com.jboss.jbossnetwork.product.jbpm.handlers

Class BaseHandler

java.lang.Object

com.jboss.jbossnetwork.product.jbpm.handlers.BaseHandler

All Implemented Interfaces:

Serializable, org.jbpm.graph.def.ActionHandler

Direct Known Subclasses:

BackupAndReplaceFileActionHandler, CompareDigestActionHandler, ControlActionHandler, JONServerDownloadActionHandler, NotificationActionHandler, UnzipActionHandler

public abstract class BaseHandler
extends Object
implements org.jbpm.graph.def.ActionHandler

Base class for all of our JBPM handlers, providing some basic functionality for transitioning between steps.

Author:

Jason Dobies

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.commons.logging.Log	logger Logger, keyed to the subclass.
protected static String	MESSAGE_NO_CHANGES Standard message to describe that no changes were made by the currently executing step.
protected static String	TRANSITION_ERROR Describes an error in a step, preventing transitioning.
protected static String	TRANSITION_SUCCESS Describes a successful transition between steps.

Constructor Summary

Constructors

Constructor and Description
BaseHandler()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	checkProperties() Ensures the property values that were set in substituteVariables(org.jbpm.graph.exe.ExecutionContext) are valid.
protected void	complete(org.jbpm.graph.exe.ExecutionContext executionContext, String message) Called by a handler at the end of its processing to indicate a step was completed successfully and transitions to the next step in the workflow.
protected void	error(org.jbpm.graph.exe.ExecutionContext executionContext, Throwable throwable, String additionalMessage, String leavingTransition) Called by a handler at the end of its processing to indicate an error occurred in the execution of a given step and closes out the step.
void	execute(org.jbpm.graph.exe.ExecutionContext executionContext)
abstract String	getDescription() Returns a user readable description of what the step in the workflow entails.
protected void	notRun(org.jbpm.graph.exe.ExecutionContext executionContext, String message) Called by a handler at the end of its processing to indicate a step was skipped and transitions to the next step in the workflow.
abstract void	run(org.jbpm.graph.exe.ExecutionContext executionContext) Tells the handle implementation to actually perform the step indicated.
void	setPropertyDefaults() Sets the default values for properties used by the handler implementation.
protected void	skip(org.jbpm.graph.exe.ExecutionContext executionContext, ActionHandlerException exception, String additionalMessage, String leavingTransition) Called by a handler at the end of its processing to indicate a step in the workflow has been skipped and transitions to the next step in the workflow.
protected String	substituteVariable(String expression, org.jbpm.graph.exe.ExecutionContext executionContext) Substitutes in values found in the workflow (execution context) for the specified expression.
void	substituteVariables(org.jbpm.graph.exe.ExecutionContext executionContext) Requests the action handler substitute into its node any variables necessary, taking the values for these from the provided execution context.

Methods inherited from class java.lang.Object

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

Field Detail

TRANSITION_SUCCESS

protected static final String TRANSITION_SUCCESS

Describes a successful transition between steps.

See Also:

Constant Field Values

TRANSITION_ERROR

protected static final String TRANSITION_ERROR

Describes an error in a step, preventing transitioning.

See Also:

Constant Field Values

MESSAGE_NO_CHANGES

protected static final String MESSAGE_NO_CHANGES

Standard message to describe that no changes were made by the currently executing step.

See Also:

Constant Field Values

logger

protected final org.apache.commons.logging.Log logger

Logger, keyed to the subclass.

Constructor Detail

BaseHandler

public BaseHandler()

Method Detail

getDescription

public abstract String getDescription()

Returns a user readable description of what the step in the workflow entails.

Returns:

should not be null

run

public abstract void run(org.jbpm.graph.exe.ExecutionContext executionContext)

Tells the handle implementation to actually perform the step indicated.

Parameters:

executionContext - cannot be null

setPropertyDefaults

public void setPropertyDefaults()

Sets the default values for properties used by the handler implementation. This may optionally be overridden by action handler implementations if necessary.

substituteVariables

public void substituteVariables(org.jbpm.graph.exe.ExecutionContext executionContext)
                         throws ActionHandlerException

Requests the action handler substitute into its node any variables necessary, taking the values for these from the provided execution context. This may optionally be overridden by action handler implementations if necessary.

Parameters:

executionContext - JBPM execution context from which the property values should be extracted

Throws:

ActionHandlerException - if there is an error extraction or substituting the variables

checkProperties

protected void checkProperties()
                        throws ActionHandlerException

Ensures the property values that were set in substituteVariables(org.jbpm.graph.exe.ExecutionContext) are valid. This may optionally be overridden by action handler implementations if necessary.

Throws:

ActionHandlerException - if any of the properties are invalid

execute

public void execute(org.jbpm.graph.exe.ExecutionContext executionContext)
             throws Exception

Specified by:

execute in interface org.jbpm.graph.def.ActionHandler

Throws:

Exception

error

protected void error(org.jbpm.graph.exe.ExecutionContext executionContext,
         Throwable throwable,
         String additionalMessage,
         String leavingTransition)

Called by a handler at the end of its processing to indicate an error occurred in the execution of a given step and closes out the step.

Parameters:

executionContext - context in which the step was executing

throwable - exception that occurred to trigger this call to error

additionalMessage - additional details to report on the step

leavingTransition - ?

complete

protected void complete(org.jbpm.graph.exe.ExecutionContext executionContext,
            String message)

Called by a handler at the end of its processing to indicate a step was completed successfully and transitions to the next step in the workflow.

Parameters:

executionContext - context in which the step was executing

message - additional details on the step

skip

protected void skip(org.jbpm.graph.exe.ExecutionContext executionContext,
        ActionHandlerException exception,
        String additionalMessage,
        String leavingTransition)

Called by a handler at the end of its processing to indicate a step in the workflow has been skipped and transitions to the next step in the workflow.

Parameters:

executionContext - context in which the step was executing

exception - exception that occurred to trigger this call to error

additionalMessage - additional details to report on the step

leavingTransition - ?

notRun

protected void notRun(org.jbpm.graph.exe.ExecutionContext executionContext,
          String message)

Called by a handler at the end of its processing to indicate a step was skipped and transitions to the next step in the workflow.

Parameters:

executionContext - context in which the step was executing

message - additional details on the step

substituteVariable

protected String substituteVariable(String expression,
                        org.jbpm.graph.exe.ExecutionContext executionContext)
                             throws ActionHandlerException

Substitutes in values found in the workflow (execution context) for the specified expression.

Parameters:

expression - expression into which to substitute values from the workflow

executionContext - context describing the workflow

Returns:

expression with the proper values substituted in; null if the expression is null

Throws:

ActionHandlerException - if there is an error during the substitution