Read all lines from FileChannel to Stream of strings

Question

For my specific task, I need to read the data from FileChannel to a Stream (or Collection) of String\'s.

In a regular

Answer 1

I assume you want the channel to be closed when the returned Stream is closed, so the simplest approach would be

public static Stream<String> lines(FileChannel channel) {
    BufferedReader br = new BufferedReader(Channels.newReader(channel, "UTF-8"));
    return br.lines().onClose(() -> {
        try { br.close(); }
        catch (IOException ex) { throw new UncheckedIOException(ex); }
    });
}

It doesn’t actually require a FileChannel as input, a ReadableByteChannel is sufficient.

Note that this also belongs to “regular NIO”; java.nio.file is sometimes referred to as “NIO.2”.