com.idimiddleware.objectq

Class Agent

java.lang.Object

com.idimiddleware.objectq.Agent

public abstract class Agent
extends java.lang.Object

The Agent class is designed to provide operations on distributed objects. The Agent may perform all or part of the operations itself, use a Manager object to access other distributed objects, or implement any other application specific operations or communications to service the request. When the Agent has completed the request, it will send one or more responses back to the manager which made the request. The Agent class is an abstract base class, intended to act as the parent of application specific Agent classes. Each application specific Agent class will provide distributed object services on one or more classes of objects. However, all Agent classes perform these same basic operations:

• Register service with the Dispatcher.
• Register service with the TransportManager.
• Use the Message object to extract data from a request message or construct a response message.
• Use the Envelope to package messages and extract messages.
• Use a Transport object to send responses or forward messages.
• Use a Manager if access is needed to a distributed object not managed by the agent.
• If providing subscription service, use an EventDiscriminator object to store subscription information and to determine if an event matches a subscription.

Each Agent must provide a requestHandler function to be called by the Dispatcher when a service request is received. When the Dispatcher executes this function, it will mark the Agent object as busy. Since each Agent object works on only one service request at a time, when the Agent object is finished with a service request, it must notify the Dispatcher that it is available. A server process may have more than one Agent object providing the same service.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	service

Constructor Summary

Constructors

Constructor and Description
Agent() Default constructor - the service must be set separately.
Agent(java.lang.String service) Constructor specifying the service for which te Agent is responsible.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getService() Get the service for which the Agent is responsible.
protected abstract void	notifyComplete(Manager manager) This method is invoked by a Manager when a request is fully completed.
protected abstract void	notifyPartial(Manager manager) This method is invoked by a Manager when a request is partially complete.
protected abstract void	requestHandler(Envelope envelope) This method will be invoked by the Dispatcher when a request is received.
void	setService(java.lang.String service) Set the service for which the Agent is responsible.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

service

protected java.lang.String service

Constructor Detail

Agent

public Agent()

Default constructor - the service must be set separately.

Agent

public Agent(java.lang.String service)

Constructor specifying the service for which te Agent is responsible.

Parameters:

service - The service name.

Method Detail

getService

public java.lang.String getService()

Get the service for which the Agent is responsible.

Returns:

The service name.

notifyComplete

protected abstract void notifyComplete(Manager manager)

This method is invoked by a Manager when a request is fully completed. It only needs to be provided for hybrid Agent objects, that is Agent objects which instantiate a Manager object to request data from another service provider and operate asynchronously.

Parameters:

manager - The invoking manager.

notifyPartial

protected abstract void notifyPartial(Manager manager)

This method is invoked by a Manager when a request is partially complete. It only needs to be provided for hybrid Agent objects, that is Agent objects which instantiate a Manager object to request data from another service provider and operate asynchronously.

Parameters:

manager - The invoking manager.

requestHandler

protected abstract void requestHandler(Envelope envelope)
                                throws EnvelopeOverflowException,
                                       VendorTransportException

This method will be invoked by the Dispatcher when a request is received.

Parameters:

envelope - Contains the request.

Throws:

EnvelopeOverflowException

VendorTransportException

setService

public void setService(java.lang.String service)

Set the service for which the Agent is responsible.

Parameters:

service - The service name.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object