int[][] mat = {{1,6,2}, {7,3,1}, {1,2,5}};
        int[] vec = mat[mat.length];
        for(int i = 0; i < mat.length; i++) {
            int somatorio = 0;
            for(int p = 0; p < mat[i].length; p++)
                somatorio += mat[i][p];

            vec[i] = somatorio;
        }

        for(int i = 0; i < vec.length - 1; i++) {
            for(int p = 0; p < vec.length; p++) {
                if(vec[i] > vec[p]) { // Ordem decrescente
                    int tmp = vec[i];
                    vec[i] = vec[p];
                    vec[p] = tmp;

                    int[] vecTmp = mat[i];
                    mat[i] = mat[p];
                    mat[p] = vecTmp;
                }
            }
        }