java版 使用spark机器学习包进行求平均数遇到类型转换出错

Question

问题：java版 使用spark机器学习包进行求平均数遇到：  java.lang.Double cannot be cast to org.apache.spark.mllib.linalg.Vector

//读取数据
        Dataset<Row> jdbcDF = spark.read()
                .option("url",url)
                .option("dbtable", table_name)
                .option("driver", "com.mysql.jdbc.Driver")
                .option("user",user)
                .option("password", password)
                .format("jdbc")
                .load();

JavaRDD<Vector> vectorJavaRDD = jdbcDF.toJavaRDD().mapPartitions(new FlatMapFunction<Iterator<Row>, Vector>() {
            public Iterator<Vector> call(Iterator<Row> iterator) throws Exception {

                List<Vector> results = new ArrayList<Vector>();

                while (iterator.hasNext()) {
                    Row row = iterator.next();
                    Vector vector = (Vector) row.getAs("temperature1");
                    results.add(new org.apache.spark.mllib.linalg.DenseVector(vector.toArray()));
                }

                return results.iterator();
            }
        });

        //  summary
        MultivariateStatisticalSummary summary = Statistics.colStats(vectorJavaRDD.rdd());
        Vector max = summary.max();
        System.out.println("max: "+ Arrays.toString(max.toArray()));
        System.out.println("min: "+Arrays.toString(summary.min().toArray()));
        System.out.println("count:" +summary.count());
        System.out.println("mean: "+Arrays.toString(summary.mean().toArray()));

问题是这行运行报错： Vector vector = (Vector) row.getAs("temperature1");

运行报错：java.lang.Double  cannot be cast to org.apache.spark.mllib.linalg.Vector