java.lang.NoClassDefFoundError: Could not initialize class org.apache.poi.POIXMLDocument on Jboss 5.0 EAP

apache-poi, java, jboss5.x, jsf-1.2

Solution

It looks like you're application is throwing the exception you're seeing because an Apache XMLBeans JAR or class is not present when running under JBoss 5.0. It seems Apache POI is trying to load the class `org.apache.xmlbeans.XMLOptions` but it cannot find this class.

The message `Could not initialize class SomeClass` indicates that the JVM has twice tried and failed to load and statically initialize the class `SomeClass`. In this case, the class in question is `org.apache.poi.POIXMLDocument`.

Static initialization for a class consists of statically initializing its superclass, assigning values to all `static` fields and running all `static` initializer blocks. The POIXMLDocument class has a few `static` `String` constants, which won't cause any problem, but no static initializer. It is however a subclass of POIXMLDocumentPart, which is a subclass of `Object` and which has the following static initialization code:

    private static POILogger logger = POILogFactory.getLogger(POIXMLDocumentPart.class);

    public static final XmlOptions DEFAULT_XML_OPTIONS;
    static {
        DEFAULT_XML_OPTIONS = new XmlOptions();
        DEFAULT_XML_OPTIONS.setSaveOuter();
        DEFAULT_XML_OPTIONS.setUseDefaultNamespace();
        DEFAULT_XML_OPTIONS.setSaveAggressiveNamespaces();
    }

This static initialization will fail if the JVM cannot load all of the `POILogger`, `POILogFactory` and `XmlOptions` classes.

The `POILogger` and `POILogFactory` classes are both imported from the package `org.apache.poi.util.POILogFactory`, and both classes are contained within poi-3.7.jar, so they're not the problem here. So, by elimination, it seems the `XmlOptions` class, `import`ed from `org.apache.xmlbeans.XmlOptions`, must be missing.

I found this `XMLOptions` class within `xbean.jar` contained within the `lib` folder of `xmlbeans-2.6.0.zip` downloadable from one of the mirrors here.

It seems likely to me that adding this JAR will fix the problem on JBoss 5.0 EAP. However, I'm aware you said your application works fine in JBoss 5.1 GA, which implies to me that JBoss 5.1 GA contains a copy of this JAR whereas 5.0 EAP doesn't. As a result I'm not sure what the best way to fix this problem is. I'd be hesitant to add this XMLBeans JAR to your application as doing so may cause issues when you run it under JBoss 5.1. I don't know whether there's a way of adding extra 'library' JARs to JBoss 5.0, though - perhaps that's worth looking at?

Problem

Original source