Reading a file path without knowing the file Directory or parent file

Question

I'm writing a java program that needs to find a file directory only having the file name. For example, I know the file is called “Img_123.png” but I do not know it's file directory, file name, or file path. I need to know the entire file name in as a string(in order to draw it using Canvas).

Answer 1

Provided root folder to start your search and the max allowed depth, this should return list of all files that match the filename:

List<File> findFileByName(Path start, String fileName, int maxDepth) throws IOException {
  final Stream<Path> files = Files.find(start, maxDepth, (path, attribute) -> { 
    return path.endsWith(fileName);
  });
  return files
    .map(path -> path.toFile())
    .collect(Collectors.toList());
}

(path, attribute) -> { //any code } that you're confused about is a lambda expression an anonymous function . It's type is BiPredicate<Path,BasicFileAttributes> which means it should return a Boolean based on some evaluation of the path and attributes for the file being processed.