2
在执行以下代码：MalformedURLException的使用文件URI
doc = builder.parse(file);
其中doc是org.w3c.dom.Document和builder一个实例是javax.xml.parsers.DocumentBuilder一个实例，我发现了以下异常：
Exception in thread "main" java.net.MalformedURLException: unknown protocol: c
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.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.DOMParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
at com.acme.ItemToThetaValues.createFiles(ItemToThetaValues.java:47)
它在文件的这一行上窒息：
<!DOCTYPE questestinterop SYSTEM "C:\Program Files\Acme\parsers\acme_full.dtd">
我的机器上没有出现此错误，而用户正在使用他的机器。我们都使用Sun JRE的第6版。当他在路径中使用双反斜杠而不是单反斜杠时，以及使用正斜杠而不是反斜杠时，也会发生此错误。
首先，XML是否正确？路径表达是否正确？其次，为什么这个错误发生在一台电脑上，而不是另一台电脑上？