Package org.apache.commons.workflow

This package contains the core interfaces and classes that define the major components of the workflow management system.


Interface Summary
Activity An Activity represents an ordered sequence of Steps that comprise the executable actions necessary to accomplish a business task.
Block A Block is a Step that can include nested Steps.
Context A Context represents the dynamic computational state of a workflow process that is currently being executed.
ContextListener A ContextListener registers its interest in receiving ContextEvent notifications when the occur on a particular Context of interest.
Descriptor A Descriptor is a description of the mechanism by which an arbitrary Java object (typically a JavaBean) is referenced.
Descriptors Implementing Descriptors indicates that the corresponding object has an associated list of Descriptor objects associated with it, which can be manipulated through the methods defined in this interface.
Iterator An Iterator is a Block that conditionally repeats the nested Steps associated with the Block more than once (such as a Block that implements "while" or "for" functionality).
Owner Owner represents the common characteristics of Activities and Blocks (that is, Steps that allow nested Steps, such as those that implementat conditionals and iteration).
Registry A Registry is a Singleton that provides registration and lookup facilities for Activity instances.
Scope A Scope is a collection of arbitrary Java objects, keyed by String-valued names.
ScopeListener A ScopeListener registers its interest in receiving ScopeEvent notifications when the occur on a particular Scope of interest.
Step A Step represents a single executable action that can occur during the completion of an Activity.

Class Summary
BlockState BlockState represents the current dynamic execution state of a Block that is executing nested Steps.
ContextEvent A ContextEvent provides notification to a ContextListener that a specified event has occurred for the specified context.
ScopeEvent A ScopeEvent provides notification to a ScopeListener that a specified event has occurred for the specified scope.

Exception Summary
StepException A StepException is used to report problems encountered during the dynamic execution of a specific Step.
WorkflowException A WorkflowException is the base class for exceptions related to the workflow engine framework.

Package org.apache.commons.workflow Description

This package contains the core interfaces and classes that define the major components of the workflow management system. There are divided into several categories, as follows.

The static representation of a set of possible workflows is represented internally as a tree of objects that implement the following interfaces. There is a one-to-many relationship between each component and the one immediately below it.

The components described above are typically represented textually in an XML document whose format is not of interest to the core platform. However, the internal representation of these components is shared among concurrent users of those components, so the corresponding object tree (and the bean properties used to represent the linkages) should be considered read only after it is constructed.

The dynamic state of a computation is represented by the following components. Each "in progress" computation, whether executed by the same thread or different threads, must have its own Context to represent the current state.

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