Spark: Reading files using different delimiter than new line
In Spark shell, I extracted data according to Setting textinputformat.record.delimiter in spark:
$ spark-shell
...
scala> import org.apache.hadoop.io.LongWritable
import org.apache.hadoop.io.LongWritable
scala> import org.apache.hadoop.io.Text
import org.apache.hadoop.io.Text
scala> import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.conf.Configuration
scala> import org.apache.hadoop.mapreduce.lib.input.TextInputFormat
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat
scala> val conf = new Configuration
conf: org.apache.hadoop.conf.Configuration = Configuration: core-default.xml, core-site.xml, mapred-default.xml, mapred-site.xml, yarn-default.xml, yarn-site.xml
scala> conf.set("textinputformat.record.delimiter", "\u0001")
scala> val data = sc.newAPIHadoopFile("mydata.txt", classOf[TextInputFormat], classOf[LongWritable], classOf[Text], conf).map(_._2.toString)
data: org.apache.spark.rdd.RDD[(org.apache.hadoop.io.LongWritable, org.apache.hadoop.io.Text)] = NewHadoopRDD[0] at newAPIHadoopFile at <console>:19
sc.newAPIHadoopFile("mydata.txt", ...)
is a RDD[(LongWritable, Text)]
, where the first part of the elements is the starting character index, and the second part is the actual text delimited by "\u0001"
.
You can use textinputformat.record.delimiter
to set the delimiter for TextInputFormat
, E.g.,
import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.mapreduce.Job
import org.apache.hadoop.io.{LongWritable, Text}
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat
val conf = new Configuration(sc.hadoopConfiguration)
conf.set("textinputformat.record.delimiter", "X")
val input = sc.newAPIHadoopFile("file_path", classOf[TextInputFormat], classOf[LongWritable], classOf[Text], conf)
val lines = input.map { case (_, text) => text.toString}
println(lines.collect)
For example, my input is a file containing one line aXbXcXd
. The above code will output
Array(a, b, c, d)