NullPointerException in com.sun.tools.jxc.SchemaGenTask

Question

Given this ant script:

<?xml version="1.0" encoding="UTF-8"?> <project name="projectname" default="generate-schema" basedir="."> <taskdef name="schemagen" classname="com.sun.tools.jxc.SchemaGenTask"> <classpath> <fileset dir="../BuildJars/lib" includes="*.jar" /> </classpath> </taskdef> <target name="generate-schema"> <schemagen srcdir="src/gb/informaticasystems/messages" destdir="schema"> <schema namespace="http://www.informatica-systems.co.uk/aquarius/messages/1.0" file="messages-1.0.xsd" /> </schemagen> </target> </project> 

I get this error:

 Buildfile: C:\Users\davidcollie\workspace\aquarius-feature\AquariusServerLibrary\schemagen.xml generate-schema: [schemagen] Generating schema from 4 source files [schemagen] Problem encountered during annotation processing; [schemagen] see stacktrace below for more information. [schemagen] java.lang.NullPointerException [schemagen] at com.sun.tools.jxc.model.nav.APTNavigator$2.onDeclaredType(APTNavigator.java:428) [schemagen] at com.sun.tools.jxc.model.nav.APTNavigator$2.onClassType(APTNavigator.java:402) [schemagen] at com.sun.tools.jxc.model.nav.APTNavigator$2.onClassType(APTNavigator.java:456) [schemagen] at com.sun.istack.tools.APTTypeVisitor.apply(APTTypeVisitor.java:27) [schemagen] at com.sun.tools.jxc.model.nav.APTNavigator.getBaseClass(APTNavigator.java:109) [schemagen] at com.sun.tools.jxc.model.nav.APTNavigator.getBaseClass(APTNavigator.java:85) [schemagen] at com.sun.xml.bind.v2.model.impl.PropertyInfoImpl.getIndividualType(PropertyInfoImpl.java:190) [schemagen] at com.sun.xml.bind.v2.model.impl.PropertyInfoImpl.<init>(PropertyInfoImpl.java:132) [schemagen] at com.sun.xml.bind.v2.model.impl.MapPropertyInfoImpl.<init>(MapPropertyInfoImpl.java:67) [schemagen] at com.sun.xml.bind.v2.model.impl.ClassInfoImpl.createMapProperty(ClassInfoImpl.java:917) [schemagen] at com.sun.xml.bind.v2.model.impl.ClassInfoImpl.addProperty(ClassInfoImpl.java:874) [schemagen] at com.sun.xml.bind.v2.model.impl.ClassInfoImpl.findGetterSetterProperties(ClassInfoImpl.java:993) [schemagen] at com.sun.xml.bind.v2.model.impl.ClassInfoImpl.getProperties(ClassInfoImpl.java:303) [schemagen] at com.sun.xml.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:243) [schemagen] at com.sun.xml.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:209) [schemagen] at com.sun.xml.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:315) [schemagen] at com.sun.xml.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:330) [schemagen] at com.sun.tools.xjc.api.impl.j2s.JavaCompilerImpl.bind(JavaCompilerImpl.java:90) [schemagen] at com.sun.tools.jxc.apt.SchemaGenerator$1.process(SchemaGenerator.java:115) [schemagen] at com.sun.mirror.apt.AnnotationProcessors$CompositeAnnotationProcessor.process(AnnotationProcessors.java:60) [schemagen] at com.sun.tools.apt.comp.Apt.main(Apt.java:454) [schemagen] at com.sun.tools.apt.main.JavaCompiler.compile(JavaCompiler.java:258) [schemagen] at com.sun.tools.apt.main.Main.compile(Main.java:1102) [schemagen] at com.sun.tools.apt.main.Main.compile(Main.java:964) [schemagen] at com.sun.tools.apt.Main.processing(Main.java:95) [schemagen] at com.sun.tools.apt.Main.process(Main.java:85) [schemagen] at com.sun.tools.apt.Main.process(Main.java:67) [schemagen] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [schemagen] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [schemagen] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [schemagen] at java.lang.reflect.Method.invoke(Method.java:597) [schemagen] at com.sun.tools.jxc.AptBasedTask$InternalAptAdapter.execute(AptBasedTask.java:97) [schemagen] at com.sun.tools.jxc.AptBasedTask.compile(AptBasedTask.java:144) [schemagen] at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:820) [schemagen] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288) [schemagen] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [schemagen] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [schemagen] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [schemagen] at java.lang.reflect.Method.invoke(Method.java:597) [schemagen] at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105) [schemagen] at org.apache.tools.ant.Task.perform(Task.java:348) [schemagen] at org.apache.tools.ant.Target.execute(Target.java:357) [schemagen] at org.apache.tools.ant.Target.performTasks(Target.java:385) [schemagen] at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1329) [schemagen] at org.apache.tools.ant.Project.executeTarget(Project.java:1298) [schemagen] at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) [schemagen] at org.eclipse.ant.internal.ui.antsupport.EclipseDefaultExecutor.executeTargets(EclipseDefaultExecutor.java:32) [schemagen] at org.apache.tools.ant.Project.executeTargets(Project.java:1181) [schemagen] at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:423) [schemagen] at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:137) BUILD FAILED C:\Users\davidcollie\workspace\aquarius-feature\AquariusServerLibrary\schemagen.xml:11: schema generation failed Total time: 1 second 

Any ideas?

Answer 1

I had this problem because my srcdir was installed in the package folder that contained java files.

Changing this in the top-level source folder was better, but then the schematic wanted to make a scheme for all .java files in my source path (only 20% were actually jaxb classes).

My last call to ant is as follows:

 <property name="event.package" value="my/organisation/events"/> <schemagen srcdir="${src.main.java.dir}" destdir="META-INF/event-schema" classpathref="build.classpath"> <include name="${event.package}/Event1.java"/> <include name="${event.package}/Event2.java"/> </schemagen> 

Answer 2

The <schemagen> task should include a class path, probably equivalent to that in the <javac> task, which no doubt lives somewhere else in your Ant script. I also ask a question about the value of the srcdir attribute. It should point to the top of the source tree, and not inside any packages. It seems to me that "gb.informaticasystems.messages" may be a package in your project. If so, you should change the attribute to srcdir="src" . Thus, it should look something like this (you need to specify the class path):

 <target name="generate-schema"> <schemagen srcdir="src" destdir="schema"> <schema namespace="http://www.informatica-systems.co.uk/aquarius/messages/1.0" file="messages-1.0.xsd" /> <classpath> <!-- Classpath definition goes here --> </classpath> </schemagen> </target> 

Answer 3

I switched from running an ant script from 1.6 to 1.5, which then caused the correct stack traces, and from there I fixed the problem.

Answer 4

The reason for this error is very likely that some classes are missing that are used in the classes from which you want to create a schema. In my case, I had to include some missing classes that were not in my first set of matched wildcards. I used Maven and I had to switch from jaxb2-maven-plugin version 1.6 to 1.5, which shows some errors when verbose is set to true. Later I switched to the latest version.

  <execution> <phase>generate-resources</phase> <id>rest-webservice-schemagen</id> <goals> <goal>schemagen</goal> </goals> <configuration> <includes> <include>**/*DTO.java</include> <include>**/*Type.java</include> <include>**/*Status.java</include> </includes> <verbose>true</verbose> </configuration> </execution>