Question

I’m strugelling with an odd problem for days now.

Only one of the users of my webapp get an NoClassDefFoundError when trying to use some functionallity. This is the stacktrace:

java.lang.NoClassDefFoundError: com/sun/xml/bind/WhiteSpaceProcessor
    at com.sun.xml.bind.DatatypeConverterImpl._parseInt(DatatypeConverterImpl.java:105)
    at com.foo.bar.webservice.generated.GetLoginsRequest_JaxbXducedAccessor_panelId.parse(TransducedAccessor_field_Integer.java:32)
    at com.sun.xml.bind.v2.runtime.unmarshaller.StructureLoader.startElement(StructureLoader.java:166)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext._startElement(UnmarshallingContext.java:406)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.startElement(UnmarshallingContext.java:384)
    at com.sun.xml.bind.v2.runtime.unmarshaller.InterningXmlVisitor.startElement(InterningXmlVisitor.java:35)
    at com.sun.xml.bind.v2.runtime.unmarshaller.SAXConnector.startElement(SAXConnector.java:101)
    at com.sun.xml.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:224)
    at com.sun.xml.bind.unmarshaller.DOMScanner.scan(DOMScanner.java:107)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:289)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:272)
    at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:106)
    at org.springframework.oxm.jaxb.Jaxb2Marshaller.unmarshal(Jaxb2Marshaller.java:424)

On a strange way WhiteSpaceProcessor can’t be found while it is on the classpath.
I used tattletale to look at the possitions of the usage of the classes:

WhiteSpaceProcessor only exist once on the classpath:

DatatypeConverterImpl only exist once on the classpath

I’m stuck on the fact that the exact war on a different environment is working perfect.

working environment:

• Windows machine
• Tomcat 5.5.28
• Java 5 (jdk1.5.0.22)

none working environment:

• Linux machine
• Tomcat 5.5.??
• Java 5 (jdk1.5.0.22)

I hope somebody can sent me in the right direction.

tomcat server is already restarted

Answer 1

Did you use tattletale on the working or non-working machine?

Perhaps the failing environment contains some jar file in jre/lib/ext (or a similar extensions directory), and that’s being used in preference to a “lower down” version?

EDIT: Just to go into a bit more detail about the situations in which NoClassDefFoundError can be thrown, it’s worth reading the JVM spec, chapter 5. It talks about three situations:

• The resource corresponding to the class can’t be found at all
• The resource is found, but doesn’t correspond to the right class (although in that case I’d expect a message including “wrong name”)
• You’re using a version of Java earlier than 1.2, and the class file has an unsupported major/minor version number. (This situation now throws UnsupportedClassVersionError.)

Also read section 2.17.5: it states that if the class is in an “erroneous state” (e.g. previously initialization failed, or there was a bytecode verification failure) then NoClassDefFoundError will be thrown.

Now, if the static initializer of the class fails then the first caller sees an ExceptionInInitializerError – but the second caller sees NoClassDefFoundError. Here’s a short but complete program to demontrate this:

class Foo {
    static {
        if (true) {
            throw new RuntimeException();
        }
    }

    static void foo() {
    }
}

public class Test {

    public static void main(String[] args) {
        try {
            Foo.foo();
        } catch (Throwable t) {
            System.out.println("First exception: " + t);
        }
        try {
            Foo.foo();
        } catch (Throwable t) {
            System.out.println("Second exception: " + t);
        }
    }
}

Now unless something in your system is suppressing the ExceptionInInitializerError, I’d expect to see that in the log before NoClassDefFoundError if that were the problem. I still think it’s more likely that your failing system is loading one class in an extension classloader which then can’t find the ShiteSpaceProcessor class.