相关疑难解决方法(0)

在以下代码中,相同的模式在使用Java API时匹配,但在使用Scala模式匹配时不匹配.

import java.util.regex.Pattern

object Main extends App {
  val text = "/oAuth.html?state=abcde&code=hfjksdhfrufhjjfkdjfkds"

  val statePatternString = """\/.*\?.*state=([^&\?]*)"""
  val statePattern = statePatternString.r
  val statePatternJ = Pattern.compile(statePatternString)

  val sj = statePatternJ.matcher(text)
  val sjMatch = if (sj.find()) sj.group(1) else ""
  println(s"Java match $sjMatch")

  val ss = statePattern.unapplySeq(text)
  println(s"Scala unapplySeq $ss")
  val sm = statePattern.findFirstIn(text)
  println(s"Scala findFirstIn $sm")

  text match {
    case statePattern(s) =>
      println(s"Scala matching $s")
    case _ =>
      println("Scala not matching")
  }

}

应用输出是:

Java匹配abcde

Scala unapplySeq无

Scala findFirstIn Some(/oAuth.html?state=abcde)

Scala不匹配

什么导致Scala正则表达式unapplySeq失败？