Question

所以我需要帮助增加文件中的所有字符。整个文件能够从用户那里读取并获取所有信息，但是当涉及实际增加（本例）文件中的所有字符时，它只输出一个空白文件。

此程序的目标是读入用户文件，从文件中获取所有文本，并将字母增加或减少一个。所以A现在是B或B现在是C或者反之亦然B现在是A或C现在是B.当它导出/关闭文件时它只是空白。

以下是代码的一部分： while（fileIn.hasNext（）） { letter.add（fileIn.next（））;

           for (int i = letter.size() - 1; i >= 0; i--)
           {
              ch = letter.get(i).charAt(0);

              ch--;

              fileout1.println(ch);
           }

           //Makes a new line at end of line
           System.out.println();
        }

整个代码如下：

import java.util.*;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.PrintWriter;
import java.io.File;
import java.util.ArrayList;

public class Assignment9
{

   public static void main (String[] args)
   {
      Scanner in = new Scanner (System.in);
      Scanner fileIn;
      File f; 
      char ch = 65;
      String fileName = "";
      boolean userA = false;
      String usersChoice = "";
      ArrayList<String> letter = new ArrayList<String>();


      try
      {
         System.out.println("Please enter the file name that you would like encrypted/decrypted: ");
         fileName = in.nextLine();

         //Builds the file and attaches the Scanner
         f = new File (fileName);
         fileIn = new Scanner (f);
         PrintWriter fileout1 = new PrintWriter ("decrypt.txt");
         PrintWriter fileout2 = new PrintWriter ("encrypt.txt");


         System.out.println("Would you like to Decrypt or Encrypt the file?");  
         usersChoice = in.nextLine();
         userA = true;


         //Loop through the file and translate the characters
         if (usersChoice.equalsIgnoreCase("Decrypt"))
         {
            while (fileIn.hasNext())
            {
               letter.add(fileIn.next());

               for (int i = letter.size() - 1; i >= 0; i--)
               {
                  ch = letter.get(i).charAt(0);

                  ch--;

                  fileout1.println(ch);
               }

               //Makes a new line at end of line
               System.out.println();
            }

            //Decrease every letter by 1 (runs backwords)


            System.out.println("Decrypt.txt has been created.");
            fileout1.close();

         }

         //encrypts the file by increasing by 1
         if (usersChoice.equalsIgnoreCase("encrypt"))
         {
            while (fileIn.hasNext())
            {
               letter.add(fileIn.next());
            }

            //Decrease every letter by 1 (runs backwords)
            for (int i = letter.size() -1; i >= 0; i--)
            {
                System.out.println(letter);

               ch --;
            }

            System.out.println("Encrypted.txt has been created.");
            fileout2.close();;
         }             
      } //end of try     

      catch (FileNotFoundException e)
      {
         System.out.println("Sorry invalid file, please try again");
         fileName = in.nextLine();
      }


   } // end of main

} //end of program

Answer 1

您可以执行以下操作，

    FileReader fr = null;
    FileWriter fw = null;
    int c;
    try {
        fr = new FileReader("C:\\Zia\\test.txt");
        fw = new FileWriter("C:\\Zia\\Result.txt");
        while ((c = fr.read()) != -1) {
            if(c!=32)
            fw.write((char)--c);
            else
                fw.write((char)c);
        }
    } catch(IOException e) {
        e.printStackTrace();
    } finally {
        close(fr);
        close(fw);
    }

我的test.txt文件包含以下内容，

Hello How are you doing.

和result.txt在将char减少一之后包含以下结果。

Gdkkn Gnv `qd xnt cnhmf-

您可以为Reader和writer的文件交换文件名，并将char增加1以验证解密。

将所有字符增加1（JAVA）

1 个答案: