無法解析JavaHelp的toc.xml

Question

我爲JavaHelp的toc.xml文件編寫了一個XML解析器，以攔截我在tocitem標記中使用的一些屬性，這些屬性被JavaHelp忽略。這裏是toc.xml樣子：

<?xml version='1.0' encoding='ISO-8859-1' ?> 

<!DOCTYPE toc 
    PUBLIC "-//Sun Microsystems Inc.//DTD JavaHelp TOC Version 2.0//EN" 
    "http://java.sun.com/products/javahelp/toc_2_0.dtd"> 
<toc version="2.0"> 
    <tocitem text="Introduction" target="intro" action="myapp.help.introAction"/> 
</toc> 

我使用的是標準的SAX解析器解析toc.xml。當我解析文件，我得到以下異常：

myapp.help.TOCTreeFactory[WARN]: Failed to load TOC file from 'jar:file:/home/samad/myapp.jar!/workflow-help/toc.xml' 

Caused by: 
http://java.sun.com/javase/technologies/desktop/javahelp/toc_2_0.dtd 
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(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.XMLNSDocumentScannerImpl.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 myapp.help.TOCTreeFactory.createTree(TOCTreeFactory.java:43) 
... 

我打開URL http://java.sun.com/javase/technologies/desktop/javahelp/toc_2_0.dtd，我也得到一個404

我怎樣才能解決這個問題呢？我嘗試下載JavaHelp發行版，但它不包含SAX所需的toc_2_0.dtd文件。

Answer 1

您是否嘗試關閉工廠驗證？

SAXParserFactory pf = SAXParserFactory.newInstance(); 
pf.setValidating(false); 

另外一個替代... Stop your Java SAX parser from downloading DTDs

Answer 2

當以一個類似的問題的解決方案搜索，我第一次執導了這個問題。 setValidating()方法也不適用於我。 This answer到related question指向我SAXParserFactory的setFeature() method，它確實有效。

SAXParserFactory spf = SAXParserFactory.newInstance(); 
spf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);