Array of Path using nio

I'm just studying topic nio and got the following task:
do recursive search of file name using nio. The method should return a list of found Path.
When I run the code below in output I see only [ ]. Could someone explain and correct me?

public class Task01 {
    public static void main(String[] args) throws IOException {
        Path dir = Paths.get("C:\\Users\\......");
        System.out.println(findFile(dir, "Task01.java"));
    }

    public static ArrayList<Path> findFile(Path path, String filename) throws IOException {
        Path dir = Paths.get("C:\\....");
        ArrayList<Path> list1 = new ArrayList<>();

        try (DirectoryStream<Path> stream = Files.newDirectoryStream(path, filename)) {
            for (Path entry : stream) {
                if (path.toFile().isDirectory()) {
                    findFile(path, filename);
                } else list1.add(entry.toAbsolutePath());
            }

        }
        return list1;
    }
}

First of all, when doing the recursion, you want to use entry instead of path, otherwise you are not going down the directory tree.

Also use Files.newDirectoryStream(path) instead of Files.newDirectoryStream(path, fileNamePattern) the second method creates a stream in the path whose filename matches fileNamePattern, in your case it will be empty [] if your Test.java is not located in path

public static void main(String[] args) throws IOException {
    Path dir = Paths.get("E:\\dev\\...");
    System.out.println(findFile(dir, "TestA.java"));
}

public static ArrayList<Path> findFile(Path path, String filename) throws IOException {
    ArrayList<Path> list1 = new ArrayList<>();

    try (DirectoryStream<Path> stream = Files.newDirectoryStream(path)) {
        for (Path entry : stream) {
            if (Files.isDirectory(entry)) {
               list1.addAll(findFile(entry, filename));
            } else if(entry.getFileName().endsWith(filename)){
               list1.add(entry.toAbsolutePath());
            }
        }
    }
    return list1;
}

This code may work for you:

public static ArrayList<Path> findFile(Path path, String filename) throws IOException {
    ArrayList<Path> list1 = new ArrayList<>();

    try (DirectoryStream<Path> stream = Files.newDirectoryStream(path,filename)) {
        for (Path entry : stream) {
        	System.out.println(entry+ "-"+entry.getFileName());
            if (Files.isDirectory(entry)) {
            	list1.addAll(findFile(entry, filename));
            } 
            else if (entry.getFileName().toString().equals(filename)) 
            	list1.add(entry.toAbsolutePath());
        }

    }
    return list1;
}

• When passing filename to Files.newDirectoryStream(path,filename) it will only search in the path itself, no subdirectories. So you may not pass the filename here to filter.
• if you call your method recursively you must also make sure the return values are passed upwards: list1.addAll(findFile(entry, filename));
• within the for loop always work with entry, not path otherwise you are not processing your directory structure recursively. (see Files.isDirectory(entry) instead of path.toFile().isDirectory()

UPDATE: improved usage of java.nio API (thanks to @Andreas). It's correct I'm less familiar with the nio api.