从字符串中提取ADL FQDN的Regex

Question

我试图使用Scala中的Regex从给定的字符串中提取Datalake。有人能帮忙吗？

Input = adl://asbwje-fhs.azuredatalakestore.net/123/wds/xyz=456/

Output = adl://asbwje-fhs.azuredatalakestore.net

ADL可以在定义中包含[a-zA-Z_-]。我试过以下几种方法：

scala> val ADLStorePattern = "(.*) ([a-zA-Z_-]+) (.net) (.*)".r
ADLStorePattern: scala.util.matching.Regex = (.*) ([a-zA-Z_-]+) (.net) (.*)

scala> val ADLStorePattern(adl, _, _) = "adl://asbwje-fhs.azuredatalakestore.net"
scala.MatchError: adl://asbwje-fhs.azuredatalakestore.net (of class java.lang.String)
  ... 32 elided

scala> val ADLStorePattern(adl, _) = "adl://asbwje-fhs.azuredatalakestore.net"
scala.MatchError: adl://asbwje-fhs.azuredatalakestore.net (of class java.lang.String)
  ... 32 elided

scala> val ADLStorePattern(_, adl, _) = "adl://asbwje-fhs.azuredatalakestore.net"
scala.MatchError: adl://asbwje-fhs.azuredatalakestore.net (of class java.lang.String)
  ... 32 elided

scala> val ADLStorePattern(_, adl, _, _) = "adl://asbwje-fhs.azuredatalakestore.net"
scala.MatchError: adl://asbwje-fhs.azuredatalakestore.net (of class java.lang.String)
  ... 32 elided

scala> val ADLStorePattern = "([a-zA-Z_-]+) (.net) (.*)".r
ADLStorePattern: scala.util.matching.Regex = ([a-zA-Z_-]+) (.net) (.*)

scala> val ADLStorePattern(adl, _) = "adl://asbwje-fhs.azuredatalakestore.net"
scala.MatchError: adl://asbwje-fhs.azuredatalakestore.net (of class java.lang.String)
  ... 32 elided

scala> val ADLStorePattern(adl, _, _) = "adl://asbwje-fhs.azuredatalakestore.net"
scala.MatchError: adl://asbwje-fhs.azuredatalakestore.net (of class java.lang.String)
  ... 32 elided

Answer 1

您可以从Regex模式的第一组提取FQDN，如下所示：

val url = "adl://asbwje-fhs.azuredatalakestore.net/123/wds/xyz=456/"

val pattern = """(adl://[^/]*)(/.*)?""".r

val fqdn: String = url match {
  case pattern(x, _) => x
  case _ => "No match!"
}
// fqdn: String = adl://asbwje-fhs.azuredatalakestore.net

第二个可选组包括URL仅由FQDN部分组成的情况。