OnJava8-Examples/collections/UniqueWords.java

// collections/UniqueWords.java
// (c)2020 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.*;
import java.nio.file.*;

public class UniqueWords {
  public static void
  main(String[] args) throws Exception {
    List<String> lines = Files.readAllLines(
      Paths.get("SetOperations.java"));
    Set<String> words = new TreeSet<>();
    for(String line : lines)
      for(String word : line.split("\\W+"))
        if(word.trim().length() > 0)
          words.add(word);
    System.out.println(words);
  }
}
/* Output:
[A, B, C, Collections, D, E, F, G, H, HashSet, I, J, K,
L, M, N, Output, Set, SetOperations, String, System, X,
Y, Z, add, addAll, added, args, class, collections,
contains, containsAll, false, from, import, in, java,
main, new, out, println, public, remove, removeAll,
removed, set1, set2, split, static, to, true, util,
void]
*/