uk.org.ogsadai.activity
Class ActivityCreator

java.lang.Object
  |
  +--uk.org.ogsadai.activity.ActivityCreator

class ActivityCreator

extends java.lang.Object

An ActivityCreator knows how to create and initialise one type of Activity implementation.

When an ActivityCreator creates an Activity, the following steps are performed:

• Activity implementation object constructed. This object is an instance of the class specfied in the configuration details.
• Activity properties passed into the activity object, if applicable. Note that many activities do not use activity properties.
• Activity-specific configuration object is passed into the activity object, if applicable. Note that many activities do not use activity configuration objects.

For the sake of optimisation the activity properties and configuration objects, where applicable, are only created once and then passed into each Activity that is created.

Author:

The OGSA-DAI Project Team

Field Summary

private static java.lang.String	COPYRIGHT_NOTICE Copyright statement
private static DAILogger	LOG Logger object for logging in this class
private java.lang.String	mClass Implementation class for the Activity
private org.w3c.dom.Document	mConfigDoc Activity configuration document, if applicable, otherwise null
private ActivityConfiguration	mConfiguration Activity configuration object, if applicable, otherwise null
private java.lang.String	mName Name of the activity that this ActivityCreator creates
private java.util.Properties	mProperties The activity properties, if applicable, otherwise null.
private org.w3c.dom.Document	mSchemaDoc Activity schema document.

Constructor Summary

(package private)

ActivityCreator(ActivityConfig activityConfig) Constructs an ActivityCreator that can create the Activity described by the specified Element.

Method Summary

Activity	createActivity(org.w3c.dom.Element element) Creates an Activity instance.
java.lang.String	getName() Returns the name of the activity that this ActivityCreator can create.
org.w3c.dom.Document	getSchema() Returns the schema Document for the activity.
private void	initialiseActivityConfiguration(Activity activity, org.w3c.dom.Document configurationDoc) Creates an activity configuration object, if it hasn't already been created, then passes it into the new activity.

Methods inherited from class java.lang.Object

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

Field Detail

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

Copyright statement

See Also:

Constant Field Values

LOG

private static final DAILogger LOG

Logger object for logging in this class

mName

private final java.lang.String mName

Name of the activity that this ActivityCreator creates

mClass

private final java.lang.String mClass

Implementation class for the Activity

mSchemaDoc

private final org.w3c.dom.Document mSchemaDoc

Activity schema document.

mConfigDoc

private final org.w3c.dom.Document mConfigDoc

Activity configuration document, if applicable, otherwise null

mConfiguration

private ActivityConfiguration mConfiguration

Activity configuration object, if applicable, otherwise null

mProperties

private final java.util.Properties mProperties

The activity properties, if applicable, otherwise null.

Constructor Detail

ActivityCreator

ActivityCreator(ActivityConfig activityConfig)

Constructs an ActivityCreator that can create the Activity described by the specified Element.

Parameters:

activityConfig - Configuration details of an activity - its name, implementation classe and configuration.

Throws:

java.lang.IllegalArgumentException - If activityConfig is null.

Method Detail

createActivity

public Activity createActivity(org.w3c.dom.Element element)
                        throws ActivitySpecificationException,
                               ActivityCreationException

Creates an Activity instance.

Parameters:

element - Element from a perform document containing a specific activity.

Returns:

Activity.

Throws:

ActivitySpecificationException - If a client mistake prevents the activity from being constructed successfully. This may be raised in either of the following circumstances:

• the activity is unsupported by this factory
.
• a required element or attribute has been omitted from an activity element in a perform document

ActivityCreationException - If there is some problem that prevents an activity being created. This is typically caused by a configuration or programming error.

initialiseActivityConfiguration

private void initialiseActivityConfiguration(Activity activity,
                                             org.w3c.dom.Document configurationDoc)
                                      throws ActivityConfigurationException

Creates an activity configuration object, if it hasn't already been created, then passes it into the new activity. Note that the individual activity configuration file is not schema-validated.

Parameters:

activity - activity to pass the configuration to

configurationDoc - XML document containing the activity configuration

Throws:

ActivityConfigurationException - If there is a problem initialising the ActivityConfiguration. object

getName

public final java.lang.String getName()

Returns the name of the activity that this ActivityCreator can create. This name corresponds to the name of the element as used in a perform document for this activity, not the name of the implementation class.

Returns:

the activity name as a String

getSchema

public org.w3c.dom.Document getSchema()

Returns the schema Document for the activity.

Returns:

a Document containing XML Schema.