比较两个导入的文本文件

Question

Hey guys just wanted to see if what I'm thinking will work, I am in my second semester of learning java. Here's the directions for a hw assignment: Design a class that checks if the contents of two text files are identical and, if not, determines how many lines are different. Lines are different if they differ in one or more characters. So, I'm thinking that I should read in the texts line by line, convert each line to a string and then store each line in a spot in an array.Once I have done this I will have to arrays. Then, I plan on going through each array and comparing them. Is my thinking on this problem correct?

import java.io.*;
import java.util.*;

public class myfilereader
{
    public static void main (String[] args) throws java.io.IOException
    {
        ArrayList<String> Diff = new ArrayList<String>();
        Scanner s = new Scanner(new File("/Users/Home/Desktop/File2.txt"));
        ArrayList<String> ArrayList1 = new ArrayList<String>();
        while (s.hasNext())
        {
            ArrayList1.add(s.next());
        }
        s.close();

        Scanner s1 = new Scanner(new File("/Users/Home/Desktop/File1.txt"));
        ArrayList<String> ArrayList2 = new ArrayList<String>();
        while (s.hasNext())
        {
            ArrayList2.add(s1.next());
        }
        s1.close();
        HashSet hs = new HashSet();
        for(String i : ArrayList1) hs.add(i);
        for(String i : ArrayList2)
        {
            if(!hs.add(i))
                Diff.add(i);
        }

        String result = "+";
        for (int i = 0; i < Diff.size(); i++)
        {   
            result += " " + Diff.get(i);
        }
        System.out.println(result);

    }
}

Here are the exact errors I'm getting"

Exception in thread "main" java.lang.IllegalStateException: Scanner closed
    at java.util.Scanner.ensureOpen(Scanner.java:1046)
    at java.util.Scanner.hasNext(Scanner.java:1310)
    at myfilereader.main(myfilereader.java:19)

Answer 1

我将使用它： Apache Commons Collections然后将两个文件加载到ArrayList中，并使用Collections方法之一