org.licas.server.esb

Class PublishSubscribe

java.lang.Object

org.licas.server.esb.PublishSubscribe

All Implemented Interfaces:

PublishSubscribeDef

public class PublishSubscribe
extends java.lang.Object
implements PublishSubscribeDef

This class records requests for a service from clients and responds with appropriate replies when a service registers it can carry out the request. Requests are submitted in the form of a MethodInfo description and a KeywordInfo list of keywords. The method description must include a client URI or it will be rejected. This uniquely defines the service or client. The keyword lists may not overlap for any one client or service. They may not share any keywords, but the topic names can be shared.

Author:

Kieran Greer

Constructor Summary

Constructors

Constructor and Description
PublishSubscribe() Create a new instance of PublishSubscribe

Method Summary

Modifier and Type	Method and Description
protected void	addToRegister(java.lang.String address, WorkInfo workInfo, java.util.HashMap<java.lang.String,java.util.ArrayList<WorkInfo>> register) Add the request to do work.
protected WorkInfo	getWorkInfo(java.lang.String address, KeywordInfo keyInfo, java.util.HashMap<java.lang.String,java.util.ArrayList<WorkInfo>> register) If a work description is already saved under the service address and keyword list then return it, otherwise return null.
static MethodInfo	methodForPublish(org.licas_xml.abs.Element serverUri, java.lang.String serverPassword, KeywordInfo keywords, MethodInfo replyMethod, PasswordHandler pHandler) Create and return the full method list for publishing a service's information.
static MethodInfo	methodForSubscribe(org.licas_xml.abs.Element serverUri, java.lang.String serverPassword, KeywordInfo keywords, MethodInfo replyMethod, PasswordHandler pHandler) Create and return the full method list for subscribing to a service's information.
boolean	publish(WorkInfo workInfo) Publish to do work.
protected void	removeFromRegister(java.lang.String address, KeywordInfo keyInfo, java.util.HashMap<java.lang.String,java.util.ArrayList<WorkInfo>> register) Add the request to do work.
boolean	subscribe(WorkInfo workInfo) Subscribe for a service.
void	unpublish(KeywordInfo keyInfo, org.licas_xml.abs.Element clientURI) Un-publish to do work.
void	unsubscribe(KeywordInfo keyInfo, org.licas_xml.abs.Element clientURI) Un-subscribe for a service.

Methods inherited from class java.lang.Object

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

Constructor Detail

PublishSubscribe

public PublishSubscribe()

Create a new instance of PublishSubscribe

Method Detail

subscribe

public boolean subscribe(WorkInfo workInfo)
                  throws java.lang.Exception

Subscribe for a service. Each time a service publishes a matching work description any subscriber is sent the WorkInfo details. An immediate check is done to determine if matching work is available.

Specified by:

subscribe in interface PublishSubscribeDef

Parameters:

workInfo - new client details. It must include the keyword list and the method to reply with.

1. A list of descriptive keywords and topic to match with.
2. Details of the client method to reply with if a service work matches with the keywords request.

The details method must comply with some specific formatting as follows:

1. It must include the client URI, as this is what identifies the request. If getClientURI() is empty, then the request is ignored.
2. It must contain a parameter list of size 1, that is either an Object or a WorkInfo object, as that is what will be sent as a reply.
3. The return type must be void (asynchronous call).

Returns:

true if added as a new request, or false if service request is already registered, via keyword or topic overlap, for example.

Throws:

java.lang.Exception - any error.

unsubscribe

public void unsubscribe(KeywordInfo keyInfo,
                        org.licas_xml.abs.Element clientURI)
                 throws java.lang.Exception

Un-subscribe for a service.

Specified by:

unsubscribe in interface PublishSubscribeDef

Parameters:

keyInfo - list of descriptive keywords to uniquely identify the service.

clientURI - the client URI defines the request client.

Throws:

java.lang.Exception - any error.

publish

public boolean publish(WorkInfo workInfo)
                throws java.lang.Exception

Publish to do work. This triggers a message to all subscribed services each time and any publishing service may publish the same work request any number of times. Only the first published request is saved however and then then sent out each time.

Specified by:

publish in interface PublishSubscribeDef

Parameters:

workInfo - full work details, including an optional contract. The method description must include the client URI as this is what identifies the request. If getClientURI() is empty, then the request is ignored.

Returns:

true if added as a new request, or false if work request is already registered, via keyword or topic overlap, for example.

Throws:

java.lang.Exception - any error.

unpublish

public void unpublish(KeywordInfo keyInfo,
                      org.licas_xml.abs.Element clientURI)
               throws java.lang.Exception

Un-publish to do work.

Specified by:

unpublish in interface PublishSubscribeDef

Parameters:

keyInfo - list of descriptive keywords to uniquely identify the work.

clientURI - the client URI defines the request service.

Throws:

java.lang.Exception - any error.

addToRegister

protected void addToRegister(java.lang.String address,
                             WorkInfo workInfo,
                             java.util.HashMap<java.lang.String,java.util.ArrayList<WorkInfo>> register)

Add the request to do work.

Parameters:

address - unique address for the client.

workInfo - the work request.

register - the register to add to.

removeFromRegister

protected void removeFromRegister(java.lang.String address,
                                  KeywordInfo keyInfo,
                                  java.util.HashMap<java.lang.String,java.util.ArrayList<WorkInfo>> register)
                           throws java.lang.Exception

Add the request to do work.

Parameters:

address - unique address for the client.

keyInfo - keywords list to identify the work description.

register - the register to add to.

Throws:

java.lang.Exception - any error.

getWorkInfo

protected WorkInfo getWorkInfo(java.lang.String address,
                               KeywordInfo keyInfo,
                               java.util.HashMap<java.lang.String,java.util.ArrayList<WorkInfo>> register)
                        throws java.lang.Exception

If a work description is already saved under the service address and keyword list then return it, otherwise return null.

Parameters:

address - unique address for the client/service.

keyInfo - list of keywords. None must be present in a currently saved work request by the same service.

register - the register to check.

Returns:

true if OK.

Throws:

java.lang.Exception - any error.

methodForPublish

public static MethodInfo methodForPublish(org.licas_xml.abs.Element serverUri,
                                          java.lang.String serverPassword,
                                          KeywordInfo keywords,
                                          MethodInfo replyMethod,
                                          PasswordHandler pHandler)
                                   throws java.lang.Exception

Create and return the full method list for publishing a service's information.

Parameters:

serverUri - address for the server to call.

serverPassword - the server password.

keywords - list of keywords to represent the published information.

replyMethod - callback method by the server after publshing.

pHandler - the service password handler.

Returns:

a MethodInfo object to make a server publish invocation with.

Throws:

java.lang.Exception - any error.

methodForSubscribe

public static MethodInfo methodForSubscribe(org.licas_xml.abs.Element serverUri,
                                            java.lang.String serverPassword,
                                            KeywordInfo keywords,
                                            MethodInfo replyMethod,
                                            PasswordHandler pHandler)
                                     throws java.lang.Exception

Create and return the full method list for subscribing to a service's information.

Parameters:

serverUri - address for the server to call.

serverPassword - the server password.

keywords - list of keywords to represent the published information.

replyMethod - callback method by the server, to send the published data to.

pHandler - the service password handler.

Returns:

a MethodInfo object to make a server subscribe invocation with.

Throws:

java.lang.Exception - any error.