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https://jira.jboss.org/jira/browse/JBPM-1914?page=com.atlassian.jira.plug...
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Mauro Molinari commented on JBPM-1914:
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We are using jBPM 3.2.6.SP1 now and the problem didn't arise again in the
"normal" use, although we didn't test it in depth. However, when managing
Log instances it still happens.
Suppose I have a VariableUpdateLog instance; then, in the following code:
VariableUpdateLog variableLog = // my VariableUpdateInstance
VariableInstance variable = variableLog.getVariableInstance();
String name = variable.getName();
Object oldValue = variableLog.getOldValue();
Object newValue = variableLog.getNewValue();
In this case, both oldValue and newValue are always ByteArrays... It's a bit
complicated to isolate a simple test case, however our application is analyzing all the
log entries in a process instance, iterating over them and displaying an appropriate
message for each of them on a JSP. In the case of a VariableUpdateLog entry, the old an
new values of the variable that has been updated are written on the JSP. And, as I said,
we always get the JSP to write a toString of a ByteArray instance...
This doesn't happen with VariableCreateLog instances...
I don't know if this is the same problem of the original bug report or it is another.
Problem in retrieving variables of Serializable objects
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Key: JBPM-1914
URL:
https://jira.jboss.org/jira/browse/JBPM-1914
Project: jBPM
Issue Type: Bug
Security Level: Public(Everyone can see)
Components: Runtime Engine
Affects Versions: jBPM 3.3.0 GA
Reporter: Mauro Molinari
Assignee: Alejandro Guizar
Fix For: jBPM 3.2.6 GA
I have encountered a serious problem working with variables whose value is a serializable
object.
The problem is that sometimes (not always!) an error like the following is given when
retrieving a variable:
java.lang.ClassCastException: org.jbpm.bytes.ByteArray$$EnhancerByCGLIB$$cc67d06e
The code is like:
MySerializableClass obj = (MySerializableClass)
contextInstance.getVariable("myVariable");
(of course, "myVariable" is a variable that I previously have set with a
MySerializableClass object)
Apart from the CGLIB awful problem with proxies, even if I extract the value from the
proxy with the following:
public static Object getCGLIBProxiedObject(final Object proxy)
{
if(proxy instanceof HibernateProxy)
{
final LazyInitializer initializer =
((HibernateProxy) proxy).getHibernateLazyInitializer();
return initializer.getImplementation();
}
return proxy;
}
the problem is that the variable value is retrieved as a org.jbpm.bytes.ByteArray instead
of a MyClass instance!
I did some debugging and discovered that:
- in org.jbpm.context.exe.VariableContainer.getVariable(String), when
org.jbpm.context.exe.VariableContainer.hasVariableLocally(String) is called, Hibernate
lazily retrieves a org.jbpm.context.exe.variableinstance.ByteArrayInstance instance from
the database and creates it using its empty constructor
- unfortunately, when a org.jbpm.context.exe.VariableInstance (extended by
ByteArrayInstance) is constructed using its constructor, its converter instance variable
remains null
- the VariableInstance converter instance variable is set to something only when a
VariableInstance is created using org.jbpm.context.exe.JbpmType.newVariableInstance(), but
this is not the case when a VariableInstance is lazily loaded by Hibernate; in fact, in my
case, org.jbpm.context.exe.JbpmType.newVariableInstance() is never called and the
converter field of my ByteArrayInstance instance is always null!
- this causes org.jbpm.context.exe.VariableInstance.getValue() to return the value given
by org.jbpm.context.exe.variableinstance.ByteArrayInstance.getObject() without applying
the necessary conversion (deserialization)
Please note that my variable values are stored in jBPM database in JBPM_VARIABLEINSTANCE
table with the CONVERTER column correctly populated with "R".
I think this is a critical problem. By now, the only workaround I have found is to always
apply the following utility method when retrieving variable values, before returning them
to the client code:
public static Object extractVariableValue(final Object rawValue)
{
Object result = CardinisJbpmUtilities.getCGLIBProxiedObject(rawValue);
if(result instanceof ByteArray)
try
{
result =
new ObjectInputStream(new ByteArrayInputStream(((ByteArray) result)
.getBytes())).readObject();
}
catch(final Exception e)
{
throw new RuntimeException(e);
}
return result;
}
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