Scala exception handling using try and recover or toOption

Question

This is one handler written to recover from exception handling but when i call it doesn't recover but fails for below error message

def exphandler(i: Any): Try[Any] = Try(i) recover {
  case e => "Hello"
}


exphandler(BigDecimal(Cols(5))/adjust_currency_map(static(4))), //Open price


======================================
java.lang.NumberFormatException
                                              //|   at java.math.BigDecimal.<init>      (BigDecimal.java:459)
                                              //|   at java.math.BigDecimal.<init>(BigDecimal.java:728)
                                              //|   at scala.math.BigDecimal$.exact(BigDecimal.scala:125)
                                              //|   at scala.math.BigDecimal$.apply(BigDecimal.scala:283)
                                              //|   at com.DC.FTDataParser.FileParser$$anonfun$1.apply(FileParser.scala:115)

===============================

Any points will be helpful as it is making me mad.

score 3 · Answer 1 · edited May 23 '17 at 10:25

3

The argument to exphandler is being evaluated before the exception it throws can be caught by Try. You can fix this by using a by-name parameter:

def exphandler(i: => Any): Try[Any] = Try(i) recover {
  case e => "Hello"
}

Now the argument to exphandler won't be evaluated until inside of the call to Try, where the exception will be caught and represented as you're expecting.

edited May 23 '17 at 10:25

Community

1
1

answered Jun 22 '14 at 01:16

Travis Brown

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Thanks Travis. It worked but the result is showing as Success(14.565) not 14.565 as i expected. – user3341078 Jun 22 '14 at 01:33
Thanks Travis for the pointer. It worked now. def exphandler(i: => Any) = Try(i) match { case Success(v) => v case Failure(_) => "Hello" } – user3341078 Jun 22 '14 at 01:42
@user3341078 You can also do: `Try(i).getOrElse("hello")`. – Kigyo Jun 22 '14 at 23:05
Thanks Kigyo. I also tried that but it wasn't the problem. Call by value was the issue as pointed out by Travis. – user3341078 Jun 23 '14 at 20:38

Scala exception handling using try and recover or toOption

1 Answers1