contractnetresponderagent.java

JADE(JAVA Agent开发框架)是一个完全由JAVA语言开发的软件,它简化了多Agent系统的实现。

/**
 * ***************************************************************
 * JADE - Java Agent DEvelopment Framework is a framework to develop
 * multi-agent systems in compliance with the FIPA specifications.
 * Copyright (C) 2000 CSELT S.p.A.
 * 
 * GNU Lesser General Public License
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation,
 * version 2.1 of the License.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 * **************************************************************
 */
package examples.protocols;

import jade.core.Agent;
import jade.core.AID;
import jade.lang.acl.ACLMessage;
import jade.lang.acl.MessageTemplate;
import jade.proto.ContractNetResponder;
import jade.domain.FIPANames;
import jade.domain.FIPAAgentManagement.NotUnderstoodException;
import jade.domain.FIPAAgentManagement.RefuseException;
import jade.domain.FIPAAgentManagement.FailureException;

/**
   This example shows how to implement the responder role in 
   a FIPA-contract-net interaction protocol. In this case in particular 
   we use a <code>ContractNetResponder</code>  
   to participate into a negotiation where an initiator needs to assign
   a task to an agent among a set of candidates.
   @author Giovanni Caire - TILAB
 */
public class ContractNetResponderAgent extends Agent {
	
  protected void setup() {
  	System.out.println("Agent "+getLocalName()+" waiting for CFP...");
  	MessageTemplate template = MessageTemplate.and(
  		MessageTemplate.MatchProtocol(FIPANames.InteractionProtocol.FIPA_CONTRACT_NET),
  		MessageTemplate.MatchPerformative(ACLMessage.CFP) );
  		
		addBehaviour(new ContractNetResponder(this, template) {
			protected ACLMessage prepareResponse(ACLMessage cfp) throws NotUnderstoodException, RefuseException {
				System.out.println("Agent "+getLocalName()+": CFP received from "+cfp.getSender().getName()+". Action is "+cfp.getContent());
				int proposal = evaluateAction();
				if (proposal > 2) {
					// We provide a proposal
					System.out.println("Agent "+getLocalName()+": Proposing "+proposal);
					ACLMessage propose = cfp.createReply();
					propose.setPerformative(ACLMessage.PROPOSE);
					propose.setContent(String.valueOf(proposal));
					return propose;
				}
				else {
					// We refuse to provide a proposal
					System.out.println("Agent "+getLocalName()+": Refuse");
					throw new RefuseException("evaluation-failed");
				}
			}
			
			protected ACLMessage prepareResultNotification(ACLMessage cfp, ACLMessage propose,ACLMessage accept) throws FailureException {
				System.out.println("Agent "+getLocalName()+": Proposal accepted");
				if (performAction()) {
					System.out.println("Agent "+getLocalName()+": Action successfully performed");
					ACLMessage inform = accept.createReply();
					inform.setPerformative(ACLMessage.INFORM);
					return inform;
				}
				else {
					System.out.println("Agent "+getLocalName()+": Action execution failed");
					throw new FailureException("unexpected-error");
				}	
			}
			
			protected void handleRejectProposal(ACLMessage cfp, ACLMessage propose, ACLMessage reject) {
				System.out.println("Agent "+getLocalName()+": Proposal rejected");
			}
		} );
  }
  
  private int evaluateAction() {
  	// Simulate an evaluation by generating a random number
  	return (int) (Math.random() * 10);
  }
  
  private boolean performAction() {
  	// Simulate action execution by generating a random number
  	return (Math.random() > 0.2);
  }
}