如何将数据流数据（json）存储到cassandra中？

我得到的数据流（json）是这样的

       val topics= "test"
       val zkQuorum="localhost:2181"
       val group="test-consumer-group"    
       val sparkConf = new org.apache.spark.SparkConf()
          .setAppName("XXXXX")
          .setMaster("local[*]")
          .set("cassandra.connection.host", "127.0.0.1")
          .set("cassandra.connection.port", "9042")

        val ssc = new StreamingContext(sparkConf, Seconds(2))
        ssc.checkpoint("checkpoint")
        val topicMap = topics.split(",").map((_, numThreads.toInt)).toMap

        val lines = KafkaUtils.createStream(ssc, zkQuorum, group, topicMap).map(_._2)

通过上面的这个程序，我得到了DStream中的json数据。

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我将如何处理此数据流数据并将其存储到Cassandra或elastic search中？然后我将如何从数据流（json格式）检索数据并存储在Cassandra中？

您需要导入

com.datasax.spark.connector.\u

，将数据流的元素转换为适当的案例类

[{"id":100,"firstName":"Beulah","lastName":"Fleming","gender":"female","ethnicity":"SpEd","height":167,"address":27,"createdDate":1494489672243,"lastUpdatedDate":1494489672244,"isDeleted":0},{"id":101,"firstName":"Traci","lastName":"Summers","gender":"female","ethnicity":"Frp","height":181,"address":544,"createdDate":1494510639611,"lastUpdatedDate":1494510639611,"isDeleted":0}]

并使用隐式函数saveToCassandra保存它

case class Record(id: String, firstName: String, ...)
val colums = SomeColums("id", "first_name", ...)
val mapped = lines.map(whateverDataYouHave => fuctionThatReutrnsARecordObject)

有关更多信息，请查看文档

mapped.saveToCassandra(KEYSPACE_NAME, TABLE_NAME, columns)