Matrices in java ()

In a Matrix the moment I enter a number for example one (1) the rest of the row is filled in at zero. ç

public Bidimensional (int f, int c){
      mat= new int [f][c];
}
    public int[][] matriz ( int col,int fil){
        for (int i = 0; i < 4; i++) {
            for (int j = 0; j < col; j++) {

             mat[i][j] =Integer.parseInt( JOptionPane.showInputDialog("Ingrese su voto para el canditado " + "A[" + i + "][" + j + "] " ));

            }
        }
        return mat;
    }