需要使用java将apache spark中的Dataframe 1数据推送到空Dataframe 2数据

在这里，我需要将特定数据从dataframe1推送到空dataframe2，但我面临着麻烦。下面是代码

 public class PrintValue {
                public static void main(String[] args) {
                System.setProperty("hadoop.home.dir", "C:\\winutils");
                JavaSparkContext sc = new JavaSparkContext(newSparkConf().setAppName("JoinFunctions").setMaster("local[*]"));
                SQLContext sqlContext = new SQLContext(sc);
                SparkSession spark = SparkSession.builder().appName("JavaTokenizerExample").getOrCreate();

                JaroWinkler jw = new JaroWinkler();

                List<Row> data = Arrays.asList(
                RowFactory.create(1,"Hi I heard about Spark"),
                RowFactory.create(2,"I wish Java could use case classes"),
                RowFactory.create(3,"Logistic,regression,models,are,neat"));

                StructType schema = new StructType(new StructField[] {
                new StructField("label", DataTypes.IntegerType, false,
                  Metadata.empty()),
                new StructField("sentence", DataTypes.StringType, false,
                Metadata.empty()) });
                Dataset<Row> DataFrame1 = spark.createDataFrame(data, schema);
                sentenceDataFrame.show();


                List<Row> data1 = Arrays.asList();
                StructType schema2 = new StructType(new StructField[] {
                new StructField("label2", DataTypes.IntegerType, false,Metadata.empty()),
                new StructField("sentence2", DataTypes.StringType, false,Metadata.empty()) });
                Dataset<Row> DataFrame1 = spark.createDataFrame(sc.emptyRDD(), schema2);
                sentenceDataFrame1.show();

DataFrame1
+-----+--------------------+
|label|            sentence|
+-----+--------------------+
|    1|Hi I heard about ...|
|    2|I wish Java could...|
|    3|Logistic,regressi...|
+-----+--------------------+

DataFrame2
+-----+--------------------+
|label2|         sentence2  |
+-----+--------------------+
|     |                    |
|    2|I wish Java could...|
|     |                    |
+-----+--------------------+