使用Stax使用DTD解析XML時出錯

Question

我必須解析具有以下內容的有效xml文檔：

<?xml version='1.0' encoding="ISO-8859-1" standalone="no" ?>
<!DOCTYPE WMT_MS_Capabilities SYSTEM "http://schemas.opengis.net/wms/1.1.1/WMS_MS_Capabilities.dtd"
 [
<!ELEMENT VendorSpecificCapabilities (inspire_vs:ExtendedCapabilities)><!ELEMENT inspire_vs:ExtendedCapabilities ((inspire_common:MetadataUrl, inspire_common:SupportedLanguages, inspire_common:ResponseLanguage) | (inspire_common:ResourceLocator+, inspire_common:ResourceType, inspire_common:TemporalReference+, inspire_common:Conformity+, inspire_common:MetadataPointOfContact+, inspire_common:MetadataDate, inspire_common:SpatialDataServiceType, inspire_common:MandatoryKeyword+, inspire_common:Keyword*, inspire_common:SupportedLanguages, inspire_common:ResponseLanguage, inspire_common:MetadataUrl?))><!ATTLIST inspire_vs:ExtendedCapabilities xmlns:inspire_vs CDATA #FIXED "http://inspire.ec.europa.eu/schemas/inspire_vs/1.0" ><!ELEMENT inspire_common:MetadataUrl (inspire_common:URL, inspire_common:MediaType*)><!ATTLIST inspire_common:MetadataUrl xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" xmlns:xsi CDATA #FIXED "http://www.w3.org/2001/XMLSchema-instance" xsi:type CDATA #FIXED "inspire_common:resourceLocatorType" ><!ELEMENT inspire_common:URL (#PCDATA)><!ATTLIST inspire_common:URL xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:MediaType (#PCDATA)><!ATTLIST inspire_common:MediaType xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:SupportedLanguages (inspire_common:DefaultLanguage, inspire_common:SupportedLanguage*)><!ATTLIST inspire_common:SupportedLanguages xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:DefaultLanguage (inspire_common:Language)><!ATTLIST inspire_common:DefaultLanguage xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:SupportedLanguage (inspire_common:Language)><!ATTLIST inspire_common:SupportedLanguage xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:ResponseLanguage (inspire_common:Language)><!ATTLIST inspire_common:ResponseLanguage xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:Language (#PCDATA)><!ATTLIST inspire_common:Language xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:ResourceLocator (inspire_common:URL, inspire_common:MediaType*)><!ATTLIST inspire_common:ResourceLocator xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:ResourceType (#PCDATA)> <!ATTLIST inspire_common:ResourceType xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:TemporalReference (inspire_common:DateOfCreation?, inspire_common:DateOfLastRevision?, inspire_common:DateOfPublication*, inspire_common:TemporalExtent*)><!ATTLIST inspire_common:TemporalReference xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:DateOfCreation (#PCDATA)> <!ATTLIST inspire_common:DateOfCreation xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:DateOfLastRevision (#PCDATA)><!ATTLIST inspire_common:DateOfLastRevision xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:DateOfPublication (#PCDATA)><!ATTLIST inspire_common:DateOfPublication xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:TemporalExtent (inspire_common:IndividualDate | inspire_common:IntervalOfDates)><!ATTLIST inspire_common:TemporalExtent xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:IndividualDate (#PCDATA)> <!ATTLIST inspire_common:IndividualDate xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0"><!ELEMENT inspire_common:IntervalOfDates (inspire_common:StartingDate, inspire_common:EndDate)><!ATTLIST inspire_common:IntervalOfDates xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:StartingDate (#PCDATA)><!ATTLIST inspire_common:StartingDate xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:EndDate (#PCDATA)><!ATTLIST inspire_common:EndDate xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:Conformity (inspire_common:Specification, inspire_common:Degree)><!ATTLIST inspire_common:Conformity xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:Specification (inspire_common:Title, (inspire_common:DateOfPublication | inspire_common:DateOfCreation | inspire_common:DateOfLastRevision), inspire_common:URI*, inspire_common:ResourceLocator*)><!ATTLIST inspire_common:Specification xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:Title (#PCDATA)><!ATTLIST inspire_common:Title xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:URI (#PCDATA)><!ATTLIST inspire_common:URI xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:Degree (#PCDATA)><!ATTLIST inspire_common:Degree xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:MetadataPointOfContact (inspire_common:OrganisationName, inspire_common:EmailAddress)><!ATTLIST inspire_common:MetadataPointOfContact xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:OrganisationName (#PCDATA)><!ATTLIST inspire_common:OrganisationName  xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:EmailAddress (#PCDATA)><!ATTLIST inspire_common:EmailAddress xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:MetadataDate (#PCDATA)><!ATTLIST inspire_common:MetadataDate xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:SpatialDataServiceType (#PCDATA)><!ATTLIST inspire_common:SpatialDataServiceType xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:MandatoryKeyword (inspire_common:KeywordValue)><!ATTLIST inspire_common:MandatoryKeyword xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:KeywordValue (#PCDATA)><!ATTLIST inspire_common:KeywordValue xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" ><!ELEMENT inspire_common:Keyword (inspire_common:OriginatingControlledVocabulary?, inspire_common:KeywordValue)><!ATTLIST inspire_common:Keyword xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0" xmlns:xsi CDATA #FIXED "http://www.w3.org/2001/XMLSchemainstance" xsi:type (inspire_common:inspireTheme_bul | inspire_common:inspireTheme_cze | inspire_common:inspireTheme_dan | inspire_common:inspireTheme_dut | inspire_common:inspireTheme_eng | inspire_common:inspireTheme_est | inspire_common:inspireTheme_fin | inspire_common:inspireTheme_fre | inspire_common:inspireTheme_ger | inspire_common:inspireTheme_gre | inspire_common:inspireTheme_hun | inspire_common:inspireTheme_gle | inspire_common:inspireTheme_ita | inspire_common:inspireTheme_lav | inspire_common:inspireTheme_lit | inspire_common:inspireTheme_mlt | inspire_common:inspireTheme_pol | inspire_common:inspireTheme_por | inspire_common:inspireTheme_rum | inspire_common:inspireTheme_slo | inspire_common:inspireTheme_slv | inspire_common:inspireTheme_spa | inspire_common:inspireTheme_swe) #IMPLIED ><!ELEMENT inspire_common:OriginatingControlledVocabulary (inspire_common:Title, (inspire_common:DateOfPublication | inspire_common:DateOfCreation | inspire_common:DateOfLastRevision), inspire_common:URI*, inspire_common:ResourceLocator*)><!ATTLIST inspire_common:OriginatingControlledVocabulary xmlns:inspire_common CDATA #FIXED "http://inspire.ec.europa.eu/schemas/common/1.0">
 ]>  <!-- end of DOCTYPE declaration -->

<WMT_MS_Capabilities version="1.1.1">

<!-- more elements -->

<VendorSpecificCapabilities>
  <inspire_vs:ExtendedCapabilities>
  <!-- more elements -->
  </inspire_vs:ExtendedCapabilities>
</VendorSpecificCapabilities>
</WMT_MS_Capabilities>

我嘗試了以下StaX實現： com.sun.xml.internal.stream.XMLInputFactoryImpl和com.ctc.wstx.stax.WstxInputFactory （Woodstox）。

在兩種情況下，當Stax處理元素<inspire_vs:ExtendedCapabilities>時，都會出現異常：

使用Woodstox：

com.ctc.wstx.exc.WstxParsingException: Undeclared namespace prefix "inspire_vs"  at [row,col {unknown-source}]: [117,35]    at com.ctc.wstx.sr.StreamScanner.constructWfcException(StreamScanner.java:618) ~[woodstox-core-5.0.1.jar:5.0.1]     at com.ctc.wstx.sr.StreamScanner.throwParseError(StreamScanner.java:491) ~[woodstox-core-5.0.1.jar:5.0.1]   at com.ctc.wstx.sr.InputElementStack.resolveAndValidateElement(InputElementStack.java:503) ~[woodstox-core-5.0.1.jar:5.0.1]     at com.ctc.wstx.sr.BasicStreamReader.handleStartElem(BasicStreamReader.java:3052) ~[woodstox-core-5.0.1.jar:5.0.1]  at com.ctc.wstx.sr.BasicStreamReader.nextFromTree(BasicStreamReader.java:2912) ~[woodstox-core-5.0.1.jar:5.0.1]     at com.ctc.wstx.sr.BasicStreamReader.next(BasicStreamReader.java:1115) ~[woodstox-core-5.0.1.jar:5.0.1]     at org.codehaus.stax2.ri.Stax2EventReaderImpl.nextEvent(Stax2EventReaderImpl.java:255) ~[stax2-api-3.1.4.jar:?]

使用內部：

javax.xml.stream.XMLStreamException: ParseError at [row,col]:[117,36]
Message: http://www.w3.org/TR/1999/REC-xml-names-19990114#ElementPrefixUnbound?inspire_vs&inspire_vs:ExtendedCapabilities
    at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:601) ~[?:1.8.0_31]
    at com.sun.xml.internal.stream.XMLEventReaderImpl.nextEvent(XMLEventReaderImpl.java:83) ~[?:1.8.0_31]

我嘗試了這些屬性的幾種組合（對/錯），但沒有任何效果：

javax.xml.stream.isSupportingExternalEntities
javax.xml.stream.supportDTD
javax.xml.stream.isValidating

如何使用Stax解析此文檔？

Answer 1

您的問題不是文檔相對於DTD無效，而是文檔格式不正確，因為元素ExtendedCapabilities具有前綴inspire_vs ，但是沒有inspire_vs聲明任何名稱空間（即，通過名稱空間聲明xmlns:inspire_vs="...uri..." ）。

解決方法是，可以在Staxreader / XMLStreamReader中啟用名稱空間意識。 通過XMLInputFactory創建閱讀器時，需要設置：

XMLInputFactory factory = XMLInputFactory.newFactory();
factory.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, Boolean.FALSE);

XMLStreamReader reader = factory.createXMLStreamReader(...);