- Students must develop the code required to create a square two-dimensional array just large enough...

- Students must develop the code required to create a square two-dimensional array just large enough to store a given string in encrypted form using the given encryption algorithm. The character used after the end of the encrypted string is the ASCII delete key, set as final UNPRINTABLE_CHAR_VALUE. After this value is stored, the encryption process fills the remaining elements with random values

- Students must develop the code to decrypt a given square two-dimensional array and using the given encryption algorithm

- Students must develop other supporting methods as specified (below) to manage the encryption operations*

- Students will also document all classes and methods using the Javadoc commenting process; comments are not required to be exactly the same as found in the supporting document (below) but they should be semantically equivalent

- Students will upload the EncryptionClass.java file to this assignment; any other uploaded files will result in a reduction of the project grade, and in some cases, may cause a complete loss of credit

- Assignment Specification (Javadoc output for the project):

p1_package

Class EncryptionClass

java.lang.Object
- p1_package.EncryptionClass

FileIoToolsForEncryptionClass.java

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class EncryptionClass
   {/**
     * Constant for maximum input char limit
     */
    private final int MAX_INPUT_CHARS = 256;

    /**
     * Constant for unprintable char value used as message end char
     */
    private final int UNPRINTABLE_CHAR_VALUE = 127; // ASCII for delete key

    /**
     * Constant for minus sign used in getAnInt
     */
    private final char MINUS_SIGN = '-';

    /**
     * Class Global FileReader variable so methods can be used
     */
    private FileReader fileIn;

    /**
     * Downloads encrypted data to file
     * <p>
     * Note: No action taken if array is empty
     * @param fileName String object holding file name to use
     */
    void downloadData( String fileName )
       {FileWriter toFile;
        int rowIndex, colIndex;
        if( arrSide > 0 )
           {
            try
               {
                toFile = new FileWriter( fileName );
                toFile.write( "" + arrSide + "\r\n" );
                for( rowIndex = 0; rowIndex < arrSide; rowIndex++ )
                   {
                    for( colIndex = 0; colIndex < arrSide; colIndex++ )
                       {
                        if( encryptedArr[ rowIndex ][ colIndex ] < 100 )
                           {
                            toFile.write( "0" );
                           }
                        toFile.write(" "+ encryptedArr[ rowIndex ][ colIndex ] + " " );
                       }
                    toFile.write( "\r\n" );
                   }

                toFile.flush();
                toFile.close();
               }
            catch( IOException ioe )
               {
                ioe.printStackTrace();
               }
           }
       }

    /**
     * gets an integer from the input stream
     *
     * @param maxLength maximum length of characters
     * input to capture the integer
     *
     * @return integer captured from file
     */
    private int getAnInt( int maxLength )
       {
        int inCharInt;
        int index = 0;
        String strBuffer = "";
        int intValue;
        boolean negativeFlag = false;

        try
           {
            inCharInt = fileIn.read();

            // clear space up to number
            while( index < maxLength && !charInString( (char)inCharInt,
                                                           "0123456789+-" ) )
               {
                inCharInt = fileIn.read();
                index++;
               }
            if( inCharInt == MINUS_SIGN )
               {
                negativeFlag = true;
                inCharInt = fileIn.read();
               }

            while( charInString( (char)inCharInt, "0123456789" ) )
               {
                strBuffer += (char)( inCharInt );

                index++;

                inCharInt = fileIn.read();
               }
           }

        catch( IOException ioe )
           {
            System.out.println( "INPUT ERROR: Failure to capture character" );
            strBuffer = "";
           }

        intValue = Integer.parseInt( strBuffer );

        if( negativeFlag )
           {
            intValue *= -1;
           }

        return intValue;
       }

    /**
     * Uploads data from file holding a square array
     *
     * @param fileName String object holding file name
     */
    void uploadData( String fileName )
       {
        int rowIndex, colIndex;

        try
           {
            // Open FileReader
            fileIn = new FileReader( fileName );

            // get side length
            arrSide = getAnInt( MAX_INPUT_CHARS );

            encryptedArr = new int[ arrSide ][ arrSide ];

            for( rowIndex = 0; rowIndex < arrSide; rowIndex++ )
               {
                for( colIndex = 0; colIndex < arrSide; colIndex++ )
                   {
                    encryptedArr[ rowIndex ][ colIndex ]
                                                  = getAnInt( MAX_INPUT_CHARS );
                   }
               }

            fileIn.close();
           }

        // for opening file
        catch( FileNotFoundException fnfe )
           {
            fnfe.printStackTrace();
           }

        // for closing file
        catch (IOException ioe)
           {
            ioe.printStackTrace();
           }
       }
   }

Expert Solution

p1_package

Class EncryptionClass

java.lang.Object
- p1_package.EncryptionClass