Scala - Looping through an array and applying regex - regex

Question

I have an array of log messages. An example of a message in the array below -
Example below -
Output(RequiredSystemOutput(2017-05-21 13:43:59,085 [scala-execution-context-global-43] ERROR Database - Error executing database store for URI (uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350) for transition to state FileArchived : Could not acquire connection-1 - Connection is not available, request timed out after 15000ms.,2020-01-21 13:43:59.086 GMT)) }}
So imagine the above but repeated.
I would like to loop through the array of individual log messages so that rather than printing out the whole message for each one, it only prints out the uri and offset, like so -
uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350
I have the regex which is val regex = "\\(([^()]+)\\)" but I am struggling to apply this in Scala, especially in an array.

Answer 1

I am not sure that the regex which you mentioned in your code will help because you have provided just one example. I can provide with a more selective for the given example.
val string = "Output(RequiredSystemOutput(2017-05-21 13:43:59,085 [scala-execution-context-global-43] ERROR Database - Error executing database store for URI (uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350) for transition to state FileArchived : Could not acquire connection-1 - Connection is not available, request timed out after 15000ms.,2020-01-21 13:43:59.086 GMT)) }}"
val regex = "\\((uri\\:[0-9a-zA-Z\\-]+,offset\\:[0-9]+)\\)".r
val matchOption = regex.findFirstMatchIn(string)
val extractedStringOption = matchOption.map(_.group(1))
// extractedStringOption: Option[String] = Some(uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350)

Answer 2

You could loop the array, and if there is only a single match use findFirstMatchIn.
The pattern you use is very broad, and you might make it a bit more specific by for example starting the match inside the capturing group with uri:
Regex demo | Scala demo
For example
val array = Array (
"Output(RequiredSystemOutput(2017-05-21 13:43:59,085 [scala-execution-context-global-43] ERROR Database - Error executing database store for URI (uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350) for transition to state FileArchived : Could not acquire connection-1 - Connection is not available, request timed out after 15000ms.,2020-01-21 13:43:59.086 GMT)) }}",
"Output(RequiredSystemOutput(2017-05-21 13:43:59,085 [scala-execution-context-global-43] ERROR Database - Error executing database store for URI (uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350) for transition to state FileArchived : Could not acquire connection-1 - Connection is not available, request timed out after 15000ms.,2020-01-21 13:43:59.086 GMT)) }}"
)
val pattern = """\((uri:[^()]+)\)""".r
val res: Array[String] = for {
s <- array
m <- pattern.findAllMatchIn(s)
} yield m.group(1)
res.foreach(println)
Output
uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350
uri:becbfx08-c491-44e3-bd01-d12c0305bcbf,offset:12054350
To get a more specific match, you could use a character class and repeat the preceding hyphen:
\((uri:[a-z0-9]+(?:-[a-z0-9]+)+,offset:[0-9]+)\)
Regex demo