GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — Java/ciphers/Caesar.java at master · GitPointer/Java

Expand file tree

/

Caesar.java

Copy path
More file actions
More file actions

Latest commit

 

History

History
History
131 lines (105 loc) · 3.69 KB
/

Caesar.java

Copy path

File metadata and controls

131 lines (105 loc) · 3.69 KB
Raw
Copy raw file
Download raw file
Open symbols panel
Edit and raw actions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
package ciphers;
import java.util.Scanner;
/**
*
* A Java implementation of Caesar Cipher. /It is a type of substitution cipher
* in which each letter in the plaintext is replaced by a letter some fixed
* number of positions down the alphabet. /
*
* @author FAHRI YARDIMCI
* @author khalil2535
*/
public class Caesar {
/**
* Encrypt text by shifting every Latin char by add number shift for ASCII
* Example : A + 1 -> B
*
* @param message
* @param shift
* @return Encrypted message
*/
public static String encode(String message, int shift) {
String encoded = "";
shift %= 26;
final int length = message.length();
for (int i = 0; i < length; i++) {
// int current = message.charAt(i); //using char to shift characters because ascii is in-order latin alphabet
char current = message.charAt(i); // Java law : char + int = char
if (IsCapitalLatinLetter(current)) {
current += shift;
encoded += (char) (current > 'Z' ? current - 26 : current); // 26 = number of latin letters
} else if (IsSmallLatinLetter(current)) {
current += shift;
encoded += (char) (current > 'z' ? current - 26 : current); // 26 = number of latin letters
} else {
encoded += current;
}
}
return encoded;
}
/**
* Decrypt message by shifting back every Latin char to previous the ASCII
* Example : B - 1 -> A
*
* @param encryptedMessage
* @param shift
* @return message
*/
public static String decode(String encryptedMessage, int shift) {
String decoded = "";
shift %= 26;
final int length = encryptedMessage.length();
for (int i = 0; i < length; i++) {
char current = encryptedMessage.charAt(i);
if (IsCapitalLatinLetter(current)) {
current -= shift;
decoded += (char) (current < 'A' ? current + 26 : current);// 26 = number of latin letters
} else if (IsSmallLatinLetter(current)) {
current -= shift;
decoded += (char) (current < 'a' ? current + 26 : current);// 26 = number of latin letters
} else {
decoded += current;
}
}
return decoded;
}
/**
*
* @param c
* @return true if character is capital Latin letter or false for others
*/
private static boolean IsCapitalLatinLetter(char c) {
return c >= 'A' && c <= 'Z';
}
/**
*
* @param c
* @return true if character is small Latin letter or false for others
*/
private static boolean IsSmallLatinLetter(char c) {
return c >= 'a' && c <= 'z';
}
/**
*
* @deprecated TODO remove main and make JUnit Testing
*/
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Please enter the message (Latin Alphabet)");
String message = input.nextLine();
System.out.println(message);
System.out.println("Please enter the shift number");
int shift = input.nextInt() % 26;
System.out.println("(E)ncode or (D)ecode ?");
char choice = input.next().charAt(0);
switch (choice) {
case 'E':
case 'e':
System.out.println("ENCODED MESSAGE IS \n" + encode(message, shift)); //send our function to handle
break;
case 'D':
case 'd':
System.out.println("DECODED MESSAGE IS \n" + decode(message, shift));
}
}
}
You are visitor 01402503 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.