Groovy Script Task serialize error with HTTPBuilder

[gavnunns]

Hello, I am trying to write a script task in Groovy that implements a simple REST client to query a web service.  The script works outside of the script task with the same environment that the engine is running in.

—
import groovyx.net.http.RESTClient
freedom = new RESTClient( 'http://api:api@localhost:8080/freedom/api/activiti/' )
def resp = freedom.get( path : '19' )
println resp.data.toString()
—

However I'm getting the following error which indicates it can't serialize the RESTClient.  If the problem is everything within a script needs to the serialized can anyone offer an alternative solutions to calling an external REST service from a Activiti Task.

Thanks

Error is show below.
—
org.activiti.engine.ActivitiException: problem evaluating script: javax.script.ScriptException: org.activiti.engine.ActivitiException: couldn't find a variable type that is able to serialize groovyx.net.http.RESTClient@5d70c00f
   at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:77)
   at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:64)
   at org.activiti.engine.impl.bpmn.behavior.ScriptTaskActivityBehavior.execute(ScriptTaskActivityBehavior.java:63)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:44)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:66)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:36)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:365)
   at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:105)
   at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:54)
   at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44)
   at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.execute(FlowNodeActivityBehavior.java:36)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:44)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStartInitial.eventNotificationsCompleted(AtomicOperationProcessStartInitial.java:46)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStart.eventNotificationsCompleted(AtomicOperationProcessStart.java:45)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:86)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:530)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:525)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:320)
   at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:83)
   at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:36)
   at org.activiti.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:24)
   at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:61)
   at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:37)
   at org.activiti.engine.impl.RuntimeServiceImpl.startProcessInstanceById(RuntimeServiceImpl.java:78)
   at ActivitiAgent.ActivitiHandler.startTask(ActivitiHandler.java:78)
   at ActivitiAgent.Activiti$Processor$startTask.getResult(Activiti.java:719)
   at ActivitiAgent.Activiti$Processor$startTask.getResult(Activiti.java:704)
   at org.apache.thrift.ProcessFunction.process(ProcessFunction.java:39)
   at org.apache.thrift.TBaseProcessor.process(TBaseProcessor.java:39)
   at org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:225)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
   at java.lang.Thread.run(Thread.java:724)
Caused by: javax.script.ScriptException: javax.script.ScriptException: org.activiti.engine.ActivitiException: couldn't find a variable type that is able to serialize groovyx.net.http.RESTClient@5d70c00f
   at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.eval(GroovyScriptEngineImpl.java:152)
   at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:233)
   at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:75)
   … 71 more
Caused by: javax.script.ScriptException: org.activiti.engine.ActivitiException: couldn't find a variable type that is able to serialize groovyx.net.http.RESTClient@5d70c00f
   at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.eval(GroovyScriptEngineImpl.java:349)
   at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.eval(GroovyScriptEngineImpl.java:146)
   … 73 more
Caused by: org.activiti.engine.ActivitiException: couldn't find a variable type that is able to serialize groovyx.net.http.RESTClient@5d70c00f
   at org.activiti.engine.impl.variable.DefaultVariableTypes.findVariableType(DefaultVariableTypes.java:62)
   at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.createVariableInstance(VariableScopeImpl.java:359)
   at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.createVariableLocal(VariableScopeImpl.java:292)
   at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.createVariableLocal(VariableScopeImpl.java:279)
   at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.setVariable(VariableScopeImpl.java:254)
   at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.setVariable(VariableScopeImpl.java:237)
   at org.activiti.engine.impl.scripting.ScriptBindings.put(ScriptBindings.java:83)
   at javax.script.SimpleScriptContext.setAttribute(SimpleScriptContext.java:228)
   at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl$1.setVariable(GroovyScriptEngineImpl.java:282)
   at groovy.lang.Script.setProperty(Script.java:66)
   at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.setGroovyObjectProperty(ScriptBytecodeAdapter.java:528)
   at Script3.run(Script3.groovy:3)
   at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.eval(GroovyScriptEngineImpl.java:346)
   … 74 more

[frederikherema1]

THe REST-client is treated as a variable and is tried to be stored, while you don't want that. Userguide says:


<activiti:executionListener event="start" class="org.activiti.engine.impl.bpmn.listener.ScriptExecutionListener" >
  <activiti:field name="script">
    <activiti:string>
      def bar = "BAR";  // local variable
      foo = "FOO"; // pushes variable to execution context
      execution.setVariable("var1", "test"); // test access to execution instance
      bar // implicit return value
    </activiti:string>
  </activiti:field>
  <activiti:field name="language" stringValue="groovy" />
  <activiti:field name="resultVariable" stringValue="myVar" />
<activiti:executionListener>

So use "def" instead, when declaring the REST-client, so it's not treated as a process-variable.

[gavnunns]

Perfect, that was it, thanks for the rapid and clear response

[frederikherema1]

No worries, glad to help