ProbeFileInParallel.java

import java.io.IOException;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author Ivan Babanin ([email protected])
 */
public class ProbeFileInParallel {
  public static void main(String[] args) throws IOException {
    final List<Path> paths = new ArrayList<>();
    try (DirectoryStream<Path> stream = Files.newDirectoryStream(Paths.get("."), "*.{docx}")) {
      for (Path path : stream) {
        paths.add(path);
      }
    }

    System.out.println("Found following files: ");
    for (Path path : paths) {
      System.out.println("\t" + path);
    }

    System.out.println("Probing...");
    final ExecutorService executorService = Executors.newFixedThreadPool(20);
    for (int i = 0; i < 20; i++) {
      executorService.submit(new Runnable() {
        @Override
        public void run() {
          for (Path path : paths) {
            try {
              System.out.println(Files.probeContentType(path));
            } catch (IOException e) {
              e.printStackTrace();
            }
          }
        }
      });
    }
  }
}