使用扫描仪读取文本文件并存储到ArrayList

Question

I have an assignment to create a program that calculates an actor's Bacon Number. Here is the contents of my given ActorMovieTist.txt file which is supposed to be read in my program.

Adolf Hitler Der Ewige Jude 1940 
Angelina Jolie Mr. & Mrs. Smith 2005
Anne Hathaway Valentine's Day 2010
Benedict Cumberbatch The Hobbit: An unexpected Journey 2012
Benedict Cumberbatch Black Mass 2015
Brad Pitt Mr. & Mrs. Smith 2005
Brad Pitt Sleepers 1996
Brad Pitt Ocean's Thirteen 2007
Brad Pitt Beyond All Boundaries 2009
Brad Pitt Se7en 1995
Christian Bale The Fighter 2010
Curt Bois Der Ewige Jude 1940
Curt Bois The Great Sinner 1949
Denzel Washington 2 Guns 2013
Denzel Washington The Equalizer 2014
David Struffolino The Equalizer 2014
David Struffolino Knight and Day 2010
Hugh Jackman Flushed Away 2006
Hugh Jackman X Men First Class 2011
Ian McKellen The Hobbit: An unexpected Journey 2012
Julia Roberts Valentine's Day 2010
Julia Roberts Flatliners 1990
Kate Winslet Flushed Away 2006
Kenneth Tobey The Great Sinner 1949
Kenneth Tobey Hero at Large 1980
Kevin Bacon Sleepers 1996
Kevin Bacon Beyond All Boundaries 2009
Kevin Bacon Flatliners 1990
Kevin Bacon Patriots Day 2016
Kevin Bacon Black Mass 2015
Kevin Bacon X Men First Class 2011
Kevin Bacon Hero at Large 1980
Kevin Spacey Se7en 1995
Kevin Spacey Patriots Day 2016
Kevin Spacey Austin Powers in Goldmember 2002
Mark Wahlberg 2 Guns 2013
Mark Wahlberg Patriots Day 2016
Mark Wahlberg The Fighter 2010
Matt Damon Ocean's Thirteen 2007
Tom Cruise Austin Powers in Goldmember 2002

Here is my program which is supposed to use Scanner to read this file and save each Line as an element of an ArrayList but it doesn't. I printed the size of the ArrayList at the end but my program keeps saying 0. What am I doing wrong?

import java.util.*;
import java.io.File;
import java.io.IOException;



public class KevinBacon
{
    public static void main(String args[]) throws Exception{ 
        Formatter output = new Formatter("ActorMovieList.txt");
        File file = new File("ActorMovieList.txt");
        Scanner input = new Scanner(file);
        String line = "";

    ArrayList <String> list = new ArrayList <String>(); 

    while (input.hasNextLine()) {
        list.add(input.nextLine());
    }

    System.out.println(list.size());
}

}

Answer 1

You are overwriting your input file when you do

Formatter output = new Formatter("ActorMovieList.txt");

If the file exists then it will be truncated to zero size; otherwise, a new file will be created

as you do not seems to be using this output object, simply delete this line and recreate your input file.