Question

我正在关注Pascal Bugnion的书Scala for Data Science的代码。表示交易的第一类

case class Transaction(
id:Option[Int], // unique identifier
candidate:String, // candidate receiving the donation
contributor:String, // name of the contributor
contributorState:String, // contributor state
contributorOccupation:Option[String], // contributor job
amount:Long, // amount in cents
date:Date // date of the donation
)

defined class Transaction

然后我在FEData单例对象的帮助下加载了数据

scala> val ohioData = FECData.loadOhio
ohioData: FECData = FECData@7e83a375

FECData对象具有属性事务

scala> val ohioTransactions = ohioData.transactions
ohioTransactions: Iterator[Transaction] = non-empty iterator

当我尝试打印前5个交易时

scala> ohioTransactions.take(5).foreach(println)
java.text.ParseException: Unparseable date: "06-DEC-11"
  at java.text.DateFormat.parse(DateFormat.java:366)
  at FECData$$anonfun$1.apply(FECData.scala:26)
  at FECData$$anonfun$1.apply(FECData.scala:16)
  at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)

让我们来看看csv文件的前5行 candidate_id，候选，contributor_name，contributor_state，contributor_occupation，金额，日期

P80000748,"Paul, Ron","BROWN, TODD W MR.",OH,ENGINEER,50.0,06-DEC-11
P80000748,"Paul, Ron","DIEHL, MARGO SONJA",OH,RETIRED,25.0,06-DEC-11
P80000748,"Paul, Ron","KIRCHMEYER, BENJAMIN",OH,COMPUTER PROGRAMMER,201.2,06-DEC-11
P80003338,"Obama, Barack","KEYES, STEPHEN",OH,HR EXECUTIVE / ATTORNEY,100.0,30-SEP-11
P80003338,"Obama, Barack","MURPHY, MIKE W",OH,MANAGER,50.0,26-SEP-11

为什么？

Answer 1

好的，问题是在FECData中将dateParser定义为new SimpleDateFormat("DD-MMM-YY")。

根据https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html#SimpleDateFormat(java.lang.String)，它使用给定的模式构建SimpleDateFormat，默认区域设置的默认日期格式符号。

问题是您的（JVM的）默认语言环境不是Locale.ENGLISH，因此DEC的{{1}}部分未正确解析。

您只需要修补"06-DEC-11"：将FECData替换为private val dateParser = new SimpleDateFormat("DD-MMM-YY")。

参考。 private val dateParser = new SimpleDateFormat("DD-MMM-YY", java.util.Locale.ENGLISH) https://docs.oracle.com/javase/7/docs/api/java/util/Locale.html

java.text.ParseException：Unparseable date：＆＃34; 06-DEC-11＆＃34;

1 个答案: