRights (File file) {
		StringBuffer accessRights = new StringBuffer ();

		accessRights.append ((file.canRead ()) ? "r" : "-");
		accessRights.append ((file.canWrite ()) ? "w" : "-");
		accessRights.append ((file.canExecute ()) ? "x" : "-");

		return (accessRights.toString ());
	}

	private static void printSeparator () {
		System.out.println ("========================================================================");
	}
}