Thread: Encrypting a text message

I need to encrypt a text message in a two dimensional array(closest square matrix to number of letters in the text message) putting each letter that comes first in the first row, then second row... etc

It is not working and I don't understand the error messages.

public class CaesarBox {
 
	public static void main(String[] args) {
		// CaesarsBox <-encrypt|-decrypt> 
 
		if(args[0].equals("-encrypt")){
			System.out.println(encrypt(args[1]));
		}
 
	}
 
	public static String encrypt(String plainText) {
 
 
	String s = plainText.toLowerCase();// Taking out upper cases
 
	s = s.replaceAll("\\s","");//Taking out blank spaces
 
	 char [] Arr = s.toCharArray();//Convert from string to array of characters
 
	float squareRoot = (float) Math.sqrt(s.length());
 
	int dimension = (int) Math.ceil(squareRoot);
 
	int x = dimension;
 
	char[][] box = new char [x][x];// This is the box: a 2 dimensional array
 
	int counter = 0;
 
	for(int i = 0; i<x; i++){
 
		for(int j = 0; j<x; j++){
 
				box[i][j]= Arr[counter];
 
				counter++;
			}
		}
 
 
    System.out.print(box);
 
	return s;
	}	
}

Errors:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 32
at CaesarBox.encrypt(CaesarBox.java:39)
at CaesarBox.main(CaesarBox.java:11)

Originally Posted by dianac

It is not working and I don't understand the error messages.

Any time you have an exception, type the exception into your favorite search engine. Once you understand java.lang.ArrayIndexOutOfBoundsException look at the code again for what may be the cause.
Ask more questions if necessary.

Where is favorite search engine? I use Eclipse

doesnt he mean a search engine such as google ?

Originally Posted by mist4lyf

doesnt he mean a search engine such as google ?

Yes, I apologize for the confusion.

java.lang.ArrayIndexOutOfBoundsException
...indicate that an array has been accessed with an illegal index...

Thanks, but I have been looking to the code and can't see what this out of bounds is.

I have modified the code to:

public class CaesarBox {
 
	public static void main(String[] args) {
		// CaesarsBox <-encrypt|-decrypt> 
 
		if(args[0].equals("-encrypt")){
			System.out.println(encrypt(args[1]));
		}
 
	}
 
	public static String encrypt(String plainText) {
 
 
	String s = plainText.toLowerCase();// Taking out upper cases
 
	s = s.replaceAll("\\s","");//Taking out blank spaces
 
	float squareRoot = (float) Math.sqrt(s.length());
 
	int dimension = (int) Math.ceil(squareRoot);
 
	int x = dimension;
 
	char[][] box = new char [x][];// This is the box: a 2 dimensional array
 
	int counter = 0;
 
	for(int i = 0; i<x; ++i){
 
		for(int j = 0; j<x; ++j){
 
				box[i][j]= s.charAt(counter);
 
				counter++;
			}
 
		}
 
 
    System.out.print(box);
 
	return s;
	}	
}

The problem is in:box[i][j]= s.charAt(counter);

And I don't get how this is out of bounds. Can anyone help me see it?

Thanks, fixed it. The problem now is the size of the box keeps showing up as 6 and it should be a 2 dimensional array 6 x 6

 
public class CaesarBox {
 
	public static void main(String[] args) {
		// CaesarsBox <-encrypt|-decrypt> 
 
		if(args[0].equals("-encrypt")){
			System.out.println(encrypt(args[1]));
		}
 
	}
 
	public static String encrypt(String plainText) {
 
 
	String s = plainText.toLowerCase();// Taking out upper cases
 
	s = s.replaceAll("\\s","");//Taking out blank spaces
 
	float squareRoot = (float) Math.sqrt(s.length());
 
	int dimension = (int) Math.ceil(squareRoot);
 
	int x = dimension;
 
	int y = dimension;
 
	char[][] box = new char [x][y];// This is the box: a 2 dimensional array
 
	System.out.println(box.length);
 
	int counter = 0;
 
	for(int i = 0; i<x; i++){
 
		for(int j = 0; j<y; j++){
 
           box[i][j]= s.charAt(counter);
 
				if(counter<31){
					counter++;
 
					System.out.println(box[i][j]);
				}
			}
 
		}
 
	System.out.println(box);
 
	return s;
	}	
}

What could be wrong?

box[i] is 6
s size is 32

The problem is that box is printing a one dimensional array

--- Update ---

is being printed as one dimensional array

The exception was already fixed.


i say one dimension array, because it is printing all in one row

 
 
 
public class CaesarBox {
 
	public static void main(String[] args) {
		// CaesarsBox <-encrypt|-decrypt> 
 
		if(args[0].equals("-encrypt")){
			System.out.println(encrypt(args[1]));
		}
 
	}
 
	public static String encrypt(String plainText) {
 
 
	String s = plainText.toLowerCase();// Taking out upper cases
 
	s = s.replaceAll("\\s","");//Taking out blank spaces
 
	float squareRoot = (float) Math.sqrt(s.length());
 
	int dimension = (int) Math.ceil(squareRoot);
 
	int x = dimension;
 
	int y = dimension;
 
	char[][] box = new char [x][y];// This is the box: a 2 dimensional array
 
 
	int counter = 0;
 
	for(int i = 0; i<x; i++){
 
		for(int j = 0; j<y; j++){
 
           box[i][j]= s.charAt(counter);
 
				if(counter<31){
					counter++;					
				}
				System.out.print(box[i][j]);	
			}
 
		}
 
 
 
	return s;
	}	
}

printing box[i][j] is returning
alongtimeagoinagalaxyfar,farawayyyyyalongtimeagoin agalaxyfar,faraway



and args[1] is "A long time ago in a galaxy far, far away"

It is working but the output is not the desired.

Box should be printing

a l o n g t
i m e a g o
, i n a g a
l a x y f a
r , f a r a
w a y

and it is printing alongtimeagoinagalaxyfar,farawayyyyyalongtimeagoin agalaxyfar,faraway

What if I want to print box each row in one line?

The is dued to return s in the code. This method requires me to return a string. But when I try to return box it does not allow me, because it is not a string.

I need to return the encrypted string called box, but it keeps showing error

public class CaesarBox {
 
	public static void main(String[] args) {
		// CaesarsBox <-encrypt|-decrypt> 
 
		if(args[0].equals("-encrypt")){
			System.out.println(encrypt(args[1]));
		}
 
	}
 
	public static String encrypt(String plainText) {
 
 
	String s = plainText.toLowerCase();// Taking out upper cases
 
	s = s.replaceAll("\\s","");//Taking out blank spaces
 
	float squareRoot = (float) Math.sqrt(s.length());
 
	int dimension = (int) Math.ceil(squareRoot);
 
	int x = dimension;
 
	int y = dimension;
 
	char[][] box = new char [x][y];// This is the box: a 2 dimensional array
 
 
	int counter = 0;
 
	for(int i = 0; i<x; i++){
 
		for(int j = 0; j<y; j++){
 
           box[i][j]= s.charAt(counter);
 
				if(counter<31){
					counter++;	
				}	
			}
 
		}
	System.out.println( java.util.Arrays.deepToString(box));
 
	return box ;
	}
 
}

is there a full solution to this problem? i'm struggling so bad

The output should be

a l o n g t
i m e a g o
, i n a g a
l a x y f a
r , f a r a
w a y

and it is returning

[[a, l, o, n, g, t], [i, m, e, a, g, o], [i, n, a, g, a, l], [a, x, y, f, a, r], [,, f, a, r, a, w], [a, y, y, y, y, y]]

public class CaesarBox {
 
	public static void main(String[] args) {
		// CaesarsBox <-encrypt|-decrypt> 
 
		if(args[0].equals("-encrypt")){
			System.out.println(encrypt(args[1]));
		}
 
	}
 
	public static String encrypt(String plainText) {
 
 
	String s = plainText.toLowerCase();// Taking out upper cases
 
	s = s.replaceAll("\\s","");//Taking out blank spaces
 
	float squareRoot = (float) Math.sqrt(s.length());
 
	int dimension = (int) Math.ceil(squareRoot);
 
	int x = dimension;
 
	int y = dimension;
 
	char[][] box = new char [x][y];// This is the box: a 2 dimensional array
 
 
	int counter = 0;
 
	for(int i = 0; i<x; i++){
 
		for(int j = 0; j<y; j++){
 
           box[i][j]= s.charAt(counter);
 
				if(counter<31){
					counter++;	
 
				}	
 
			}
 
		}
	String encrypt = java.util.Arrays.deepToString(box);
 
	return encrypt ;
	}
 
}

What could be wrong?

I know, just was looking how to convert it to string. Already solved, thanks.