org.kie.remote.services.rest.jaxb

Class DynamicJaxbContext

java.lang.Object

javax.xml.bind.JAXBContext

org.kie.remote.services.rest.jaxb.DynamicJaxbContext

@ApplicationScoped
public class DynamicJaxbContext
extends JAXBContext

READ THIS BEFORE WORKING ON THIS CLASS!

There are a couple of hidden issues that this class deals this:

1. JAXBContext instances are cached by the REST framework (and then reused with *all* request). This means that we can not provide multiple JAXBContext instances, but must make sure that an instance of this class is cached -- which will then provide different (un)marshallers depending on the deploymentId used in the request.
   This means that when the extended methods are called (JAXBContext.createMarshaller() for example), we then look at the internal cache to retrieve the correct JAXBContext).
2. Different deployments may have different versions of the same class. This means that We can not use 1 (internally cached) JAXBContext instance to deal with all deployments. Tests have been specifically created to test this issue.
3. Concurrency: this is an application scoped class that is being acted on by multiple REST request threads. Fortunately, we just handle normal REST requests (no comet, for example), so the requests themselves (with regards to the serializaiton logic) are all handled in one thread.

With regards to classloading and related issues, these rules apply:

1. Implementations are open-ended; anyone can implement those interfaces, even by different people from different modules, provided they are all given to the JAXBContext.newInstance method. There's no need to list all the implementation classes in anywhere. Each implementation of the interface needs to have an unique element name. Every reference to interface needs to have the XmlElementRef annotation. The type=Object.class portion tells JAXB that the greatest common base type of all implementations would be java.lang.Object. In all cases, please preserve existing tests when modifying this class!

Field Summary

Fields inherited from class javax.xml.bind.JAXBContext

JAXB_CONTEXT_FACTORY

Constructor Summary

Constructors

Constructor and Description
DynamicJaxbContext()

Method Summary

Methods

Modifier and Type	Method and Description
void	addOnDeploy(org.jbpm.services.api.DeploymentEvent event) Called when the workbench/console/business-central deploys a new deployment.
static void	clearDeploymentJaxbContext()
Marshaller	createMarshaller()
Unmarshaller	createUnmarshaller()
Validator	createValidator()
Collection<Class<?>>	getDeploymentClasses(String deploymentId) Used by classes involved with de/serialzation in order to retrieve (user-defined) clases to be used in de/serialization.
JAXBContext	getDeploymentJaxbContext(String deploymentId)
void	removeOnUnDeploy(org.jbpm.services.api.DeploymentEvent event) Called when the workbench/console/business-central *un*deploys (removes) a deployment.
static void	setDeploymentJaxbContext(String deploymentId)

Methods inherited from class javax.xml.bind.JAXBContext

createBinder, createBinder, createJAXBIntrospector, generateSchema, newInstance, newInstance, newInstance, newInstance, newInstance

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DynamicJaxbContext

public DynamicJaxbContext()

Method Detail

setDeploymentJaxbContext

public static void setDeploymentJaxbContext(String deploymentId)

clearDeploymentJaxbContext

public static void clearDeploymentJaxbContext()

addOnDeploy

public void addOnDeploy(@Observes
               org.jbpm.services.api.DeploymentEvent event)

Called when the workbench/console/business-central deploys a new deployment.

Parameters:

event -

removeOnUnDeploy

public void removeOnUnDeploy(@Observes
                    org.jbpm.services.api.DeploymentEvent event)

Called when the workbench/console/business-central *un*deploys (removes) a deployment.

Removes the cached JAXBContext and deployment lock object

It's VERY important that the cached JAXBContext instance be removed! The new deployment may contain a different version of a class with the same name. Keeping the old class definition will cause problems!

Parameters:

event - The DeploymentEvent fired on an undeploy of a deployment

createUnmarshaller

public Unmarshaller createUnmarshaller()
                                throws JAXBException

Specified by:

createUnmarshaller in class JAXBContext

Throws:

JAXBException

createMarshaller

public Marshaller createMarshaller()
                            throws JAXBException

Specified by:

createMarshaller in class JAXBContext

Throws:

JAXBException

createValidator

public Validator createValidator()
                          throws JAXBException

Specified by:

createValidator in class JAXBContext

Throws:

JAXBException

getDeploymentClasses

public Collection<Class<?>> getDeploymentClasses(String deploymentId)

Used by classes involved with de/serialzation in order to retrieve (user-defined) clases to be used in de/serialization.

Parameters:

deploymentId - The deployment unit id

Returns:

A Collection of Classes that are in the deployment unit

getDeploymentJaxbContext

public JAXBContext getDeploymentJaxbContext(String deploymentId)