NPE exception using wsgen ant task with xmlbeans binding

I use ant -verbose to print out the stacktrace about where the NPE occured:

Apache Ant version 1.6.5 compiled on June 2 2005
Buildfile: C:\Documents and Settings\wzhou\workspace\xfire\build.xml
parsing buildfile C:\Documents and Settings\wzhou\workspace\xfire\build.xml with URI = file:///C:/Documents%20and%20Sett
ings/wzhou/workspace/xfire/build.xml
Project base dir set to: C:\Documents and Settings\wzhou\workspace\xfire
Build sequence for target(s) `generate-ws-client' is [generate-ws-client]
Complete build sequence is [generate-ws-client, ]
generate-ws-client:
[wsgen] log4j:WARN No appenders could be found for logger (org.codehaus.xfire.transport.DefaultTransportManager).
[wsgen] log4j:WARN Please initialize the log4j system properly.

BUILD FAILED
C:\Documents and Settings\wzhou\workspace\xfire\build.xml:18: java.lang.NullPointerException
at org.codehaus.xfire.gen.WsGenTask.execute(WsGenTask.java:41)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
at org.apache.tools.ant.Task.perform(Task.java:364)
at org.apache.tools.ant.Target.execute(Target.java:341)
at org.apache.tools.ant.Target.performTasks(Target.java:369)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1216)
at org.apache.tools.ant.Project.executeTarget(Project.java:1185)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:40)
at org.eclipse.ant.internal.ui.antsupport.EclipseDefaultExecutor.executeTargets(EclipseDefaultExecutor.java:32)
at org.apache.tools.ant.Project.executeTargets(Project.java:1068)
at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:423)
at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:137)
Caused by: java.lang.NullPointerException
at org.apache.xmlbeans.impl.common.QNameHelper.hexsafedir(QNameHelper.java:176)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderImpl.typeSystemForComponent(SchemaTypeLoaderImpl.java:249)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderImpl.findDocumentTypeRef(SchemaTypeLoaderImpl.java:430)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.findDocumentType(SchemaTypeLoaderBase.java:129)
at org.codehaus.xfire.gen.xmlbeans.XmlBeansSchemaSupport.getType(XmlBeansSchemaSupport.java:50)
at org.codehaus.xfire.gen.xmlbeans.XmlBeansSchemaSupport.getType(XmlBeansSchemaSupport.java:24)
at org.codehaus.xfire.gen.jsr181.AbstractServiceGenerator.getReturnType(AbstractServiceGenerator.java:343)
at org.codehaus.xfire.gen.jsr181.AbstractServiceGenerator.generate(AbstractServiceGenerator.java:77)
at org.codehaus.xfire.gen.jsr181.ServiceInterfaceGenerator.generate(ServiceInterfaceGenerator.java:43)
at org.codehaus.xfire.gen.jsr181.AbstractServiceGenerator.generate(AbstractServiceGenerator.java:50)
at org.codehaus.xfire.gen.Wsdl11Generator.generate(Wsdl11Generator.java:73)
at org.codehaus.xfire.gen.WsGenTask.execute(WsGenTask.java:37)
... 11 more
— Nested Exception —
java.lang.NullPointerException
at org.apache.xmlbeans.impl.common.QNameHelper.hexsafedir(QNameHelper.java:176)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderImpl.typeSystemForComponent(SchemaTypeLoaderImpl.java:249)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderImpl.findDocumentTypeRef(SchemaTypeLoaderImpl.java:430)
at org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.findDocumentType(SchemaTypeLoaderBase.java:129)
at org.codehaus.xfire.gen.xmlbeans.XmlBeansSchemaSupport.getType(XmlBeansSchemaSupport.java:50)
at org.codehaus.xfire.gen.xmlbeans.XmlBeansSchemaSupport.getType(XmlBeansSchemaSupport.java:24)
at org.codehaus.xfire.gen.jsr181.AbstractServiceGenerator.getReturnType(AbstractServiceGenerator.java:343)
at org.codehaus.xfire.gen.jsr181.AbstractServiceGenerator.generate(AbstractServiceGenerator.java:77)
at org.codehaus.xfire.gen.jsr181.ServiceInterfaceGenerator.generate(ServiceInterfaceGenerator.java:43)
at org.codehaus.xfire.gen.jsr181.AbstractServiceGenerator.generate(AbstractServiceGenerator.java:50)
at org.codehaus.xfire.gen.Wsdl11Generator.generate(Wsdl11Generator.java:73)
at org.codehaus.xfire.gen.WsGenTask.execute(WsGenTask.java:37)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275)
at org.apache.tools.ant.Task.perform(Task.java:364)
at org.apache.tools.ant.Target.execute(Target.java:341)
at org.apache.tools.ant.Target.performTasks(Target.java:369)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1216)
at org.apache.tools.ant.Project.executeTarget(Project.java:1185)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:40)
at org.eclipse.ant.internal.ui.antsupport.EclipseDefaultExecutor.executeTargets(EclipseDefaultExecutor.java:32)
at org.apache.tools.ant.Project.executeTargets(Project.java:1068)
at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:423)
at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:137)

Total time: 3 seconds

Looks like a duplicate of : http://jira.codehaus.org/browse/XFIRE-332
Check the comments on the bottom of bug XFIRE-332.

Ahha, I got it. Thanks. The document needs to be updated. It is not obvious to have to generate xmlbean classes separately before running wsgen task.

duplicate issue with XFIRE-332.