example.scala

val zip = new ZipStreamHelper(new ZipInputStream(...))

zip.rewindTo("hello.xml") { in =>
  val parser = STaxParser()
  val root   = parser.fromInputStream(in)
}

gistfile1.scala

import java.util.zip.{ZipEntry, ZipInputStream}
import java.io.InputStream


class ZipStreamHelper(zin: ZipInputStream) {
  def rewindTo(name: String)(handler: InputStream => Unit) {
    def findEntry(): Option[ZipEntry] = {
      val entry = zin.getNextEntry

      if (entry == null)
        None
      else if (entry.getName == name)
        Some(entry)
      else
        findEntry()
    }

    findEntry() match {
      case Some(_) => handler(zin)
      case None    =>
    }
  }
}