How to use Files.walk()… to get a graph of files based on conditions?

Question

I have the following directory structures:

/path/to/stuff/org/foo/bar/
/path/to/stuff/org/foo/bar/1.2.3/
/path/to/stuff/org/foo/bar/1.2.3/myfile.ext
/path/to/stu         


        

Answer 1

Adding to @a-better-oliver's answer, here is what you can do if your action declares IOExceptions.

You can treat the filtered stream as an Iterable, and then do your action in a regular for-each loop. This way, you don't have to handle exceptions inside a lambda.

try (Stream pathStream = Files
        .walk(Paths.get("/path/to/stuff/"))
        .filter(p -> p.toString().endsWith(".ext"))
        .map(p -> p.getParent().getParent())
        .distinct()) {

    for (Path file : (Iterable) pathStream::iterator) {
        // something that throws IOException
        Files.copy(file, System.out);
    }
}

Found that trick here: https://stackoverflow.com/a/32668807/1207791