Class SubstitutionMessage

Object

OpenMessage

SubstitutionMessage

All Implemented Interfaces:

EncryptedMessage, Message

public class SubstitutionMessage
extends OpenMessage
implements EncryptedMessage

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	ALPHABET
protected Key	messageKey	Note that all you need to declare here is messageKey, as to, from, subject, and body are handled in OpenMessage, which SubstitutionMessage inherits fom.

Fields inherited from class OpenMessage

body, from, subject, to

Constructor Summary

Constructors

Constructor	Description
SubstitutionMessage(String to, String from, String subject, String body, Key key)

Method Summary

Modifier and Type	Method	Description
String	decrypt(String message, Key key)	Decrypts the String passed in.
String	encrypt(String message, Key key)	Encrypts the String passed into it using a Substitution Cipher.

Methods inherited from class OpenMessage

getBody, getFrom, getSubject, getTo, search, searchFrom, searchSubject, searchTo, toString

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

messageKey

protected Key messageKey

Note that all you need to declare here is messageKey, as to, from, subject, and body are handled in OpenMessage, which SubstitutionMessage inherits fom.

ALPHABET

private static final String ALPHABET

See Also:

• Constant Field Values

Constructor Details

SubstitutionMessage

public SubstitutionMessage(String to,
 String from,
 String subject,
 String body,
 Key key)

Method Details

encrypt

public String encrypt(String message,
 Key key)

Encrypts the String passed into it using a Substitution Cipher. Any characters that aren't in the ALPHABET variable will not be encrypted, they will remain the original character.

Example output:

           Key key = new Key("cheshirecat", "2pHZWoYd8cTbJ0n1fmeyOs6Buk4VX5i3hvQKzD)GgUPF9xjISRLwl.ANaM(rE7tq?C", "S");
           Key key2 = new Key("alice", "AMivN0z3qwVcTH4W9xsEGjhJ2tlDp(5uLoFRg8r.fXOQP6Ym?Ie)dky7UKC1bZSanB", "S");
           SubstitutionMessage message1 = new SubstitutionMessage("Cheshire Cat", "Quick Rabbit", "Important Meeting", "Don't be late for our very important date!", key);
           SubstitutionMessage message2 = new SubstitutionMessage("Alice", "Hatter", "Celebration", "Happy Un-Birthday!!!", key2);
           System.out.println(message1.encrypt(message1.getBody(), key));
           System.out.println(message2.encrypt(message2.getBody(), key2));
           

• First line prints ZgG'x Vi D4xi 3gF gjF IiFL Q)UgFx4Gx 54xi!
• Second line prints 3lXXe G.-MFQ6o(le!!!

Specified by:

encrypt in interface EncryptedMessage

Parameters:

message - String to encrypt

key - Key used to encrypt the message

Returns:

String containing encrypted message

decrypt

public String decrypt(String message,
 Key key)

Decrypts the String passed in.

Example output:

           Key key = new Key("cheshirecat", "2pHZWoYd8cTbJ0n1fmeyOs6Buk4VX5i3hvQKzD)GgUPF9xjISRLwl.ANaM(rE7tq?C", "S");
           Key key2 = new Key("alice", "AMivN0z3qwVcTH4W9xsEGjhJ2tlDp(5uLoFRg8r.fXOQP6Ym?Ie)dky7UKC1bZSanB", "S");
           SubstitutionMessage message1 = new SubstitutionMessage("Cheshire Cat", "Quick Rabbit", "Important Meeting", "Don't be late for our very important date!", key);
           SubstitutionMessage message2 = new SubstitutionMessage("Alice", "Hatter", "Celebration", "Happy Un-Birthday!!!", key2);
           String encryptedMessage1 = "ZgG'x Vi D4xi 3gF gjF IiFL Q)UgFx4Gx 54xi!";
           String encryptedMessage2 = "3lXXe G.-MFQ6o(le!!!";
           System.out.println(message1.decrypt(encryptedMessage1, key));
           System.out.println(message2.decrypt(encryptedMessage2, key2));
           

• First line prints Don't be late for our very important date!
• Second line prints Happy Un-Birthday!!!

Specified by:

decrypt in interface EncryptedMessage

Parameters:

message - String to decrypt

key - Key used to decrypt the message

Returns:

String containing decrypted message