OTP with random alphabet value

This is One Time Pad Cipher with random alphabet value as shown below

A-7    B-10    C-19    D-23    E-0    F-22    G-6    H-25   I-9    J-1 
K-15   L-4     M-21    N-20    O-16   P-8     Q-17   R-5    S-24   T-3
U-11   V-12    W-14    X-2     Y-13   Z-18

Plain text = COMPUTER
KEY = SOVIET

Encryption

 FORMULA (cipher + key) % 26

        C    O    M    P    U   T   E   R
        S    O    V    I    E   T   S   O
        -----------------------------------
  (%26) 17   6    7    17   11  6   24  21
        -----------------------------------
        Q    G    A    Q    U   G   S   M

Decryption

 FORMULA = ((cipher + 26) - key) % 26
 
        Q    G    A    Q    U   G   S   M
        ------------------------------------
        17   6    7    17   11  6   24  21
  (+26) 43   32   33   43   37  32  50  47
        ------------------------------------
        S    O    V    I    E   T   S   O
        24   16   12   9    0   3   24  16
 (-KEY) 19   16   21   34   37  29  26  31
        ------------------------------------
  (%26) 19   16   21   8    11  3   0   5
        ------------------------------------
        C    O    M    P    U   T   E   R

Change Snippet Background Color

default solarized dark solarized light github railscasts monokai-sublime mono-blue tomorrow color-brewer zenburn agate androidstudio dracula rainbow vs

          
            
/*

*/
import java.util.*;

public class OTPCipher2{
                                //  A B  C  D  E  F G H  I J K  L M  N  O  P Q  R S  T U  V  W  X Y  Z
   private static Integer[] list = {7,10,19,23,0,22,6,25,9,1,15,4,21,20,16,8,17,5,24,3,11,12,14,2,13,18};
   private static String alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
   
   public static void main(String[] args){
      String text = "REPEAT ATTACK TONIGHT";
      String key = "SOVIET";
      String k = "";
      int len = text.length();
      if(key.length()<len){
         int count = 0;
         for(int x=0;x<len;x++){  
            if(count == key.length()) 
               count = 0;
               
            k = k+key.charAt(count);
            count++;
         }
         key = k;
      }
      
      String enc = OTPEncryption(text,key);
      System.out.println("Plaintext : "+text);
      System.out.println("Encrypted : "+enc);
      System.out.println("Decrypted : "+OTPDecryption(enc,key));
   }
   
   public static String RandomAlpha(int len){
      Random r = new Random();
      String key = "";
      for(int x=0;x<len;x++)
         key = key + (char) (r.nextInt(26) + 'A');
      return key;
   }
   
   public static String OTPEncryption(String text,String key){
      int len = text.length();
      String sb= "";
      for(int x=0;x<len;x++){
         char get = text.charAt(x);
         char keyget = key.charAt(x);
         if(Character.isUpperCase(get)){
            int index = list[alpha.indexOf(get)];
            int keydex = list[alpha.indexOf(keyget)];
            
            int total = (index + keydex) % 26;
            
            sb = sb + alpha.charAt(Arrays.asList(list).indexOf(total));
         }
         else{
            sb = sb + get;
         }
      }
      
      return sb;
   }
   public static String OTPDecryption(String text,String key){
      int len = text.length();
      
      String sb = "";
      for(int x=0;x<len;x++){
         char get = text.charAt(x);
         char keyget = key.charAt(x);
         if(Character.isUpperCase(get)){
            int index = list[alpha.indexOf(get)];
            int keydex = list[alpha.indexOf(keyget)];

            int total = (index + 26) - keydex;
            total = total % 26;
            
            sb = sb + alpha.charAt(Arrays.asList(list).indexOf(total));
         }
         else{
            sb = sb + get;
         }
      }
      return sb;
   }   
}