Getting only file names from the folder in Java8 with Filtering

Question

I want to list out only file names from the folder in Java 8 ending with .txt extension.

With this piece of code I got all the files names, and there are a lot with .txt extensions:

List<Path> fileNames = Files.list(configFilePath)
                .map(Path::getFileName)
                .sorted()
                .collect(toList());

But with this code I get an empty:

List<Path> fileNames = Files.list(configFilePath)
                filter(file -> file.getFileName().endsWith(".txt"))
                .map(Path::getFileName)
                .sorted()
                .collect(toList());

Answer 1

To achieve this, please use the following line of code:

Files.list(configFilePath)
    .filter(s -> s.toString().endsWith(".txt"))
    .forEach(System.out::println);

Your task was to get only file names from the folder which are ending with .txt. So the simplest way to achieve this is to use filter method which takes as an argument a predicate. Using a predicate it means that is keeps all the elements that satisfy the given condition. Because you have a List of Path objects we first need to convert those objects to String and check if it ends with .txt. Finally we just print the result.