/*
* Copyright (C) 2010 Stanford University
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package edu.stanford.junction.api.messaging;
import java.util.List;
import org.json.JSONObject;
public abstract class MessageHandler {
/**
* Stream-selecting filters;
* These filters allow Junction to route messages
* using the network's capabilities.
*
* If we are sending to a fixed actor, try and establish a direct connection.
* If we are sending to a fixed role or multiple actors, we can
* potentially multicast.
*
* These methods should return static results (list of actors does not change
* over the lifetime of the handler)
*/
public List<String> supportedRoles() { return null; } // default is to not filter on roles.
public List<String> supportedActors() { return null; } // default is to not filter on actors.
public List<String> supportedChannels() { return null; } // default is to not filter on channel.
/**
* Message-level filter
*
* These filters may be convenient for the end-user.
* May be useful to support RPC, for example
*
*/
public boolean supportsMessage(JSONObject message) { return true; }
// TODO: have a dynamic filter and a static one.
// the static one defines a message template, and this template can be
// shared (like an XML XSD document)
/**
* Message handling
*/
public abstract void onMessageReceived(MessageHeader header, JSONObject message);
/**
* How to add response capabilities?
* This should be bridged with Junction.sendMessageToXXX
* We might need a MessageTarget or something.
*/
// getMessageRecipients;
// getMessageSender;
// replyToSender;
// replyAll
}