FileLineByLine.java

import java.io.IOException;
import java.util.List;
import java.util.function.Function;
import java.util.stream.Stream;

import static java.nio.file.Files.lines;
import static java.nio.file.Paths.get;
import static java.util.stream.Collectors.toList;

public class FileLineByLine {


    private static <T> List<T> file2T(String fileName, Function<String, T> transform) throws IOException {
        try (Stream<String> stream = lines(get(fileName))) {

            return stream
                    .map(line -> transform.apply(line))
                    .collect(toList());
        }
    }

    

    public static void main(String args[]) throws Exception {

        List<Double> doubles = file2T(args[0], Double::parseDouble);

        System.out.println(doubles);
    }
}