OnJava8-Examples/streams/TreeSetOfWords.java

// streams/TreeSetOfWords.java
// (c)2016 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.*;
import java.util.stream.*;

public class TreeSetOfWords {
  public static void
  main(String[] args) throws Exception {
    Set<String> words2 =
      Files.lines(Paths.get("TreeSetOfWords.java"))
        .flatMap(s -> Arrays.stream(s.split("\\W+")))
        .filter(s -> !s.matches("\\d+")) // No numbers
        .map(String::trim)
        .filter(s -> s.length() > 2)
        .limit(100)
        .collect(Collectors.toCollection(TreeSet::new));
    System.out.println(words2);
  }
}
/* Output:
[Arrays, Collectors, Exception, Files, Output, Paths, Set,
String, System, TreeSet, TreeSetOfWords, args, class,
collect, file, filter, flatMap, get, import, java, length,
limit, lines, main, map, matches, new, nio, numbers, out,
println, public, split, static, stream, streams, throws,
toCollection, trim, util, void, words2]
*/