通过为包含JSON的列定义模式来创建配置单元表的视图

2. 我已经在配置单元上为HDFS文件夹创建了一个外部表

卡夫卡流到HDFS

public static void main(String[] args) throws Exception {

    String brokers = "quickstart:9092";
    String topics = "simple_topic_6";
    String master = "local[*]";

    SparkSession sparkSession = SparkSession
            .builder().appName(EventKafkaToParquet.class.getName())
            .master(master).getOrCreate();
    SQLContext sqlContext = sparkSession.sqlContext();
    SparkContext context = sparkSession.sparkContext();
    context.setLogLevel("ERROR");

    Dataset<Row> rawDataSet = sparkSession.readStream()
            .format("kafka")
            .option("kafka.bootstrap.servers", brokers)
            .option("subscribe", topics).load();
    rawDataSet.printSchema();

    rawDataSet = rawDataSet.withColumn("employee", rawDataSet.col("value").cast(DataTypes.StringType));
    rawDataSet.createOrReplaceTempView("basicView");
    Dataset<Row> writeDataset = sqlContext.sql("select employee from basicView");
    writeDataset
            .repartition(1)
            .writeStream()
            .option("path","/user/cloudera/employee/")
            .option("checkpointLocation", "/user/cloudera/employee.checkpoint/")
            .format("parquet")
            .trigger(Trigger.ProcessingTime(5000))
            .start()
            .awaitTermination();
}

配置单元上的外部表

CREATE EXTERNAL TABLE employee_raw ( employee STRING )  
STORED AS PARQUET
LOCATION '/user/cloudera/employee' ;

firstName, lastName, street, city, state, zip

hive> select * from employee_raw;
OK
{"employee":{"firstName":"Ganesh","lastName":"Kumar","address":{"street":"1400 Dakota Dr","city":"Princeton","state":"NJ","zip":"09800"}}}
{"employee":{"firstName":"Ganesh","lastName":"Kumar","address":{"street":"1400 Dakota Dr","city":"Princeton","state":"NJ","zip":"09800"}}}
{"employee":{"firstName":"Ganesh","lastName":"Kumar","address":{"street":"1400 Dakota Dr","city":"Princeton","state":"NJ","zip":"09800"}}}
{"employee":{"firstName":"Ganesh","lastName":"Kumar","address":{"street":"1400 Dakota Dr","city":"Princeton","state":"NJ","zip":"09800"}}}
{"employee":{"firstName":"Ganesh","lastName":"Kumar","address":{"street":"1400 Dakota Dr","city":"Princeton","state":"NJ","zip":"09800"}}}
Time taken: 0.123 seconds, Fetched: 5 row(s)

感谢您的意见