Try..Success..Failure Examples

Scala : Try, Success, Failure Examples

// Try..Success..Failure Examples

scala> import scala.util.{Try,Success,Failure}

import scala.util.{Try, Success, Failure}

scala> import scala.io.Source

import scala.io.Source

scala>  def deadline

7(path:String) : Try[List[String]] = {
     |  Try(Source.fromFile(path).getLines.toList)

     |  }

readFile: (path: String)scala.util.Try[List[String]]

scala> val  validFilePath = "E:\\DataSets\\guns.csv"

invalidFilePath: String = E:\DataSets\gunsnotfound.csv

scala> readFile(validFilePath)

res0: scala.util.Try[List[String]] = Success(List("","year","month","intent","police","sex","age","race","hispanic","place","education", "1",2012,"01"
,"Suicide",0,"M",34,"Asian/Pacific Islander",100,"Home",4, "2",2012,"01","Suicide",0,"F",21,"White",100,"Street",3, "3",2012,"01","Suicide",0,"M",60,"
White",100,"Other specified",4, "4",2012,"02","Suicide",0,"M",64,"White",100,"Home",4, "5",2012,"02","Suicide",0,"M",31,"White",100,"Other specified",
2, "6",2012,"02","Suicide",0,"M",17,"Native American/Native Alaskan",100,"Home",1, "7",2012,"02","Undetermined",0,"M",48,"White",100,"Home",2, "8",201
2,"03","Suicide",0,"M",41,"Native American/Native Alaskan",100,"Home",2, "9",2012,"02","Accidental",0,"M",50,"White",100,"Other specified",3, "10",201
2,"02","Suicide",0,"M",NA,"Black",998,"Home",5,...
scala>

scala> val invalidFilePath = "E:\\DataSets\\gunsnotfound.csv"

invalidFilePath: String = E:\DataSets\gunsnotfound.csv

scala> readFile(invalidFilePath)

res1: scala.util.Try[List[String]] = Failure(java.io.FileNotFoundException: E:\DataSets\gunsnotfound.csv (The system cannot find the file specified))


scala>  readFile(filePath) match {
     | case Success(a) => a.foreach(println)
     | case Failure(b) => println(b.getMessage)

     | }

{"athelete":"Michael Phelps","age":19,"country":"United States","year":"2004","closing":"08-29-04","sport":"Swimming","gold":6,"silver":0,"bronze":2,"
total":8}
{"athelete":"Michael Phelps","age":23,"country":"United States","year":"2008","closing":"08-24-08","sport":"Swimming","gold":8,"silver":0,"bronze":0,"
total":8}

 scala> def parseInt(a:String) : Try[Int] = Try(a.toInt)

parseInt: (a: String)scala.util.Try[Int]

scala> parseInt("2")

res5: scala.util.Try[Int] = Success(2)

scala> parseInt("I Love India")

res6: scala.util.Try[Int] = Failure(java.lang.NumberFormatException: For input string: "I Love India")


scala>  parseInt("2") match {
     |  case Success(a) => println(a)
     |  case Failure(b) => println(b.getMessage)

     |  }

2

scala> parseInt("333").toOption

res10: Option[Int] = Some(333)

scala> parseInt("IloveIndia").toOption

res11: Option[Int] = None