Evaluation of an uploaded DMN-file fails: DMN-01002 Unable to evaluate expression for language 'juel':


currently we have to use Camunda in the version 7.5. We would like to deploy a DMN-File from an inputStream and evaluate it. The deployment seems to be working, but the evaluation fails with an error in the evaluation-process. (See comment in the code).

Here is the DMN-File (it works in the DMN-Cloud - so it is valid) dmnColor.dmn (1.0 KB)

Here is the code to deploy and evaluate the resource:

String decisionDefinitionKey = "dmnColor";
String decisionDefinitionName = "colorDefinitionName";

// Read the file
InputStream decisionDefinitionStream= this.getClass().getResourceAsStream("/META-INF/dmn/dmnColor.dmn");

// Getting the content of the file in plain-text org.apache.commons.io.IOUtils
String clearTextContent = IOUtils.toString(decisionDefinitionStream, Charset.defaultCharset().name()); 

decisionDefinitionStream = new ByteArrayInputStream(clearTextContent.getBytes(StandardCharsets.UTF_8));
DmnModelInstance dmnModelInstance = Dmn.readModelFromStream(decisionDefinitionStream);
// Validiate the model - works fine

// Add .dmn to the file, if it not exists
String resourceName = decisionDefinitionName.endsWith(".dmn") ? decisionDefinitionName : decisionDefinitionName + ".dmn";

/* deploy the resource
The deployment seems to be working, there is a deployment in the database. 
Normally we would use addModelInstance, but in version 7.5 this method is not available for DmnInstances. So we ar e using add String*/
this.processEngine.getRepositoryService().createDeployment().name(decisionDefinitionName).addString(resourceName, clearTextContent).deploy();

VariableMap variables = Variables.createVariables().putValue("gender", "female");

// Evaluate the decision - it fails with the error
> org.camunda.bpm.engine.ProcessEngineException: Exception while evaluating decision with key 'dmnColor'
> org.camunda.bpm.dmn.engine.impl.DmnEvaluationException: DMN-01002 Unable to evaluate expression for language 'juel': '${gender}'
DmnDecisionTableResult colorDecisionResult = this.processEngine.getDecisionService().evaluateDecisionTableByKey(decisionDefinitionKey, variables);`

Here is the full stacktrace:

> Caused by: org.camunda.bpm.dmn.engine.impl.DmnEvaluationException: DMN-01002 Unable to evaluate expression for language 'juel': '${gender}'
>         at org.camunda.bpm.dmn.engine.impl.DmnEngineLogger.unableToEvaluateExpression(DmnEngineLogger.java:32)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateElExpression(DefaultDmnDecisionContext.java:329)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateExpression(DefaultDmnDecisionContext.java:297)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateInputExpression(DefaultDmnDecisionContext.java:217)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateInput(DefaultDmnDecisionContext.java:112)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateDecisionTable(DefaultDmnDecisionContext.java:93)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnEngine.evaluateDecisionTable(DefaultDmnEngine.java:95)
>         at org.camunda.bpm.engine.impl.dmn.invocation.DecisionTableInvocation.invoke(DecisionTableInvocation.java:52)
>         at org.camunda.bpm.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:54)
>         at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocationInContext(DefaultDelegateInterceptor.java:87)
>         at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:59)
>         at org.camunda.bpm.engine.impl.util.DecisionTableUtil.invoke(DecisionTableUtil.java:86)
>         at org.camunda.bpm.engine.impl.util.DecisionTableUtil.evaluateDecisionTable(DecisionTableUtil.java:81)
>         at org.camunda.bpm.engine.impl.dmn.cmd.EvaluateDecisionCmd.doEvaluateDecision(EvaluateDecisionCmd.java:72)
>         ... 48 more
> Caused by: org.camunda.bpm.engine.impl.javax.el.PropertyNotFoundException: Cannot resolve identifier 'gender'
>         at org.camunda.bpm.engine.impl.juel.AstIdentifier.eval(AstIdentifier.java:83)
>         at org.camunda.bpm.engine.impl.juel.AstEval.eval(AstEval.java:50)
>         at org.camunda.bpm.engine.impl.juel.AstNode.getValue(AstNode.java:26)
>         at org.camunda.bpm.engine.impl.juel.TreeValueExpression.getValue(TreeValueExpression.java:114)
>         at org.camunda.bpm.engine.impl.dmn.el.ProcessEngineElExpression.getValue(ProcessEngineElExpression.java:43)
>         at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateElExpression(DefaultDmnDecisionContext.java:325)

What i’am doing wrong here? The DMN-File is validated successfully, the deployment seems to be working, but if i want to evaluate it, it throws this exception. My input expression in the DMN file is called ‘gender’. The dmn-file is working fine here : Camunda Cloud.

UPDATE: It seems to be, that there is an issue in the bindings in the class > org.camunda.bpm.engine.impl.juel.AstIdentifier:line77 →

method public Object eval(Bindings bindings, ELContext context) {
		ValueExpression expression = bindings.getVariable(index); // bindings have no variables. So expression contains null;

Maybe there is a bug in the class org.camunda.bpm.engine.impl.juel.TreeValueExpression in line 65?

this.bindings = tree.bind(functions, variables, converter); // Bindings are not set correctly

Additionally i have to say, that we are using the camunda osgi-extension . Can this be a bug from the extension? But the extension is supporting Camunda 7.5…

Thanks a lot for your help!

Could you provide a test case that reproduces this behavior? Here is a template Maven project to get started: https://github.com/camunda/camunda-engine-unittest


I was able to upload your dmn file via the rest api and evaluate it successfully.

However, I get the error you desribe if I am using a DRD and I have the dependency arrow in the wrong direction. Hence is this simple decision table failing or is it part of a DRD?’



Thank you for your quick replies. I’am using a simple DMN-File. I have created a testcase with the same code here and it works fine. I am assuming, that it is a problem with the OSGi-extension, we are using. It would be really grateful if someone can try to evaluate a DMN-file within OSGi. I have created an issue for that. We can continue with the discussion there.