我尝试迭代XML文件以获取特定类型<Card>
的所有元素。此类型还可以具有可选的属性。
XML示例:
<Lesson>
<Description>Description</Description>
<Card learnedTimestamp="1234567", isRepeatedByTyping="true", batch="5">
<FrontSide>Foo1</FrontSide>
<ReverseSide>Bar1</ReverseSide>
<InformationLine>Info1</InformationLine>
</Card>
<Card>
<FrontSide>Foo2</FrontSide>
<ReverseSide>Bar2</ReverseSide>
<InformationLine>Info2</InformationLine>
</Card>
</Lesson>
Scala代码:
class XMLParser(fqFileName: String) {
val pauDoc: Elem = XML.loadFile(fqFileName)
def printXMLFile() = {
var cardCount = 0
val lesson = (pauDoc \\ "Lesson")
for(val card <- lesson \\ "Card"){
cardCount = cardCount + 1
println("Card No " + cardCount)
val frontSide = (card \\ "FrontSide").text
println("FrontSide Value: " + frontSide)
val reverseSide = (card \\ "ReverseSide").text
println("ReverseSide Value.text: " + reverseSide)
val infoLine = (card \\ "InformationLine").text
println("InformationLine Value: " + infoLine)
}
}
}
但是,只有<Card>
元素没有任何属性时,此代码才有效。有没有人知道我如何处理属性,特别是如果它们是可选的?
P.S。:这是我得到的例外。
Exception in thread "main" org.xml.sax.SAXParseException: Element type "Card" must be followed by either attribute specifications, ">" or "/>".
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.seekCloseOfStartTag(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
at javax.xml.parsers.SAXParser.parse(Unknown Source)
at scala.xml.factory.XMLLoader$class.loadXML(XMLLoader.scala:40)
at scala.xml.XML$.loadXML(XML.scala:40)
at scala.xml.factory.XMLLoader$class.loadFile(XMLLoader.scala:49)
at scala.xml.XML$.loadFile(XML.scala:40)
at de.htwg_konstanz.ecardman.common.XMLParser.<init>(XMLParser.scala:7)
at de.htwg_konstanz.ecardman.common.XMLParserMain$.main(XMLParserMain.scala:23)
at de.htwg_konstanz.ecardman.common.XMLParserMain.main(XMLParserMain.scala)
答案 0 :(得分:2)
这适用于2.9.1:
val raw = """<Lesson>
<Description>Description</Description>
<Card learnedTimestamp="1234567" isRepeatedByTyping="true" batch="5">
<FrontSide>Foo1</FrontSide>
<ReverseSide>Bar1</ReverseSide>
<InformationLine>Info1</InformationLine>
</Card>
<Card>
<FrontSide>Foo2</FrontSide>
<ReverseSide>Bar2</ReverseSide>
<InformationLine>Info2</InformationLine>
</Card>
</Lesson>"""
class XMLParser(fqFileName: String) {
import xml._
val pauDoc: Elem = XML.loadString(fqFileName)
def printXMLFile() = {
var cardCount = 0
val lesson = (pauDoc \\ "Lesson")
for(card <- lesson \\ "Card"){
cardCount = cardCount + 1
println("Card No " + cardCount)
val frontSide = (card \\ "FrontSide").text
println("FrontSide Value: " + frontSide)
val reverseSide = (card \\ "ReverseSide").text
println("ReverseSide Value.text: " + reverseSide)
val infoLine = (card \\ "InformationLine").text
println("InformationLine Value: " + infoLine)
}
}
}
new XMLParser(raw).printXMLFile()
打印:
Card No 1
FrontSide Value: Foo1
ReverseSide Value.text: Bar1
InformationLine Value: Info1
Card No 2
FrontSide Value: Foo2
ReverseSide Value.text: Bar2
InformationLine Value: Info2
这不是你所期望的吗?我刚用loadString
代替loadFile
,但这只是用于测试。