需要一种方法来读取两个文件并使用扫描仪类输出差异

Question

这是我目前所拥有的。我不知道从这里去哪里。我需要一种方法来输出两个文件的差异

    package JwolfrumCh6;
    import java.util.*;
    import java.io.*;
    import java.util.Scanner;

    public class JwolfrumCh6 {

        public static void main(String[] args) throws FileNotFoundException  
    {
            Scanner console = new Scanner(System.in);

            System.out.print("Enter File one Name");
            String file1 = console.nextLine();
            Scanner input1 = new Scanner(new File(file1));

            System.out.print("Enter File two Name");
            String file2 = console.nextLine();
            Scanner input2 = new Scanner(new File(file2));
        }
        public static void compareFiles(Scanner input1, Scanner input2) {

            while(input1.hasNextLine() || input2.hasNextLine()) {

            }

        }
    }

Answer 1

在 main 中调用静态方法并在 compareFiles 方法中实现以下逻辑。

1. 将文件 1 的所有行读取到一个 ArrayList
2. 将文件 2 的所有行读取到另一个 ArrayList

3. 使用如下所示的ArrayList的removeAll方法来获取每个文件的差异。

   import java.io.File;
   import java.io.FileNotFoundException;
   import java.util.ArrayList;
   import java.util.List;
   import java.util.Scanner;
   
   public class FML {
   
   public static void main(String[] args) throws FileNotFoundException {
       Scanner console = new Scanner(System.in);
   
       System.out.print("Enter File one Name");
       String file1 = console.nextLine();
       Scanner input1 = new Scanner(new File(file1));
   
       System.out.print("Enter File two Name");
       String file2 = console.nextLine();
       Scanner input2 = new Scanner(new File(file2));
       compareFiles(input1, input2);
   }
   
   public static void compareFiles(Scanner input1, Scanner input2) {
        List<String> list1 = new ArrayList<String>();
        List<String> list2 = new ArrayList<String>();
       while (input1.hasNextLine()) {
           list1.add(input1.nextLine());
       }
       while (input2.hasNext()) {
           list2.add(input2.nextLine());
       }
       List<String> tmpList = new ArrayList<String>(list1);
       tmpList.removeAll(list2);
   
       System.out.println("content from file1 which is different from file2");
       for(int i=0;i<tmpList.size();i++){
           System.out.println(tmpList.get(i)); 
       }
   
       System.out.println("content from file2 which is different from file2");
   
       tmpList = list2;
       tmpList.removeAll(list1);
       for(int i=0;i<tmpList.size();i++){
           System.out.println(tmpList.get(i)); 
       }
   
   }
   }