我正在尝试创建一个pig udf，它使用通过sista scala api接口的stanford corenlp包提取tweet中提到的位置。使用“sbt run”在本地运行时工作正常，但从pig调用时抛出“java.lang.nosuchmethoderror”异常：
从tagger edu/stanford/nlp/models/pos-tagger/english-left3words/english-left3words-distsim加载默认属性。从edu/stanford/nlp/models/pos-tagger/english-left3words/english-left3words-distsim读取pos-tagger模型从edu/stanford/nlp/models/ner/english.all.3class.distsim.crf.ser.gz 2013-06-1410:47:54952[通信线程]info org.apache.hadoop.mapred.localjobrunner-reduce>reduce done[7.5秒]。正在从edu/stanford/nlp/models/ner/english.muc.7class.distsim.crf.ser.gz加载分类器。。。2013-06-14 10:48:02108[低内存检测器]info org.apache.pig.impl.util.spillablemorymanager-第一个内存处理程序调用-收集阈值init=18546688（18112k）used=358671232（350264k）committed=366542848（357952k）max=699072512（682688k）done[5.0秒]。正在从edu/stanford/nlp/models/ner/english.conll.4class.distsim.crf.ser.gz加载分类器。。。2013-06-14 10:48:10522[低内存检测器]info org.apache.pig.impl.util.spillablemorymanager-第一个内存处理程序调用-使用阈值init=18546688（18112k）used=590012928（576184k）committed=597786624（583776k）max=699072512（682688k）done[5.6秒]。2013-06-14 10:48:11469[thread-11]警告org.apache.hadoop.mapred.localjobrunner-job\u local\u 0001 java.lang.nosuchmethoderror:org.joda.time.duration.compareto（lorg/joda/time/readableduration；）我在edu.stanford.nlp.time.sutime$duration.compareto（sutime。java:3406)在edu.stanford.nlp.time.sutime$duration.max（sutime。java:3488)在edu.stanford.nlp.time.sutime$时间差（sutime。java:1308)在edu.stanford.nlp.time.sutime$range.（sutime。java:3793)在斯坦福大学的时候。java:570)
以下是相关代码：

object CountryTokenizer {
  def tokenize(text: String): String = {
    val locations = TweetEntityExtractor.NERLocationFilter(text)
    println(locations)
    locations.map(x => Cities.country(x)).flatten.mkString(" ")
  }
}
class PigCountryTokenizer extends EvalFunc[String] {
  override def exec(tuple: Tuple): java.lang.String = {
    val text: java.lang.String = Util.cast[java.lang.String](tuple.get(0))
    CountryTokenizer.tokenize(text)
  }
}
object TweetEntityExtractor {
    val processor:Processor = new CoreNLPProcessor()
    def NERLocationFilter(text: String): List[String] =  {
        val doc = processor.mkDocument(text)
        processor.tagPartsOfSpeech(doc)
        processor.lemmatize(doc)
        processor.recognizeNamedEntities(doc)
        val locations = doc.sentences.map(sentence => {
            val entities = sentence.entities.map(List.fromArray(_)) match {
                case Some(l) => l
                case _ => List()
            }
            val words = List.fromArray(sentence.words)
            (words zip entities).filter(x => {
                x._1 != "" && x._2 == "LOCATION" 
            }).map(_._1)
        })
        List.fromArray(locations).flatten
    }
}

我正在使用sbt assembly构建一个fat jar，因此joda time jar文件应该是可以访问的。怎么回事？