CosineSimilarity [on hold]

I want to caculate the similarity in rows of a matrix such as D, but the results are not correct!! What is the problem of my codes?

private ArrayList cosineSimilarity(int rowIndex, Matrix D) {

    double dotProduct = 0.0, firstNorm = 0.0, secondNorm = 0.0;
    double cosinSimilarity;
    ArrayList<Double> similarRows = new ArrayList<>();

    for(int row = 0; row < D.getRowDimension(); row++){
        for (int column = 0; column < D.getColumnDimension(); column++) {
        dotProduct = + (D.get(rowIndex, column) * D.get(row, column));
        firstNorm =  + pow(D.get(rowIndex, column),2);
        secondNorm = + pow(D.get(row, column), 2);
       // Matrix f = D.getMatrix(row, column);
        }
        cosinSimilarity = (dotProduct / (sqrt(firstNorm) * sqrt(secondNorm)));
        similarRows.add(row, cosinSimilarity);
    }