Scala Example Code

Function

In Spark application, call Hive API using Spark to operate Hive table, analyze the data, and then write the analyzed data to the HBase table.

Example Code

For details about code, see com.huawei.bigdata.spark.examples.SparkHbasetoHbase.

Example code

/**
  * calculate data from hive/hbase,then update to hbase
  */
object SparkHivetoHbase {

  case class FemaleInfo(name: String, gender: String, stayTime: Int)

  def main(args: Array[String]) {

    // Obtain the data in the table through the Spark interface.

    val spark = SparkSession
      .builder()
      .appName("SparkHiveHbase")
      .config("spark.sql.warehouse.dir", "spaek-warehouse")
      .enableHiveSupport()
      .getOrCreate()

    import spark.implicits._
    val dataFrame = spark.sql("select name, account from person")

    // Traverse every Partition in the hive table and update the hbase table
    // If less data, you can use rdd.foreach()
    dataFrame.rdd.foreachPartition(x => hBaseWriter(x))

    spark.stop()
  }

  /**
    * write to hbase table in exetutor
    *
    * @param iterator partition data from hive table
    */
  def hBaseWriter(iterator: Iterator[Row]): Unit = {
    // read hbase
    val tableName = "table2"
    val columnFamily = "cf"
    val conf = HBaseConfiguration.create()

    var table: Table = null
    var connection: Connection = null

    try {
      connection = ConnectionFactory.createConnection(conf)
      table = connection.getTable(TableName.valueOf(tableName))

      val iteratorArray = iterator.toArray
      val rowList = new util.ArrayList[Get]()
      for (row <- iteratorArray) {
        val get = new Get(row.getString(0).getBytes)
        rowList.add(get)
      }

      // get data from hbase table
      val resultDataBuffer = table.get(rowList)

      // set data for hbase
      val putList = new util.ArrayList[Put]()
      for (i <- 0 until iteratorArray.size) {
        // hbase row
        val resultData = resultDataBuffer(i)
        if (!resultData.isEmpty) {
          // get hiveValue
          var hiveValue = iteratorArray(i).getInt(1)

          // get hbaseValue by column Family and colomn qualifier
          val hbaseValue = Bytes.toString(resultData.getValue(columnFamily.getBytes, "cid".getBytes))
          val put = new Put(iteratorArray(i).getString(0).getBytes)

          // calculate result value
          val resultValue = hiveValue + hbaseValue.toInt

          // set data to put
          put.addColumn(Bytes.toBytes(columnFamily), Bytes.toBytes("cid"), Bytes.toBytes(resultValue.toString))
          putList.add(put)
        }
      }

      if (putList.size() > 0) {
        table.put(putList)
      }
    } catch {
      case e: IOException =>
        e.printStackTrace();
    } finally {
      if (table != null) {
        try {
          table.close()
        } catch {
          case e: IOException =>
            e.printStackTrace();
        }
      }
      if (connection != null) {
        try {
          //Close the HBase connection.
          connection.close()
        } catch {
          case e: IOException =>
            e.printStackTrace()
        }
      }
    }
  }

}