Транзакционность javarush

transaction.java

package com.javarush.task.task17.task1721;

import java.io.*;
import java.util.ArrayList;
import java.util.List;

/* 
Транзакционность javarush

*/

public class Solution {
    public static List<String> allLines = new ArrayList<String>();
    public static List<String> forRemoveLines = new ArrayList<String>();

     public static List<String> readFile(String fileName) {
        ArrayList<String> list = new ArrayList<>();
            try {
                BufferedReader reader = new BufferedReader(
                        new InputStreamReader(
                                new FileInputStream(fileName)));

                String line;
                while ((line = reader.readLine()) != null) {
                    list.add(line);
                }
                reader.close();
            } catch (IOException e) {
            }
        return list;
    }

    public static void main(String[] args) throws CorruptedDataException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String fName1 = new String(),
                fName2 = new String();
        try {
            fName1 = reader.readLine();
            fName2 = reader.readLine();
            reader.close();
        }
        catch (IOException e){

            }
            allLines = readFile(fName1);
            forRemoveLines = readFile(fName2);
         new Solution().joinData();
    }

    public void joinData () throws CorruptedDataException {

         /*Важно отделить чтение файлов в мейн и в joinData вынести только работу со списком*/

            if (allLines.containsAll(forRemoveLines)) allLines.removeAll(forRemoveLines);
            else {
                allLines.clear();
                throw new CorruptedDataException();}
            }
}