Algoritma CAESAR CHPPER Dengan Bahasa Java


//medidarmawan
import java.util.*;
class CaesarCipher
{
public static void main(String args[])
{
Scanner sc=new Scanner(System.in);
int shift,i,n;
String str;
String str1="";
String str2="";
System.out.println("MASUKAN PLAINTEKS : ");
str=sc.nextLine();
str=str.toLowerCase();
n=str.length();
char ch1[]=str.toCharArray();
char ch3,ch4;
System.out.println("MASUKAN KEY : ");
shift=sc.nextInt();
System.out.println();
System.out.println("ENKRIPSI TEKS : ");
for(i=0;i<n;i++)
{
if(Character.isLetter(ch1[i]))
{
ch3=(char)(((int)ch1[i]+shift-97)%26+97);
//System.out.println(ch1[i]+" = "+ch3);
str1=str1+ch3;
}
else if(ch1[i]==' ')
{
str1=str1+ch1[i];
}
}
System.out.println(str1);
System.out.println();
System.out.println("DESKRISI TEXT DARI HASIL ENKRIPSI : ");
char ch2[]=str1.toCharArray();
for(i=0;i<str1.length();i++)
{
if(Character.isLetter(ch2[i]))
{
if(((int)ch2[i]-shift)<97)
{
ch4=(char)(((int)ch2[i]-shift-97+26)%26+97);
}
else
{
ch4=(char)(((int)ch2[i]-shift-97)%26+97);
}
str2=str2+ch4;
}
else if(ch2[i]==' ')
{
str2=str2+ch2[i];
}
}
System.out.println(str2);
}
}
TERIMA KASIH
Semoga bermanfaat :)
@medidarmawan
@md_skyart