Scalaのパーザコンビネータでアクセスログをパースしてみる ref: http://qiita.com/shrkw/items/e40f04a74840608fe62d

file0.txt

package com.example.service

import scala.io.Source
import scala.util.parsing.combinator.RegexParsers

object CloudFlareLogParserService {

  def resolve: Unit = {
    val accessLog =
      """
        |www.cloudflare.com 1.1.1.1 1383426540 "GET / HTTP/1.1" 200 11022 "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0)" "CLEAN.HUMAN 1383426470.808 off" "http://blog.cloudflare.com/"
        |www.cloudflare.com 1.1.1.1 1383426540 "GET / HTTP/1.1" 200 11022 "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0)" "CLEAN.HUMAN 1383426470.808 off" "http://blog.cloudflare.com/"
      """.stripMargin

    accessLog.split('\n').foreach {
      case line if line.trim.length != 0 => {
        try {
          println(CloudFlareLogParser.parseLine(line))
        } catch {
          case e: IllegalArgumentException => println(e)
        }
      }
      case _ =>
    }
  }

  case class CloudFlareAccessLog(host: String, ipAddress: String, size: Int, referrer: String)

  object CloudFlareLogParser extends RegexParsers {
    def lines = repsep(line, nl)

    def line = host ~ ipAddress ~ p2 ~ p3 ^^ { case host ~ ipAddress ~ size ~ referrer => CloudFlareAccessLog(host, ipAddress, size.toInt, referrer)}

    def nl = opt('\r') <~ '\n'

    def p2 = logWindow ~> request ~> statusCode ~> size

    def p3 = userAgent ~> cloudFlareInfo ~> referrer

    def host = """[\w.]+""".r

    def ipAddress = """[\d.]+""".r

    def logWindow = """\d+""".r

    def request = "\"" ~> "[^\"]*".r <~ "\""

    def statusCode = """\d{3}""".r

    def size = """\d+""".r

    def userAgent = "\"" ~> "[^\"]*".r <~ "\""

    def cloudFlareInfo = "\"" ~> "[\\w. ]*".r <~ "\""

    def referrer = "\"" ~> "[^\"]*".r <~ "\""

    def parseLines(input: String): List[CloudFlareAccessLog] = parseAll(lines, input).getOrElse {
      throw new IllegalArgumentException("Failed to parse: " + input)
    }

    def parseLine(input: String): CloudFlareAccessLog = parseLines(input).head
  }

}