This is a tiny dependency-free implementation of glob patterns.

License: MIT

Latest artifacts was deployed to Maven Central:

<dependency>
    <groupId>com.github.acc15</groupId>
    <artifactId>glob</artifactId>
    <version>1.0.0</version>
</dependency>

• ? - matches any single charater
• * - matches any zero-or-more characters
• {variant1,variant2,...,variantN} - matches any of specified variant (variant can contain other expression, including nested variants)
• ** - matches any zero-or-more path segments
• / - path separator (both on windows and unix).

Note that \ character wont work on Windows as path separator and will be treated as simple character, because:

• This will force to write similar globs
• At least on Linux (ext4) file and directory names can contain \ character

Recursively find all PNG files in C:\Users\CurrentUser\photos\cats

Glob glob = Glob.compile("photos/cats/**/*.png");
Set<Path> foundPhotos = glob.scan(Paths.get("C:","Users","CurrentUser"), TargetType.FILE);

Check whether specified path matches glob or not

Glob glob = Glob.compile("photos/cats/**/*.png");
boolean isPhotoOfCat = glob.test(Paths.get("photos", "cats", "trojan.exe"), TargetType.FILE);

Glob class implements Predicate<Path> and therefore can be used in Java 8 Stream API:

Glob glob = Glob.compile("*-cat.{jpg,png}");

List<Path> paths = Arrays.asList(
    Paths.get("the-dog.jpg"),
    Paths.get("the-cat.jpg"),
    Paths.get("the-rat.png"));

boolean isThereAnyCat = paths.stream().anyMatch(glob);
boolean isAllAreCats = paths.stream().allMatch(glob);

List<Path> foundCats = paths.stream().filter(glob).collect(Collectors.toList());

Out-of-box Java globs ( FileSystem#getPathMatcher(String), Files#newDirectoryStream(Path, String)) doesn't support normal zero-or-more directory match syntax (ant-like **). In Java glob patterns ** means 'any character crossing directory boundaries'.

But what if u want to find files starting with letter 'a' and having extension '.png'?

For example consider following file structure:

/photos
    /cats
        /flying
            abc.png
            bac.png
            xyz.png
        abc.png
        bac.png
        xyz.png

And following glob: photos/cats/**/a*.png

It will match PNGs only in child directories of photos/cats (photos/cats/flying, but not in photos/cats) - only 1 file:

• photos/cats/flying/abc.png

More "correct" approach can be: photos/cats/**a*.png

This is better. Will find all needed files. Plus all files having 'a' letter in middle of filename.

Directory stream would return 4 files (instead of expected 2):

• photos/cats/abc.png
• photos/cats/bac.png
• photos/cats/flying/abc.png
• photos/cats/flying/bac.png

Because pattern matches.

This is just not possible with this implementation.