Problem with getVariable

[soennichsen]

Hi,

I'm having a problem when trying to read a process variable within a taskinstance.

The variable is set right after process instantiation:

ProcessInstance processInstance = jbpmContext.loadProcessInstance(processId);
ContextInstance contextInstance = processInstance.getContextInstance();
Activity activity = new Activity();
contextInstance.setVariable("init_arg", activity );

Here is the code to get the Variable within the TaskInstance:

ContextInstance contextInstance = taskInstance.getContextInstance();
Activity activity = (Activity) contextInstance.getVariable("init_arg");

When I try to read it in a TaskInstance, I get a

org.jbpm.JbpmException: couldn't deserialize object

Any ideas or hints?

Regards,
Sven

[hannes]

http://docs.jboss.com/jbpm/v3/userguide/context.html

The variable names are java.lang.String. By default, jBPM supports the following value types:

* java.lang.String
* java.lang.Boolean
* java.lang.Character
* java.lang.Float
* java.lang.Double
* java.lang.Long
* java.lang.Byte
* java.lang.Short
* java.lang.Integer
* java.util.Date
* byte[]
* java.io.Serializable
* classes that are persistable with hibernate

I guess your 'Activity' object implents none of that types. Make it serializable.

[soennichsen]

Found the solution for my problem:

My Activity class implemented already Serializable, but... I did not set the serialVersionUID like

private static final long serialVersionUID = 2175042348064562851L;

After doing so, getting the variable was not a problem ;-)

I had also problems with a ClassCastException sometimes, but setting the serialVersionUID seems to sovle this problem as well!

Regards,
Sven

[soennichsen]

Well, I was a little bit too quick: the problem is not solved!

When I cast the object to the correct class (Activity), I sometimes get a

j[list=]ava.lang.ClassCastException

or
[list=]org.jbpm.JbpmException: couldn't deserialize object

Why? Strange enough, that it worked for 2 or 3 times. I've experimented with the serialVersionUID to set it to the default or the a generated value, but I didn't help me.

Here is the code for Activity (now I used serialVersionUID = 1L):

/**
 * Container for an activity
 */
public class Activity implements java.io.Serializable {

 private static final long serialVersionUID = 1L;

 public boolean bApproved;

 public String taskId;

 public String processName;

 public String description;

 public String toString() {
 return "[Activity: bApproved=" + bApproved + "]";
 }
}

Regards,
Sven

[saviola]

Hi, Sven!
I would suggest you try serializing your Activity first and then set the serialized object through

contextInstance.setVariable(variableName, serializedValue)

I don't know if this is convinient approach to you but it worths trying it.

Regards,
Saviola