Java - Search for files in a directory

Question

This is supposed to be simple, but I can't get it - "Write a program that searches for a particular file name in a given directory." I've found a few examples of a hardcoded filename and directory, but I need both the dir and file name to be as entered by the user.

public static void main(String[] args) {
    String fileName = args[0]; // For the filename declaration
    String directory;     
    boolean found;

    File dir = new File(directory);

    File[] matchingFiles = dir.listFiles(new FilenameFilter() {
        public boolean accept(File dir, String fileName) {
            return true;
        }
    });

}

Answer 1

With **Java 8* there is an alternative that use streams and lambdas:

public static void recursiveFind(Path path, Consumer<Path> c) {
  try (DirectoryStream<Path> newDirectoryStream = Files.newDirectoryStream(path)) {
    StreamSupport.stream(newDirectoryStream.spliterator(), false)
                 .peek(p -> {
                   c.accept(p);
                   if (p.toFile()
                        .isDirectory()) {
                     recursiveFind(p, c);
                   }
                 })
                 .collect(Collectors.toList());
  } catch (IOException e) {
    e.printStackTrace();
  }
}

So this will print all the files recursively:

recursiveFind(Paths.get("."), System.out::println);

And this will search for a file:

recursiveFind(Paths.get("."), p -> { 
  if (p.toFile().getName().toString().equals("src")) {
    System.out.println(p);
  }
});