/**

* Java. Level 2. Lesson 2. Example of homework

*

* @author Sergey Iryupin

* @version 0.3.2 dated Jun 11, 2018

*/

import java.io.*;

import java.util.Arrays;

class HW2Lesson {

static final int SIZE = 4;

static final String[] DATA = {

"1 3 1 2\n2 3 2 2\n5 6 7 1\n3 3 1 0",

"1 3 1 2\n2 a 2 2\n5 6 7 1\n3 3 1 0",

"1 3 1 2\n2 3 2 2\n5 6 7 1",

"1 3 1 2\n2 3 2 2\n5 6 7 1\n3 3 1"};

static final String FILE_NAME = "lesson2test.txt";

public static void main(String[] args) {

// reading from file to buffer

StringBuffer buffer = new StringBuffer();

try (BufferedReader reader = new BufferedReader(

new FileReader(FILE_NAME))) {

while (reader.ready())

buffer.append(reader.readLine() + "\n");

} catch (IOException ex) {

System.out.println(ex.getMessage());

}

// processing the data from buffer

if (buffer.length() > 0)

try {

System.out.println(calcMatrix(strToMatrix(buffer.toString())));

} catch (NumberFormatException | ArrayIndexOutOfBoundsException ex) {

System.out.println(ex.getMessage());

}

// processing strings from DATA

for (String str : DATA)

try {

System.out.println(calcMatrix(strToMatrix(str)));

} catch (NumberFormatException | ArrayIndexOutOfBoundsException ex) {

System.out.println(ex.getMessage());

}

}

static String[][] strToMatrix(String str) { // convert String into Matrix

String[] lines = str.split("\n");

String[][] matrix = new String[lines.length][];

for (int i = 0; i < lines.length; i++) {

matrix[i] = lines[i].split("\\s+");

System.out.println(Arrays.toString(matrix[i]));

}

return matrix;

}

static int calcMatrix(String[][] matrix)

throws NumberFormatException, ArrayIndexOutOfBoundsException {

int result = 0;

// checking the number of rows

if (matrix == null || matrix.length != SIZE)

throw new ArrayIndexOutOfBoundsException(

"The number of rows doesn't match");

// processing the matrix

for (int i = 0; i < matrix.length; i++) {

if (matrix[i] == null ||

matrix[i].length != SIZE) // checking the number of columns

throw new ArrayIndexOutOfBoundsException(

"The number of colums in row " + (i+1) + " doesn't match");

for (int j = 0; j < matrix[i].length; j++)

try {

result += Integer.parseInt(matrix[i][j]);

} catch (NumberFormatException ex) {

throw new NumberFormatException(

"Bad symbol(s) in row " + (i+1) + " column " + (j+1));

}

}

return result;

}

}