de.danet.an.workflow.api
Class WorkflowServiceFactory

java.lang.Object
  extended byde.danet.an.workflow.api.WorkflowServiceFactory

public abstract class WorkflowServiceFactory
extends java.lang.Object

This class provides a factory API that enables clients to obtain a workflow service facility.

Version:
$Revision: 2314 $
Author:

Constructor Summary
protected WorkflowServiceFactory()
          Constructor.
 
Method Summary
protected  java.util.Map getProperties()
          Used by derived classes to access the properties.
static WorkflowServiceFactory newInstance()
          Obtain a new instance of a WorkflowServiceFactory.
abstract  WorkflowService newWorkflowService()
          Creates a new instance of a WorkflowService.
 void setProperties(java.util.Map props)
          A convenience method that sets all properties in the Map.
 void setProperty(java.lang.String name, java.lang.Object value)
          Sets a property which is passed to the WorkflowService produced by this factory.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

WorkflowServiceFactory

protected WorkflowServiceFactory()
Constructor. Must be overridden with a parameterless public constructor by derived class.

Method Detail

newInstance

public static WorkflowServiceFactory newInstance()
                                          throws FactoryConfigurationError
Obtain a new instance of a WorkflowServiceFactory. This static method creates a new factory instance. The method uses the following ordered lookup procedure to determine the WorkflowServiceFactory implementation class to load: Note that the specified workflow service factory may need additional configuration parameters.

Returns:
an instance of the WorkflowServiceFactory.
Throws:
FactoryConfigurationError - if a factory instance can't be created.

setProperty

public void setProperty(java.lang.String name,
                        java.lang.Object value)
Sets a property which is passed to the WorkflowService produced by this factory.

Valid properties generally depend on the underlying implementation. There are, however, a few exceptions.

If the workflow service implementation is based on the J2EE environment, clients derive the connection to a server from an InitialContext. There are cases when the user wants or needs to override the initial context used by the workflow service implementation. It is therefore defined that setting the property "javax.naming.InitialContext" to a value of type Context overrides any default method used by the workflow service implementation to obtain the initial context.

As an alternative, the property "javax.naming.InitialContext.Environment" may be set to a Hashtable that contains the environment to be used when creating an InitialContext.

Subsequent versions of this interface may define additional common properties. We therefore recommended to use "fully qulified" (i.e. package style) names for properties that are specific to a workflow service implementation.

Parameters:
name - the name of the property
value - the value of the property

setProperties

public void setProperties(java.util.Map props)
A convenience method that sets all properties in the Map.

Parameters:
props - the properties to be set

getProperties

protected java.util.Map getProperties()
Used by derived classes to access the properties.

Returns:
the defined properties

newWorkflowService

public abstract WorkflowService newWorkflowService()
                                            throws FactoryConfigurationError
Creates a new instance of a WorkflowService.

This API does not specify how a workflow service factory or workflow service should be implemented. If, however, the implementation is J2EE/EJB based, the following additional rules apply to achieve common bahaviour for J2EE based implementations.

In the J2EE environment, clients usually obtain the connection to a server from a directory service represented by an InitialContext instance. This instance need not be the default initial context available to the client (think of a servlet running in a servlet container that wants to access the workflow engine running in an application server on a different machine).

In an environment that uses an InitialContext to obtain the connection to the server (as described above), the following ordered lookup procedure must be implemented to determine this initial context.

Returns:
the workflow service.
Throws:
FactoryConfigurationError - if not all required resources can be obtained.