Java Generics and numbers

Question

In an attempt to see if I can clean up some of my math code, mostly matrix stuff, I am trying to use some Java Generics. I have the following method:

private <         


        

Answer 1

 T[][] zeroMatrix(Class of, int row, int col) {
    T[][] matrix = (T[][]) java.lang.reflect.Array.newInstance(of, row, col);
    T zero = (T) of.getConstructor(String.class).newInstance("0");
    // not handling exception      

    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; 
            matrix[i][j] = zero;
        }
    }

    return matrix;
}

usage:

    BigInteger[][] bigIntegerMatrix = zeroMatrix(BigInteger.class, 3, 3);
    Integer[][] integerMatrix = zeroMatrix(Integer.class, 3, 3);
    Float[][] floatMatrix = zeroMatrix(Float.class, 3, 3);
    String[][] error = zeroMatrix(String.class, 3, 3); // <--- compile time error
    System.out.println(Arrays.deepToString(bigIntegerMatrix));
    System.out.println(Arrays.deepToString(integerMatrix));
    System.out.println(Arrays.deepToString(floatMatrix));

EDIT

a generic matrix:

public static  T[][] fillMatrix(Object fill, int row, int col) {
    T[][] matrix = (T[][]) Array.newInstance(fill.getClass(), row, col);

    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; j++) {
            matrix[i][j] = (T) fill;
        }
    }

    return matrix;
}    

Integer[][] zeroMatrix = fillMatrix(0, 3, 3); // a zero-filled 3x3 matrix
String[][] stringMatrix = fillMatrix("B", 2, 2); // a B-filled 2x2 matrix