matrix.java

package com.company;

import java.util.Scanner;

public class Matrix {
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        String source = scanner.nextLine();

        int width = 3;
        int height = 3;

        int charsPerMatrix = width * height;
        int matricesCount = source.length() / charsPerMatrix + (source.length() % charsPerMatrix > 0 ? 1 : 0);

        char[][][] matrices = new char[matricesCount][height][width];

        for (int i = 0; i < matricesCount; i++) {
            int length = charsPerMatrix;
            if(i == matricesCount - 1)
            {
                length = source.length() % charsPerMatrix;
            }
            char[][] matrix = toMatrix(source, width, height, i * charsPerMatrix, length);
            matrices[i] = matrix;
        }

        for (int i = 0; i < matricesCount; i++) {
            printMatrix(matrices[i]);
        }
    }

    public static void printMatrix(char[][] matrix) {

        for (int i = 0; i < matrix[0].length * 4 + 1; i++) {
            System.out.print('-');
        }
        System.out.println();

        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[i].length; j++) {
                System.out.print("| " + (matrix[i][j] == '\0' ? " " : matrix[i][j]) + " ");
            }
            System.out.println("|");

            for (int j = 0; j < matrix[0].length * 4 + 1; j++) {
                System.out.print('-');
            }
            System.out.println();
        }
        System.out.println();
    }

    public static char[][] toMatrix(String src, int width, int height, int startIndex, int length) {
        char[][] chars = new char[height][width];

        int cell = 0;

        for (int i = startIndex; i < startIndex + length; i++) {
            int row = cell / width;
            int col = cell % width;

            chars[row][col] = src.charAt(i);
            cell++;
        }

        return chars;
    }
}