// Example 124 from page 97 of Java Precisely second edition (The MIT Press 2005)
// Author: Peter Sestoft (sestoft@itu.dk)

import java.util.*;
import java.io.*;

class Example124 {
  public static void main(String[] args) {
    SortedSet<String> filenames = new TreeSet<String>();
    File cwd = new File(".");           // Current working directory
    for (File f : cwd.listFiles()) 
      filenames.add(f.getName());
    for (String filename : filenames.subSet("P", "T")) 
      System.out.println(filename);
  }
}