如何从扫描仪读取字符串，并将每个字母转换为不同的值？

Question

I am working on taking a string that has been imported as a file, taking each character, and "encrypting" it by changing it to the next letter. Basically, a is b, b is c, c is d, and etc. It isn't secure but it isn't meant to be for these purposes. The scanned string can be anything but I'm using "Orange juice is great! I drank 83,214 cups of it yesterday." It is in a file called input.txt.

My code is as follows:

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

public class ReadFileExample{

   public static void main(String[] args){

      //String fileName = "input.txt";
      //File file = new File(fileName);
      //Scanner in = new Scanner(file);
      try{
         Scanner in = new Scanner(new File("input.txt"));
         while(in.hasNext() == true){
            String input = in.next();
            System.out.println(input);

            }
         }
         in.close();
      }
      catch(FileNotFoundException exception){
         System.out.println("Could not find the file.");
      }

   }

}

I thought about converting the string to an array but I'm not sure how to go about that. Maybe like this?

char[] charArray = input.toCharArray();
            for (char c : charArray){
               System.out.println(c);
            }

I'm really not sure where to go with this. I also wondered about for(i = 0; i < string.length; i++) Not sure how to go about that either. Once it is done, I need to print it out. Then, I need to take that same string, encrypt it again.

The second file encryption technique is to replace each letter with the place it is in the alphabet. We will use two digits for every letter. For example, the letter 'a' is 01, the letter 'b' is 02, the letter 'c' is 03, the letter 'z' is 26. So that we can use capital letters we start 'A' with 27, 'B' with 28, 'C' with 29, and so on.

For numbers, we convert each digit into two letters: the first two letters that they stand for. The first letter is capitalized followed by a lower-case letter. For example, 8 written out is eight. So, 8 would be encrypted to “Ei”, 1 would be encrypted to “On”, 2 would be encrypted to “Tw”, 3 would be “Th” and so on.

Note that “10” is actually two digits, so it would be encrypted as “1” and “0”: “OnZe”

If you come to a non-letter character (spaces, punctuation, numbers, etc.), just print them as is without encrypting.

Any help is appreciated even if it is suggesting what to search for to answer my questions.

Answer 1

Here is the below code, the code is explained in the comments, if you need more help then comment below, the demo can be found at the below link! I have given the demo for the static string that you have given the example for.

Demo

import java.util.HashMap;

/**
 *
 * @author Sai-Karan
 */
public class App {

    //Function to return the substring for the second encoding method
    //Example 1 will return On, and 2 will return Tw ....etc
    public static String findstringmap(char c)
    {
        //Create a hashmap and add the key elements and the string definitions
      HashMap <Integer, String> hmap = new HashMap <Integer, String>();

       /*Adding elements to HashMap*/
      hmap.put(1, "One");
      hmap.put(2, "Two");
      hmap.put(3, "Three");
      hmap.put(4, "Four");
      hmap.put(5, "Five");
      hmap.put(6, "Six");
      hmap.put(7, "Seven");
      hmap.put(8, "Eight");
      hmap.put(9, "Nine");
      hmap.put(0, "Zero");

      /* Get values based on key*/
      int num_value = Character.getNumericValue(c);
      //convert to the numeric value
      String var = hmap.get(num_value);
      //get the substring
      String ret_str = var.substring(0, 2);
      return ret_str;
    }
    public static void main(String[] args) {
        // TODO code application logic here

        String l1 = "Orange juice is great! I drank 83,214 cups of it yesterday.";
        //String final contains the result
         String Final = "";
         String next = "";
        for(int i =0 ; i< l1.length(); i++)
        {
           //char c = l1.charAt(i);

            if (l1.charAt(i) == ' ')
            {
             next = " ";
            }
            else if (l1.charAt(i) == '!')
            {
             next = "!";
            }
            else if(l1.charAt(i) == ',')
            {
                next = ",";
            }
            else if(l1.charAt(i) == '.')
            {
                next = ".";
            }
            else if(!(Character.isDigit(l1.charAt(i))))
           {
           int val = l1.charAt(i);
           next = String.valueOf( (char) (val + 1));

           // System.out.println(next);
           }
           else if(Character.isDigit(l1.charAt(i)))
           {
               next = findstringmap(l1.charAt(i));

           }
           Final = Final + next;

        }
        System.out.println(Final);
    }

}