我有下面的代码，我想写进Cassandra使用Spark2.4结构化流foreachbatch

Dataset<Row> df = spark
                .readStream()
                .format("kafka")
                .option("kafka.bootstrap.servers", "localhost:9092")
                .option("subscribe", "topic1")
                .load();
        Dataset<Row> values=df.selectExpr(
                "split(value,',')[0] as field1",
                "split(value,',')[1] as field2",
                "split(value,',')[2] as field3",
                "split(value,',')[3] as field4",
                "split(value,',')[4] as field5");
//TODO write into cassandra 
values.writeStream().foreachBatch(
                    new VoidFunction2<Dataset<String>, Long> {
                public void call(Dataset<String> dataset, Long batchId) {
                    // Transform and write batchDF
            }
            ).start();