flowable/flowable-engine · error · FlowableException

Could not find importer class for type " + theImport.getImpo

Error message

Could not find importer class for type " + theImport.getImportType()

What it means

DefaultXMLImporterFactory.createXMLImporter imports WSDL/XML definitions for BPEL-style service tasks by reflectively loading a default importer class (DEFAULT_XML_IMPORTER_FACTORY_CLASSNAME) via the thread context classloader. If the class is not on the classpath, ClassNotFoundException is wrapped and a FlowableException 'Could not find importer class for type <importType>' is thrown. This is a deployment/classpath problem, not an invalid import type value.

Source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/bpmn/parser/factory/DefaultXMLImporterFactory.java:39

 * Default implementation of the {@link XMLImporterFactory}. Used when no custom {@link XMLImporterFactory} is injected
 * on the {@link ProcessEngineConfigurationImpl}.
 * 
 * @author Christophe DENEUX
 */
public class DefaultXMLImporterFactory implements XMLImporterFactory {

    // Name of the default XML Importer, provided by flowable-cxf
    private static final String DEFAULT_XML_IMPORTER_FACTORY_CLASSNAME = "org.flowable.engine.impl.webservice.CxfWSDLImporter";

    @Override
    public XMLImporter createXMLImporter(Import theImport) throws FlowableException {

        try {
            Class<?> wsdlImporterClass = Class.forName(DEFAULT_XML_IMPORTER_FACTORY_CLASSNAME, true,
                    Thread.currentThread().getContextClassLoader());
            return (XMLImporter) wsdlImporterClass.getConstructor().newInstance();
        } catch (ClassNotFoundException e) {
            throw new FlowableException("Could not find importer class for type " + theImport.getImportType(), e);
        } catch (Exception e) {
            throw new FlowableException(String.format("Error instantiating XML importer '%s' for type '%s'",
                    DEFAULT_XML_IMPORTER_FACTORY_CLASSNAME, theImport.getImportType()), e);
        }
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

Add the artifact that provides DEFAULT_XML_IMPORTER_FACTORY_CLASSNAME (the XML/WSDL importer) to the runtime classpath.
Verify the class can be loaded from the current thread context classloader (Class.forName in your app) and fix classloader/scoping issues (e.g. remove provided scope or shade exclusions).
Remove the <import> declaration from the BPMN if the WSDL/XML import is not actually needed.
If the importer class name was customized, ensure the configured class exists and is exported by its jar.

Example fix

// before (pom.xml)
<dependency>
  <groupId>org.flowable</groupId>
  <artifactId>flowable-xml-importer</artifactId>
  <scope>provided</scope> <!-- not available at runtime -->
</dependency>
// after
<dependency>
  <groupId>org.flowable</groupId>
  <artifactId>flowable-xml-importer</artifactId>
  <scope>runtime</scope>
</dependency>

Defensive patterns

Strategy: try-catch

Validate before calling

try {
    Class.forName("org.flowable.engine.impl.bpmn.parser.factory.DefaultXmlImporter",
        true, Thread.currentThread().getContextClassLoader());
} catch (ClassNotFoundException e) {
    throw new IllegalStateException("WSDL/XML importer not on classpath; add the importer dependency", e);
}

Try / catch

try {
    deploymentBuilder.deploy();
} catch (FlowableException e) {
    if (e.getMessage().startsWith("Could not find importer class")) {
        // add the missing importer jar / fix the classloader, then retry deployment
    } else { throw e; }
}

Prevention

Include the XML/WSDL importer dependency in runtime scope whenever BPMN <import> declarations are used.
Smoke-test deployments in CI so classpath regressions are caught before production.
Check thread context classloader behavior when embedding Flowable in app servers or shaded jars.
Remove unused <import> elements from process definitions.

When it happens

Trigger: Deploying a process containing a service task with an XML/WSDL import declaration while the module providing the XML importer class (e.g. flowable-bpel or the wsdl importer jar) is absent from the application classpath, or the thread context classloader cannot see it.

Common situations: Running Flowable in an app server or fat jar where the optional importer dependency was excluded; shade-plugin or dependency scoping (provided/test) dropping the importer; switching from the full flowable-engine-war distribution to an embedded setup without the extra jar.

Related errors

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/f81770702c2ad0ca. Report an issue: GitHub.