How can I safely encode a string in Java to use as a filename?

Question

I\'m receiving a string from an external process. I want to use that String to make a filename, and then write to that file. Here\'s my code snippet to do this:

Answer 1

This is probably not the most effective way, but shows how to do it using Java 8 pipelines:

private static String sanitizeFileName(String name) {
    return name
            .chars()
            .mapToObj(i -> (char) i)
            .map(c -> Character.isWhitespace(c) ? '_' : c)
            .filter(c -> Character.isLetterOrDigit(c) || c == '-' || c == '_')
            .map(String::valueOf)
            .collect(Collectors.joining());
}

The solution could be improved by creating custom collector which uses StringBuilder, so you do not have to cast each light-weight character to a heavy-weight string.