java - 使用不带前缀 : NAMESPACE_ERR 的命名空间解析 XML

Question

我尝试解析两个 XML 文档:<root/>和 <root xmlns="hallo"/> .第一种情况工作正常，但后一种情况会引发异常(使用的 xalan/xerces 是 OpenJDK 1.6/1.7 附带的)。一些谷歌搜索表明发生这种情况是因为使用了没有前缀的 XML 命名空间。解析这样的文档对我来说感觉很正常而不是异国情调，所以我想知道如何解决这个问题。

我发现报告问题的所有其他人都在 SOAP 应用程序的上下文中遇到问题，并尝试做一些复杂的事情，但我找不到像我这样的简单设置的人。

有人建议将xalan升级到v2.7即可解决问题。我不知道 OpenJDK 附带了哪个版本，但我尝试将 v2.7.1 明确地放在类路径中，但没有任何改变。 (如何验证这是实际使用的版本？)。

有什么解决方法吗？

这是我的问题的测试:

public class DemoTest {

  @Test(dataProvider = "provide_xml")
  public void transform_doesNotThrowException(final String xml) throws Exception {
    final SAXParser saxParser = SAXParserFactory.newInstance().newSAXParser();
    final SAXSource saxSource = new SAXSource(saxParser.getXMLReader(), new InputSource(new StringReader(xml)));

    final Transformer transformer = TransformerFactory.newInstance().newTransformer();
    final Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
    final DOMResult result = new DOMResult(document);
    transformer.transform(saxSource, result);
  }

  @DataProvider
  public Object[][] provide_xml() {
    return new Object[][]{
        {"<root/>"}, // works
        {"<root xmlns=\"hello\"/>"} // broken
    };
  }
}

这是抛出的异常:

ERROR:  'NAMESPACE_ERR: An attempt is made to create or change an object in a way which is incorrect with regard to namespaces.'
javax.xml.transform.TransformerException: org.w3c.dom.DOMException: NAMESPACE_ERR: An attempt is made to create or change an object in a way which is incorrect with regard to namespaces.
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:720)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:317)
    at de.smotive.server.resource.ResourceManagerTest.testName(ResourceManagerTest.java:36)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at org.testng.internal.MethodHelper.invokeMethod(MethodHelper.java:641)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:677)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:850)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1154)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:137)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:121)
    at org.testng.TestRunner.runWorkers(TestRunner.java:1108)
    at org.testng.TestRunner.privateRun(TestRunner.java:737)
    at org.testng.TestRunner.run(TestRunner.java:596)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:315)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:310)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:272)
    at org.testng.SuiteRunner.run(SuiteRunner.java:221)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1027)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:964)
    at org.testng.TestNG.run(TestNG.java:896)
    at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:89)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:144)
    at org.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:111)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: org.w3c.dom.DOMException: NAMESPACE_ERR: An attempt is made to create or change an object in a way which is incorrect with regard to namespaces.
    at com.sun.org.apache.xerces.internal.dom.AttrNSImpl.setName(AttrNSImpl.java:108)
    at com.sun.org.apache.xerces.internal.dom.AttrNSImpl.<init>(AttrNSImpl.java:77)
    at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.createAttributeNS(CoreDocumentImpl.java:2142)
    at com.sun.org.apache.xerces.internal.dom.ElementImpl.setAttributeNS(ElementImpl.java:659)
    at com.sun.org.apache.xalan.internal.xsltc.trax.SAX2DOM.startElement(SAX2DOM.java:213)
    at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.closeStartTag(ToXMLSAXHandler.java:208)
    at com.sun.org.apache.xml.internal.serializer.ToSAXHandler.flushPending(ToSAXHandler.java:281)
    at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.endElement(ToXMLSAXHandler.java:247)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:604)
    at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:183)
    at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.emptyElement(XMLDTDValidator.java:814)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1320)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$ContentDriver.scanRootElementHook(XMLDocumentScannerImpl.java:1293)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3080)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:899)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:625)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:819)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:748)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1208)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:525)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transformIdentity(TransformerImpl.java:640)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:711)
    ... 32 more
---------
org.w3c.dom.DOMException: NAMESPACE_ERR: An attempt is made to create or change an object in a way which is incorrect with regard to namespaces.
    at com.sun.org.apache.xerces.internal.dom.AttrNSImpl.setName(AttrNSImpl.java:108)
    at com.sun.org.apache.xerces.internal.dom.AttrNSImpl.<init>(AttrNSImpl.java:77)
    at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.createAttributeNS(CoreDocumentImpl.java:2142)
    at com.sun.org.apache.xerces.internal.dom.ElementImpl.setAttributeNS(ElementImpl.java:659)
    at com.sun.org.apache.xalan.internal.xsltc.trax.SAX2DOM.startElement(SAX2DOM.java:213)
    at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.closeStartTag(ToXMLSAXHandler.java:208)
    at com.sun.org.apache.xml.internal.serializer.ToSAXHandler.flushPending(ToSAXHandler.java:281)
    at com.sun.org.apache.xml.internal.serializer.ToXMLSAXHandler.endElement(ToXMLSAXHandler.java:247)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:604)
    at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:183)
    at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.emptyElement(XMLDTDValidator.java:814)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1320)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$ContentDriver.scanRootElementHook(XMLDocumentScannerImpl.java:1293)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3080)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:899)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:625)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:488)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:819)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:748)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:123)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1208)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:525)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transformIdentity(TransformerImpl.java:640)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:711)
    at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(TransformerImpl.java:317)
    at de.smotive.server.resource.ResourceManagerTest.testName(ResourceManagerTest.java:36)

Answer 1

您正在尝试使用不支持命名空间的解析器来解析命名空间文档。

默认情况下，SAX 和 DOM 解析器不支持 namespace ，您需要显式调用 setNamespaceAware()工厂上。将您的代码更改为如下所示，您应该可以开始了:

SAXParserFactory spf = SAXParserFactory.newInstance();
spf.setNamespaceAware(true);
final SAXParser saxParser = spf.newSAXParser();