Quick-and-dirty way to count the lines of Java source code of a project

CountLines.java

// Quick-and-dirty way to count the lines of Java source code of a project
System.out.println(Files.walk(Paths.get("."))
        .map(e -> e.toFile())
        .filter(f -> f.isFile() && f.canRead())
        .filter(f -> f.getName().endsWith(".java"))
        .mapToLong(f -> {
            try { return new BufferedReader(new FileReader( f )).lines().count();
            } catch (Exception ex) { throw new RuntimeException(ex); }
        })
        .reduce(0, (acc, current) -> acc + current));