scala code for regex pattern matching - regex

Question

I am new to scala. I am trying something on the regular expression pattern matching. I am following the example from here: https://alvinalexander.com/scala/how-to-extract-parts-strings-match-regular-expression-regex-scala
Given below is the code that I have written which works but is obviously not the best way.
Scenario: I have a regex pattern with me.
"([a-z0-9]+)_([0-9]+)_([v|V][0-9]+)_(\\d{4})(\\d{2})(\\d{2}).(xls|xlsx)".r
I have a string that defines what I am expecting for a given scenario. val param = "manufacturer/order/version"
Question: I don't want to pass hardcoded values in case pattern(manufacturer, order, version) but get the output in the variables manufacturer, order and version? One way is defining all the variables initially, but that would mean changing the code every time i need to change a string. Is there a way to do it dynamically or a better way of using regex in scala.
package com.testing
class DynamicFolder() {
def dynamicPath(fileName: String): Map[String, String] = {
println("File Name: " + fileName)
val param = "manufacturer/order/version"
var patternString = param.replaceAll("/", ", ")
println(patternString)
val pattern = "([a-z0-9]+)_([0-9]+)_([v|V][0-9]+)_(\\d{4})(\\d{2})(\\d{2}).(xls|xlsx)".r
val paramMap: Map[String, String] = fileName match {
case pattern(manufacturer, order, version) => {
println(s"Manufacturer: $manufacturer, Order: $order, version: $version")
Map("manufacturer" -> manufacturer, "order" -> order, "version" -> version)
}
case pattern(manufacturer, order, version, yyyy, mm, dd, format) => {
println(s"Manufacturer: $manufacturer, Order: $order, version: $version")
Map("manufacturer" -> manufacturer, "order" -> order, "version" -> version)
}
case _ => throw new IllegalArgumentException
}
paramMap
}
}
object hello {
def main(args: Array[String]): Unit = {
var dynamicFolder = new DynamicFolder
val fileName = "man1_18356_v1_20180202.xls"
val tgtParams = dynamicFolder.dynamicPath(fileName)
var tgtPath = ""
for ((k, v) <- tgtParams) {
printf("key: %s, value: %s\n", k, v)
tgtPath = tgtPath + "/" + tgtParams(k)
}
println ("Target path: "+tgtPath)
}
}
Output of the code:
File Name: man1_18356_v1_20180202.xls
manufacturer, version, order
Manufacturer: man1, Order: 18356, version: v1
key: manufacturer, value: man1
key: order, value: 18356
key: version, value: v1
Target path: /man1/18356/v1
Thanks!

Answer 1

This is how you can collect all groups and process them yourself:
val paramMap: Map[String, String] = fileName match {
case pattern(groups#_*) if groups.nonEmpty => {
// Access group with groups(0), groups(1) etc.
}
case _ => throw new IllegalArgumentException
}