List all files and folders from the Directory

ListAllFiles.java

import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

class ToAbsoluteFilePath {
  public static List<File> listFiles(String directoryName) {
      File directory = new File(directoryName);

      List<File> resultList = new ArrayList<>();

      // get all the files from a directory
      File[] fList = directory.listFiles();
      resultList.addAll(Arrays.asList(fList));
      for (File file : fList) {
          if (file.isFile()) {
              resultList.add(file);
          } else if (file.isDirectory()) {
              resultList.addAll(listFiles(file.getAbsolutePath()));
          }
      }
      return resultList;
  }
}