Spark-Avro学习1之使用SparkSQL读取AVRO文件

更多Spark学习examples代码请见：https://github.com/xubo245/SparkLearning

1.安装：

https://repo.maven.apache.org/maven2/com/databricks/spark-avro_2.10/2.0.1/

导入到Spark项目里

文件：

https://github.com/databricks/spark-avro/raw/master/src/test/resources/episodes.avro

2.使用

代码：

/**
 * @author xubo
 * @time 20160502
 * ref https://github.com/databricks/spark-avro
 */
package org.apache.spark.avro.learning

import org.apache.spark.sql.SQLContext
import org.apache.spark.SparkConf
import org.apache.spark.SparkContext
import java.text.SimpleDateFormat
import java.util.Date

object learning1 {
  def main(args: Array[String]) {
    val conf = new SparkConf().setAppName("readFileFromFaFq").setMaster("local")
    val sc = new SparkContext(conf)
    // import needed for the .avro method to be added
    import com.databricks.spark.avro._

    val sqlContext = new SQLContext(sc)

    // The Avro records get converted to Spark types, filtered, and
    // then written back out as Avro records
    val df = sqlContext.read.avro("file/data/avro/input/episodes.avro")
    df.show
    val iString = new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date())

    df.filter("doctor > 5").write.avro("file/data/avro/output/episodes/avro" + iString)
    df.filter("doctor > 5").show
  }
}

源文件：

Obj
avro.schema?{"type":"record","name":"episodes","namespace":"testing.hive.avro.serde","fields":[{"name":"title","type":"string","doc":"episode title"},{"name":"air_date","type":"string","doc":"initial date"},{"name":"doctor","type":"int","doc":"main actor playing the Doctor in episode"}]} 巏RLS|]Z^{??"The Eleventh Hour3 April 2010"The Doctor's Wife14 May 2011&Horror of Fang Rock 3 September 1977$An Unearthly Child 23 November 1963*The Mysterious Planet 6 September 1986Rose26 March 2005.The Power of the Daleks5 November 1966Castrolava4 January 1982
巏RLS|]Z^{?

运行结果：

+--------------------+----------------+------+
|               title|        air_date|doctor|
+--------------------+----------------+------+
|   The Eleventh Hour|    3 April 2010|    11|
|   The Doctor's Wife|     14 May 2011|    11|
| Horror of Fang Rock|3 September 1977|     4|
|  An Unearthly Child|23 November 1963|     1|
|The Mysterious Pl...|6 September 1986|     6|
|                Rose|   26 March 2005|     9|
|The Power of the ...| 5 November 1966|     2|
|          Castrolava|  4 January 1982|     5|
+--------------------+----------------+------+

+--------------------+----------------+------+
|               title|        air_date|doctor|
+--------------------+----------------+------+
|   The Eleventh Hour|    3 April 2010|    11|
|   The Doctor's Wife|     14 May 2011|    11|
|The Mysterious Pl...|6 September 1986|     6|
|                Rose|   26 March 2005|     9|
+--------------------+----------------+------+

写入结果：

Obj
avro.codecsnappyavro.schema�{"type":"record","name":"topLevelRecord","fields":[{"name":"title","type":["string","null"]},{"name":"air_date","type":["string","null"]},{"name":"doctor","type":["int","null"]}]}

参考：

https://github.com/databricks/spark-avro