Configure the DMN engine

// create the process engine configuration
ProcessEngineConfigurationImpl processEngineConfiguration = // ...
    
// create the DMN engine configuration    
DefaultDmnEngineConfiguration dmnEngineConfiguration = (DefaultDmnEngineConfiguration) 
  DmnEngineConfiguration.createDefaultDmnEngineConfiguration();

// configure the DMN engine ...
// e.g. set the default expression language for input expressions to `groovy`
dmnEngineConfiguration.setDefaultInputExpressionExpressionLanguage("groovy");

// set the DMN engine configuration on the process engine configuration
processEngineConfiguration.setDmnEngineConfiguration(dmnEngineConfiguration);

// build the process engine which includes the DMN engine
processEngineConfiguration.buildProcessEngine();

<beans xmlns="http://www.springframework.org/schema/beans" 
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

  <bean id="processEngineConfiguration" 
        class="org.camunda.bpm.engine.impl.cfg.StandaloneProcessEngineConfiguration">
  
    <property name="dmnEngineConfiguration">
      <bean class="org.camunda.bpm.dmn.engine.impl.DefaultDmnEngineConfiguration">
        
        <!-- configure the DMN engine ... --> 
        <!-- e.g. set the default expression language for input expressions to `groovy` -->
        <property name="defaultInputExpressionExpressionLanguage" value="groovy" />
        
      </bean>
    </property>
    
  </bean>
</beans>