ostore.apps.test
Class TapestryHowto

java.lang.Object
  |
  +--ostore.apps.test.TapestryHowto

All Implemented Interfaces:

EventHandlerIF

public class TapestryHowto

extends Object

implements EventHandlerIF

A simple example of how to write your own DD client and message types. The example is as follows. We bring up two machines, a sender and a receiver. The sender sends a Ping message to the receiver, which the receiver acknoledges with a Pong. This happens a number of times, and then the test exits. It's simple, but it covers most of the things you need to know to do more complicated things. Please just read the source, it's well commented.

First off, this class is going to be a SEDA/Sandstorm stage, so it has to inherit from EventHandlerIF.

Version:

$Id: TapestryHowto.java,v 1.15 2004/05/13 19:42:42 hweather Exp $

Author:

Sean C. Rhea

Nested Class Summary

static class	TapestryHowto.Ping One of two DD messages used in this test.
static class	TapestryHowto.Pong This class is identical in all by type from the Ping class above, so I'm not going to comment it further.

Constructor Summary

TapestryHowto()

Method Summary

void	destroy() Sandstorm calls this function when it unloads your stage, which to my knowledge, it never does.
void	handleEvent(QueueElementIF item) This is the function that will be called when a stage dispatches a message that we've subscribed to.
void	handleEvents(QueueElementIF[] items) If Sandstorm has more than one event waiting for this stage, it will call this function instead of handleEvent.
void	init(ConfigDataIF config) Initializes the stage once Sandstorm is up and running.

Methods inherited from class java.lang.Object

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

Constructor Detail

TapestryHowto

public TapestryHowto()

Method Detail

init

public void init(ConfigDataIF config)
          throws Exception

Initializes the stage once Sandstorm is up and running.

You'll notice that most stages won't have constructors. The reason is that all initialization can take place here, where you have the information from your stage's config file to help you. I'll detail the important things you want to do in this function below.

Specified by:

init in interface EventHandlerIF

Exception

handleEvent

public void handleEvent(QueueElementIF item)
                 throws EventHandlerException

This is the function that will be called when a stage dispatches a message that we've subscribed to.

Specified by:

handleEvent in interface EventHandlerIF

EventHandlerException

handleEvents

public void handleEvents(QueueElementIF[] items)
                  throws EventHandlerException

If Sandstorm has more than one event waiting for this stage, it will call this function instead of handleEvent. If you wanted to get fancy, you could do something like sorting these events based on priority before handling them.

Specified by:

handleEvents in interface EventHandlerIF

EventHandlerException

destroy

public void destroy()
             throws Exception

Sandstorm calls this function when it unloads your stage, which to my knowledge, it never does. I think it's safe to ignore it completely.

Specified by:

destroy in interface EventHandlerIF

Exception