A protocol stack is _____.
2 answers:
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Answer:
Check the explanation
Explanation:
MessageEncoder. java
public interface MessageEncoder
{
//single abstract method encode(plainText) where plainText is the message to be encoded.
public String encode(String plainText);
}//end interface
SubstitutionCipher. java
import java.util.Scanner;
public class SubstitutionCipher implements MessageEncoder, MessageDecoder
{
/**
The constructor should have 1 parameter called shift
*/
private int shift;
/**
Non-default constructor with one parameter
*/
public SubstitutionCipher(int numberSpaces)
{
shift = numberSpaces;
}//end non default constructor
/**
Define the method encode so that each letter is shifted by the value in shift
*/
public String encode(String plainText)
{
String cipherText = "";
for(int i = 0; i < plainText. length(); i++)
{
Character encodeLetter = plainText.charAt(i);
cipherText = cipherText + shift1Character(encodeLetter);
}//end for loop
return cipherText;
}//end encode method
/**
Define the method decode so that each letter is shifted by minus the value in shift
*/
public String decode(String cipherText)
{
String plainText = "";
for(int i = 0; i < cipherText. length(); i++)
{
Character decodeLetter = cipherText.charAt(i);
plainText = plainText + shift1CharacterBack(decodeLetter);
}//end for loop
return plainText;
}//end encode method
/**
Hint: You may wish to define a private method that shifts a single character
*/
private Character shift1Character(Character oneLetter)
{
return (char)(oneLetter + shift);
}//end method
/**
Hint: You may wish to define a private method that shifts a single character
back to its original position
*/
private Character shift1CharacterBack(Character oneLetter)
{
return (char)(oneLetter - shift);
}//end method
////////////////////////////////////////////////////////////////////////////////////////////////////////
public static void main(String[] args)
{
Scanner keyboard = new Scanner(System.in);
SubstitutionCipher shift3Places = new SubstitutionCipher(3);
System.out.println("Substituation method using caesar shift: \n");
String plainText = "I think I am finally back on track\n";
System.out.println("Plain text to be encoded: " + plainText);
String cipher = shift3Places.encode(plainText);
System.out.println("Cipher text after encoding: " + cipher);
SubstitutionCipher shiftMinus3 = new SubstitutionCipher(-3);
System.out.println("\n\nTime to decode the cipher now.\n");
String decoded = shiftMinus3. encode(cipher);
System.out.println("Decoded text after removing cipher: " + decoded);
////////////////////////////////////////////////////////////////////////////System.out.println("Testing the decode method.");
////////////////////////////////////////////////////////////////////////////decoded = shift3Places. decode(cipher);
////////////////////////////////////////////////////////////////////////////System.out.println("Text after decoding: " + decoded);
}//end main
}//end class
MessageDecoder. java
public interface MessageDecoder
{
//single abstract method decode(cipherText) where cipherText is the message to be decoded.
public String decode(String cipherText);
}//end interface
