flowable/flowable-engine · error · FlowableException

Several JAXB binding definitions found for flowable-cxf: "…

Error message

Several JAXB binding definitions found for flowable-cxf: " + CxfWSDLImporter.JAXB_BINDINGS_RESOURCE

What it means

The CxfWebServiceClient constructor locates the JAXB bindings resource (CxfWSDLImporter.JAXB_BINDINGS_RESOURCE) on the classpath. If more than one resource with that name is found, the classpath is ambiguous, so construction fails fast. The library expects exactly zero-or-one (and treats zero as a separate error).

Solutions

1. Inspect the classpath (e.g. ClassLoader.getResources on the resource name) and remove the duplicate jar/module containing the extra bindings file.
2. If building a fat jar, exclude duplicate copies of the resource via shading exclusions.
3. Ensure only the flowable-cxf module's own bindings resource is packaged.

Example fix

// before: both flowable-cxf and a copied legacy ode jar on classpath
classpath: flowable-cxf.jar, ode-old.jar (contains same bindings resource)
// after: remove ode-old.jar or exclude the resource
<exclusion><groupId>org.apache.ode</groupId><artifactId>ode-old</artifactId></exclusion>

Enumeration<URL> urls = Thread.currentThread().getContextClassLoader()
    .getResources("org/flowable/cxf/bindings.xml"); // CxfWSDLImporter.JAXB_BINDINGS_RESOURCE
int count = 0;
while (urls.hasMoreElements()) { urls.nextElement(); count++; }
if (count > 1) throw new IllegalStateException("Duplicate JAXB bindings resources on classpath: " + count);

try { new CxfWebServiceClient(wsdl); } catch (FlowableException e) { if (e.getMessage().contains("Several JAXB binding definitions")) { /* dedupe classpath */ } else { throw e; } }

When it happens

Trigger: Constructing new CxfWebServiceClient(wsdl) when two or more JAXB_BINDINGS_RESOURCE files exist on the classpath.

Common situations: Multiple jars on the classpath each bundling the same bindings resource, fat/uber jars merging resources, or duplicate module dependencies in a Flowable app.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

• Several JAXB binding definitions found for flowable-cxf: "…
• Error retrieving the JAXB binding definitions
• The JAXB binding definitions are not found for…
• The JAXB binding definitions are not found for…
• An error occurs creating a web-service client for WSDL '" +…

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/2817b63a8b3596b5. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-cxf/src/main/java/org/flowable/engine/impl/webservice/CxfWebServiceClient.java:52

 * 
 * @author Esteban Robles Luna
 */
public class CxfWebServiceClient implements SyncWebServiceClient {

    private static final Logger LOGGER = LoggerFactory.getLogger(CxfWebServiceClient.class);

    protected Client client;

    public CxfWebServiceClient(String wsdl) {
        JaxWsDynamicClientFactory dcf = JaxWsDynamicClientFactory.newInstance();
        Enumeration<URL> xjcBindingUrls;
        try {
            xjcBindingUrls = Thread.currentThread().getContextClassLoader()
                    .getResources(CxfWSDLImporter.JAXB_BINDINGS_RESOURCE);
            if (xjcBindingUrls.hasMoreElements()) {
                final URL xjcBindingUrl = xjcBindingUrls.nextElement();
                if (xjcBindingUrls.hasMoreElements()) {
                    throw new FlowableException("Several JAXB binding definitions found for flowable-cxf: "
                            + CxfWSDLImporter.JAXB_BINDINGS_RESOURCE);
                }
                this.client = dcf.createClient(wsdl, Arrays.asList(new String[] { xjcBindingUrl.toString() }));
                this.client.getRequestContext().put("org.apache.cxf.stax.force-start-document", Boolean.TRUE);
            } else {
                throw new FlowableException("The JAXB binding definitions are not found for flowable-cxf: "
                        + CxfWSDLImporter.JAXB_BINDINGS_RESOURCE);
            }
        } catch (IOException e) {
            throw new FlowableException("An error occurs creating a web-service client for WSDL '" + wsdl + "'.", e);
        }
    }

    @Override
    public Object[] send(String methodName, Object[] arguments, ConcurrentMap<QName, URL> overridenEndpointAddresses) throws Exception {
        try {
            URL newEndpointAddress = null;
            if (overridenEndpointAddresses != null) {

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