问题
I'm struggling with this, and any information would be greatly appreciated. I have a project that has been using JAXB for some time to construct a Java Model from an XML Schema and uses that model. This has been working in Java 8 for some tie now.
However, I've upgraded to Open JDK 10 and I get this error when I attempt to Unmarshall an XML file into the Java objects....
java.lang.IllegalArgumentException: javax.xml.bind.UnmarshalException: unexpected element (uri:"http://www.minestar.cat.com/namespace/units",
local:"units"). Expected elements are <{}units>
at minestar.units.schema.parser.UnitsXmlParser.readXml(UnitsXmlParser.java:31)
at minestar.units.javagenerator.JavaGeneratorPlugin.execute(JavaGeneratorPlugin.java:41)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:290)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:194)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: javax.xml.bind.UnmarshalException: unexpected element (uri:"http://www.minestar.cat.com/namespace/units", local:"units"). Expected
elements are <{}units>
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.handleEvent(UnmarshallingContext.java:741)
at com.sun.xml.bind.v2.runtime.unmarshaller.Loader.reportError(Loader.java:262)
at com.sun.xml.bind.v2.runtime.unmarshaller.Loader.reportError(Loader.java:257)
at com.sun.xml.bind.v2.runtime.unmarshaller.Loader.reportUnexpectedChildElement(Loader.java:124)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext$DefaultRootLoader.childElement(UnmarshallingContext.java:1149)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext._startElement(UnmarshallingContext.java:574)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.startElement(UnmarshallingContext.java:556)
at com.sun.xml.bind.v2.runtime.unmarshaller.SAXConnector.startElement(SAXConnector.java:168)
at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:509)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:374)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(XMLNSDocumentScanner
Impl.java:613)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScan
nerImpl.java:3058)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:821)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:5
32)
at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:888)
at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:824)
at java.xml/com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at java.xml/com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:635)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:258)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:229)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:170)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:209)
at minestar.units.schema.parser.UnitsXmlParser.readXml(UnitsXmlParser.java:29)
... 23 more
I am using the maven-jaxb2-plugin to generate the sources, and they look fine. I have upgraded to the latest version of this plugin (at the time of this writing, 0.14.0). The classes are generated fine, and there is a package-info.java class generated and compiled into the resulting jar. The class in question looks like this at the top
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"dimensions",
"quantityTypes"
})
@XmlRootElement(name = "units")
public class Units {
@XmlElement(name = "dimension")
protected List<Dimension> dimensions;
@XmlElement(name = "quantityType")
protected List<QuantityType> quantityTypes;
And the package-info.java looks like this
@javax.xml.bind.annotation.XmlSchema(namespace = "http://www.minestar.cat.com/namespace/units", elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED)
package minestar.units.schema;
Because this is Java 10, I have added direct dependency entries to javax.xml.bind:jaxb-api:2.3.0, com.sun.xml.bind:jaxb-core:2.3.0 and com.sun.xml.bind:jaxb-impl:2.3.0.
I have tried changing JAXB implementation from the RI to Eclipse MOXy, but that made no difference.
As a test, I edited the generated Units.java class file above, adding the namespace attribute to the @XmlRootElement annotation...
@XmlRootElement(namespace = "http://www.minestar.cat.com/namespace/units", name = "units")
public class Units {
When this java file is compiled and used downstream, the XML file can be parsed. I do not receive the UnmarshalException. However, this source file is generated so I cannot rely on these changes staying put. Additionally, from everything that I have read from much more-informed people than myself, the package-info.class file (which is in the JAR file) should make the namespace value in the annotation unnecessary.
If there is something I have not set up correctly, I would be grateful for any assistance in getting this working in Java 10.
Thanks for any help, Ed
回答1:
I'm actually currently facing the same problem on Java 9.
Adding com.sun.xml.bind.backupWithParentNamespace system property makes it work, but I feel this is working around the problem.
I looked at the Java 9 source(have not looked at the Java 10 source yet), and it's inside the java.lang.Package.getPackageInfo() method that it tries to load the package-info class using:
...
String cn = packageName() + ".package-info";
Module module = module();
...
c = loader.loadClass(module, cn);
...
If I substitute it with
...
c = loader.loadClass(cn);
...
it manages to load it fine and all is well.
To me it looks like a JDK bug.
The latest maven-jaxb2-plugin does have the following option to turn off package-level annotations:
<packageLevelAnnotations>false</packageLevelAnnotations>
This resolved my problem.
Other XJC plugins seems to use "-npa" argument to turn off package-level annotations
回答2:
I have found the following solution for the same issue in my project with JDK 9:
JAXBContext ctx = JAXBContext.newInstance(YOUR_CLASS.class);
Unmarshaller unmarshaller = ctx.createUnmarshaller();
SAXParserFactory sax = SAXParserFactory.newInstance();
sax.setNamespaceAware(false); // This line is important!
XMLReader reader = sax.newSAXParser().getXMLReader();
Source source = new SAXSource(reader, new InputSource(new StringReader(xml)));
return (YOUR_CLASS) unmarshaller.unmarshal(source);
回答3:
I have a similar problem with namespaces, unmarshalling with JAXB in a home-made plugin.
I am using Java 11.
I resolved my problem upgrading maven to 3.6.2 (the problem occured with maven 3.5.2). Not sure to be able to explain why it works, but if it helps someone...
来源：https://stackoverflow.com/questions/52157040/jaxb-package-info-ignored-when-using-java-10