com.gridsystems.nextgrid.api.pom
Class AbstractProcessImpl

java.lang.Object
  com.gridsystems.nextgrid.api.pom.PemHelper
      com.gridsystems.nextgrid.api.pom.ProcessImpl
          com.gridsystems.nextgrid.api.pom.AbstractProcessImpl

All Implemented Interfaces:

Enactable, java.io.Serializable, java.lang.Cloneable, nextgrid.api.pom.AbstractProcess, nextgrid.api.pom.Process

public final class AbstractProcessImpl
extends ProcessImpl
implements nextgrid.api.pom.AbstractProcess

A process with a semantic description, but no specific implementation binding details.

Such an abstract process must be fulfilled with binding information or "replaced" by a more specific, yet still abstract, process during enaction. This replacement is really implemented through a child containment structure to prevent losing original semantic data: In case of error, the enactor must be able to revert to the original abstract description and repeat the discovery phase to reach an alternative service provider.

The presence of instances of this class within a workflow representation as leaf nodes marks this workflow as abstract, meaning that it will require some extra process before being "executable".

In OWL-WS terms, an AbstractProcessImpl can be mapped to a service that only contains a profile, but no grounding; that is, it only states service constraints, but no capabilities.

Author:

Rodrigo Ruiz

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.gridsystems.nextgrid.api.pom.ProcessImpl

ProcessImpl.ValidationType

Field Summary

Fields inherited from class com.gridsystems.nextgrid.api.pom.ProcessImpl

DFA_INITIAL_STATE, ENACTOR_LOG

Fields inherited from interface nextgrid.api.pom.AbstractProcess

UNDEFINED_PRIORITY

Constructor Summary

AbstractProcessImpl()
Creates an instance.

AbstractProcessImpl(nextgrid.api.pom.QueryProfile profile)
Creates a new instance.

Method Summary

nextgrid.api.pom.Process	copy()
void	discover(nextgrid.api.env.ProcessEnvironment env)
void	doEvaluate(nextgrid.api.env.ProcessEnvironment env) Performs the actual actions needed for evaluating this process instance.
protected void	doReset() Performs specific reset actions in each subclass.
protected void	doValidate(ProcessImpl.ValidationType when) Performs any validation action needed for the process implementation.
nextgrid.api.pom.Process	findProcessById(java.net.URI id)
java.util.List<nextgrid.api.pom.Process>	getCandidates()
int	getPriority() Gets the priority (evaluation order) of this process.
nextgrid.api.pom.QueryProfile	getProfile()
nextgrid.api.pom.Process	getSelected()
void	prioritise(nextgrid.api.env.ProcessEnvironment env, java.util.PriorityQueue<nextgrid.api.pom.Process> queue)
protected void	resetChildren() Resets any child process.
void	run(ProcessContext ctx) Performs the actual enaction of a process.
void	setCandidates(java.util.Collection<nextgrid.api.pom.Process> candidates)
void	setPriority(int priority) Sets the priority (evaluation order) of this process.
void	setProfile(nextgrid.api.pom.QueryProfile profile)
void	setSelected(nextgrid.api.pom.Process selected) Sets the selected process.
java.lang.String	toString()

Methods inherited from class com.gridsystems.nextgrid.api.pom.ProcessImpl

attachListeners, enact, evaluate, evaluate, findRoot, getAttribute, getAttribute, getAttribute, getAttributes, getDescription, getId, getInput, getInputs, getInputs, getInputType, getName, getOutput, getOutputs, getOutputs, getOutputType, getParent, getState, getUsedInputNames, getUsedOutputNames, invalidate, isEvaluated, isLazy, isValidated, prioritise, putInput, putOutput, removeInput, removeOutput, reset, setAttribute, setAttribute, setDescription, setEvaluated, setId, setLazy, setName, setParent, setState, unuseInput, unuseOutput, useInput, useOutput, validate, waitForInputs

Methods inherited from class com.gridsystems.nextgrid.api.pom.PemHelper

addListener, fireDiscovererSelected, fireDiscoveryFailed, fireDiscoveryFinished, fireDiscoveryStarting, fireEvent, fireProcessEvaluated, fireProcessFailed, fireProcessFailed, fireProcessFinished, fireProcessFinished, fireProcessSelected, fireProcessStarted, removeListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface nextgrid.api.pom.Process

addListener, enact, evaluate, findRoot, getAttribute, getAttribute, getAttribute, getAttributes, getDescription, getId, getInput, getInputs, getInputType, getName, getOutput, getOutputs, getOutputType, getParent, getUsedInputNames, getUsedOutputNames, invalidate, isEvaluated, isLazy, isValidated, putInput, putOutput, removeInput, removeListener, removeOutput, reset, setAttribute, setAttribute, setDescription, setId, setLazy, setName, setParent, unuseInput, unuseOutput, useInput, useOutput, validate

Constructor Detail

AbstractProcessImpl

public AbstractProcessImpl()

Creates an instance.

AbstractProcessImpl

public AbstractProcessImpl(nextgrid.api.pom.QueryProfile profile)

Creates a new instance.

Parameters:

profile - The query profile that defines this process

Method Detail

getCandidates

public java.util.List<nextgrid.api.pom.Process> getCandidates()

Specified by:

getCandidates in interface nextgrid.api.pom.AbstractProcess

setCandidates

public void setCandidates(java.util.Collection<nextgrid.api.pom.Process> candidates)

Specified by:

setCandidates in interface nextgrid.api.pom.AbstractProcess

getSelected

public nextgrid.api.pom.Process getSelected()

Specified by:

getSelected in interface nextgrid.api.pom.AbstractProcess

setSelected

public void setSelected(nextgrid.api.pom.Process selected)

Sets the selected process.

Specified by:

setSelected in interface nextgrid.api.pom.AbstractProcess

Parameters:

selected - The new selected process

getPriority

public int getPriority()

Gets the priority (evaluation order) of this process.

Specified by:

getPriority in interface nextgrid.api.pom.AbstractProcess

Returns:

The priority

setPriority

public void setPriority(int priority)

Sets the priority (evaluation order) of this process.

Specified by:

setPriority in interface nextgrid.api.pom.AbstractProcess

Parameters:

priority - The new priority value

getProfile

public nextgrid.api.pom.QueryProfile getProfile()

Specified by:

getProfile in interface nextgrid.api.pom.AbstractProcess

setProfile

public void setProfile(nextgrid.api.pom.QueryProfile profile)

Specified by:

setProfile in interface nextgrid.api.pom.AbstractProcess

findProcessById

public nextgrid.api.pom.Process findProcessById(java.net.URI id)

Specified by:

findProcessById in interface nextgrid.api.pom.Process

doValidate

protected void doValidate(ProcessImpl.ValidationType when)
                   throws nextgrid.api.pom.ProcessException

Performs any validation action needed for the process implementation.

Specified by:

doValidate in class ProcessImpl

Parameters:

when - Specifies when this validation is being invoked

Throws:

nextgrid.api.pom.ProcessException - If the validation fails

doEvaluate

public void doEvaluate(nextgrid.api.env.ProcessEnvironment env)
                throws nextgrid.api.pom.ProcessException

Performs the actual actions needed for evaluating this process instance.

Specified by:

doEvaluate in class ProcessImpl

Parameters:

env - The process environment

Throws:

nextgrid.api.pom.ProcessException - If an error occurs

prioritise

public void prioritise(nextgrid.api.env.ProcessEnvironment env,
                       java.util.PriorityQueue<nextgrid.api.pom.Process> queue)
                throws nextgrid.api.pom.ProcessException

Specified by:

prioritise in interface nextgrid.api.pom.Process

Throws:

nextgrid.api.pom.ProcessException

discover

public void discover(nextgrid.api.env.ProcessEnvironment env)
              throws nextgrid.api.pom.ProcessException

Specified by:

discover in interface nextgrid.api.pom.Process

Throws:

nextgrid.api.pom.ProcessException

doReset

protected void doReset()

Performs specific reset actions in each subclass.

Specified by:

doReset in class ProcessImpl

resetChildren

protected void resetChildren()

Resets any child process.

Specified by:

resetChildren in class ProcessImpl

run

public void run(ProcessContext ctx)
         throws nextgrid.api.pom.ProcessException,
                java.lang.InterruptedException

Performs the actual enaction of a process.

The instance must take into account possible errors, like service unavailability, or execution errors. As long as there are more "valid" candidates for the process, errors should not be propagated to the parent, and the next candidate should be selected and enacted.

A ProcessException as a result of this call means that this process is unable to correctly finish its execution, and that the parent must do something to fix the problem.

Specified by:

run in interface Enactable

Parameters:

ctx - A process context

Throws:

nextgrid.api.pom.ProcessException - If an unrecoverable local error occurs

java.lang.InterruptedException - If the thread is interrupted

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

copy

public nextgrid.api.pom.Process copy()

Specified by:

copy in interface nextgrid.api.pom.Process

Overrides:

copy in class ProcessImpl