Simple Java code to list files using NIO while waiting user input to proceed. This can be useful to see how it makes OS/native API calls with strace command.

ListFile.java

import java.io.File;
import java.io.IOException;

import java.nio.file.Path;
import java.nio.file.Files;

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import java.util.Scanner;


public class ListFile {
  private static void waitUserInput(Scanner sc) {
    System.out.println("Press enter key to proceed.");
    sc.nextLine();
  }

  public static void main(String[] args) throws IOException {
    Scanner sc = new Scanner(System.in);

    waitUserInput(sc);
    System.out.println("Start Listing");

    Path path = new File("/tmp").toPath();
    Stream<Path> inputStream = Files.find(path, 1, (p, attr) -> {
      System.out.printf("p=%s, attr=%s\n", p, attr);
      waitUserInput(sc);
      return true;
    });
    List<Path> paths = inputStream.collect(Collectors.toList());

    System.out.printf("paths=%s\n", paths);
  }
}