Ovviamente solo una bozza migliorabile:

codice:
public class Matrix {

	private String[][] matrix = null;

	public Matrix() {
	}

	public Matrix(String[][] matrix) {
		this.matrix = matrix;
	}

	public Matrix getSubMatrix(int row, int column, int width, int height) {
		try {
			int r0 = matrix.length - row > height ? height : matrix.length - row;
			int c0 = matrix.length - column > width ? width : matrix.length - column;
			String[][] m = new String[r0][c0];
			for (int r = 0; r < m.length; r++) {
				for (int c = 0; c < m[0].length; c++) {
					m[r][c] = matrix[row + r][column + c];
				}
			}
			return new Matrix(m);
		} catch (Exception e) {
			return new Matrix();
		}
	}

	public String getValue(int row, int column) {
		try {
			return matrix[row][column];
		} catch (Exception e) {
			return "";
		}
	}

	public void setValue(int row, int column, String value) {
		try {
			matrix[row][column] = value;
		} catch (Exception e) {
		}
	}

	public int getRows() {
		try {
			return matrix.length;
		} catch (Exception e) {
			return 0;
		}
	}

	public int getColumns() {
		try {
			return matrix[0].length;
		} catch (Exception e) {
			return 0;
		}
	}

	@Override
	public String toString() {
		StringBuffer sb = new StringBuffer("");
		try {
			for (int r = 0; r < matrix.length; r++) {
				sb.append("[");
				for (int c = 0; c < matrix[0].length; c++) {
					sb.append("[" + matrix[r][c] + "]");
				}
				sb.append("]");
			}
		} catch (Exception e) {
			sb.append("[]");
		}
		return sb.toString();
	}

	public static void main(String[] args) {
		String[][] matrix = {
				{"00", "01", "02", "03", "04"}, 
				{"10", "11", "12", "13", "14"}, 
				{"20", "21", "22", "23", "24"}, 
				{"30", "31", "32", "33", "34"}, 
				{"40", "41", "42", "43", "44"} 
		};

		Matrix m = new Matrix(matrix);

		int n = 2;

		int rLimit = (int) Math.ceil((double) m.getRows() / (double) n);
		int cLimit = (int) Math.ceil((double) m.getColumns() / (double) n);

		for (int r = 0, rr = 0; r < rLimit; r++, rr += n) {
			for (int c = 0, cc = 0; c < cLimit; c++, cc += n) {
				Matrix sm = m.getSubMatrix(rr, cc, n, n);
				System.out.println(sm);
			}
		}
	}

}