/*****************************************************************
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.bookTrading;
import jade.core.Agent;
import jade.core.AID;
import jade.core.behaviours.*;
import jade.lang.acl.ACLMessage;
import jade.lang.acl.MessageTemplate;
import jade.domain.DFService;
import jade.domain.FIPAException;
import jade.domain.FIPAAgentManagement.DFAgentDescription;
import jade.domain.FIPAAgentManagement.ServiceDescription;
public class BookBuyerAgent extends Agent {
// The title of the book to buy
private String targetBookTitle;
// The list of known seller agents
private AID[] sellerAgents;
// Put agent initializations here
protected void setup() {
// Printout a welcome message
System.out.println("Hallo! Buyer-agent "+getAID().getName()+" is ready.");
// Get the title of the book to buy as a start-up argument
Object[] args = getArguments();
if (args != null && args.length > 0) {
targetBookTitle = (String) args[0];
System.out.println("Target book is "+targetBookTitle);
// Add a TickerBehaviour that schedules a request to seller agents every minute
addBehaviour(new TickerBehaviour(this, 60000) {
protected void onTick() {
System.out.println("Trying to buy "+targetBookTitle);
// Update the list of seller agents
DFAgentDescription template = new DFAgentDescription();
ServiceDescription sd = new ServiceDescription();
sd.setType("book-selling");
template.addServices(sd);
try {
DFAgentDescription[] result = DFService.search(myAgent, template);
System.out.println("Found the following seller agents:");
sellerAgents = new AID[result.length];
for (int i = 0; i < result.length; ++i) {
sellerAgents[i] = result[i].getName();
System.out.println(sellerAgents[i].getName());
}
}
catch (FIPAException fe) {
fe.printStackTrace();
}
// Perform the request
myAgent.addBehaviour(new RequestPerformer());
}
} );
}
else {
// Make the agent terminate
System.out.println("No target book title specified");
doDelete();
}
}
// Put agent clean-up operations here
protected void takeDown() {
// Printout a dismissal message
System.out.println("Buyer-agent "+getAID().getName()+" terminating.");
}
/**
Inner class RequestPerformer.
This is the behaviour used by Book-buyer agents to request seller
agents the target book.
*/
private class RequestPerformer extends Behaviour {
private AID bestSeller; // The agent who provides the best offer
private int bestPrice; // The best offered price
private int repliesCnt = 0; // The counter of replies from seller agents
private MessageTemplate mt; // The template to receive replies
private int step = 0;
public void action() {
switch (step) {
case 0:
// Send the cfp to all sellers
ACLMessage cfp = new ACLMessage(ACLMessage.CFP);
for (int i = 0; i < sellerAgents.length; ++i) {
cfp.addReceiver(sellerAgents[i]);
}
cfp.setContent(targetBookTitle);
cfp.setConversationId("book-trade");
cfp.setReplyWith("cfp"+System.currentTimeMillis()); // Unique value
myAgent.send(cfp);
// Prepare the template to get proposals
mt = MessageTemplate.and(MessageTemplate.MatchConversationId("book-trade"),
MessageTemplate.MatchInReplyTo(cfp.getReplyWith()));
step = 1;
break;
case 1:
// Receive all proposals/refusals from seller agents
ACLMessage reply = myAgent.receive(mt);
if (reply != null) {
// Reply received
if (reply.getPerformative() == ACLMessage.PROPOSE) {
// This is an offer
int price = Integer.parseInt(reply.getContent());
if (bestSeller == null || price < bestPrice) {
// This is the best offer at present
bestPrice = price;
bestSeller = reply.getSender();
}
}
repliesCnt++;
if (repliesCnt >= sellerAgents.length) {
// We received all replies
step = 2;
}
}
else {
block();
}
break;
case 2:
// Send the purchase order to the seller that provided the best offer
ACLMessage order = new ACLMessage(ACLMessage.ACCEPT_PROPOSAL);
order.addReceiver(bestSeller);
order.setContent(targetBookTitle);
order.setConversationId("book-trade");
order.setReplyWith("order"+System.currentTimeMillis());
myAgent.send(order);
// Prepare the template to get the purchase order reply
mt = MessageTemplate.and(MessageTemplate.MatchConversationId("book-trade"),
MessageTemplate.MatchInReplyTo(order.getReplyWith()));
step = 3;
break;
case 3:
// Receive the purchase order reply
reply = myAgent.receive(mt);
if (reply != null) {
// Purchase order reply received
if (reply.getPerformative() == ACLMessage.INFORM) {
// Purchase successful. We can terminate
System.out.println(targetBookTitle+" successfully purchased from agent "+reply.getSender().getName());
System.out.println("Price = "+bestPrice);
myAgent.doDelete();
}
else {
System.out.println("Attempt failed: requested book already sold.");
}
step = 4;
}
else {
block();
}
break;
}
}
public boolean done() {
if (step == 2 && bestSeller == null) {
System.out.println("Attempt failed: "+targetBookTitle+" not available for sale");
}
return ((step == 2 && bestSeller == null) || step == 4);
}
} // End of inner class RequestPerformer
}