RDD filter in scala spark

Question

I have a dataset and i want to extract those (review/text) which have (review/time) between x and y, for example ( 1183334400 < time < 1185926400),

here are part of my data:

product/productId: B000278ADA
product/title: Jobst Ultrasheer 15-20 Knee-High Silky Beige Large
product/price: 46.34
review/userId: A17KXW1PCUAIIN
review/profileName: Mark Anthony "Mark"
review/helpfulness: 4/4
review/score: 5.0
review/time: 1174435200
review/summary: Jobst UltraSheer Knee High Stockings
review/text: Does a very good job of relieving fatigue.

product/productId: B000278ADB
product/title: Jobst Ultrasheer 15-20 Knee-High Silky Beige Large
product/price: 46.34
review/userId: A9Q3932GX4FX8
review/profileName: Trina Wehle
review/helpfulness: 1/1
review/score: 3.0
review/time: 1352505600
review/summary: Delivery was very long wait.....
review/text: It took almost 3 weeks to recieve the two pairs of stockings .

product/productId: B000278ADB
product/title: Jobst Ultrasheer 15-20 Knee-High Silky Beige Large
product/price: 46.34
review/userId: AUIZ1GNBTG5OB
review/profileName: dgodoy
review/helpfulness: 1/1
review/score: 2.0
review/time: 1287014400
review/summary: sizes recomended in the size chart are not real
review/text: sizes are much smaller than what is recomended in the chart. I tried to put it and sheer it!.

my Spark-Scala Code :

import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.io.{LongWritable, Text}
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat
import org.apache.spark.{SparkConf, SparkContext}

object test1 {
  def main(args: Array[String]): Unit = {
    val conf1 = new SparkConf().setAppName("golabi1").setMaster("local")
    val sc = new SparkContext(conf1)
    val conf: Configuration = new Configuration
    conf.set("textinputformat.record.delimiter", "product/title:")
    val input1=sc.newAPIHadoopFile("data/Electronics.txt",     classOf[TextInputFormat], classOf[LongWritable], classOf[Text], conf)
    val lines = input1.map { text => text._2}
    val filt = lines.filter(text=>(text.toString.contains(tt => tt in (startdate until enddate))))
    filt.saveAsTextFile("data/filter1")
  }
}

but my code does not work well,

how can i filter these lines?

Answer 1

Is is much simpler than that. Try this:

object test1 
{
  def main(args: Array[String]): Unit = 
  {
    val conf1 = new SparkConf().setAppName("golabi1").setMaster("local")
    val sc = new SparkContext(conf1)

    def extractDateAndCompare(line: String): Boolean=
    {
        val from = line.indexOf("/time: ") + 7
        val to = line.indexOf("review/text: ") -1
        val date = line.substring(from, to).toLong
        date > startDate && date < endDate
    }

    sc.textFile("data/Electronics.txt")
        .filter(extractDateAndCompare)
        .saveAsTextFile("data/filter1")
  }
}

I usually find those intermediate auxiliary methods to make things much clearer. Of course, this assumes the boundary dates are defined somewhere and that the input file contain format issues. I did this intentionally to keep this simple, but adding a try, returning an Option clause and using flatMap() can help you avoid errors if you have them.

Also, your raw text is a little cumbersome, you might want to explore Json, TSV files or some other alternative, easier format.