bookselleragent.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.bookTrading;

import jade.core.Agent;
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;

import java.util.*;

public class BookSellerAgent extends Agent {
  // The catalogue of books for sale (maps the title of a book to its price)
  private Hashtable catalogue;
  // The GUI by means of which the user can add books in the catalogue
  private BookSellerGui myGui;

  // Put agent initializations here
  protected void setup() {
    // Create the catalogue
    catalogue = new Hashtable();

    // Create and show the GUI 
    myGui = new BookSellerGui(this);
    myGui.show();

    // Register the book-selling service in the yellow pages
    DFAgentDescription dfd = new DFAgentDescription();
    dfd.setName(getAID());
    ServiceDescription sd = new ServiceDescription();
    sd.setType("book-selling");
    sd.setName("JADE-book-trading");
    dfd.addServices(sd);
    try {
      DFService.register(this, dfd);
    }
    catch (FIPAException fe) {
      fe.printStackTrace();
    }
    
    // Add the behaviour serving queries from buyer agents
    addBehaviour(new OfferRequestsServer());

    // Add the behaviour serving purchase orders from buyer agents
    addBehaviour(new PurchaseOrdersServer());
  }

  // Put agent clean-up operations here
  protected void takeDown() {
    // Deregister from the yellow pages
    try {
      DFService.deregister(this);
    }
    catch (FIPAException fe) {
      fe.printStackTrace();
    }
  	// Close the GUI
  	myGui.dispose();
    // Printout a dismissal message
    System.out.println("Seller-agent "+getAID().getName()+" terminating.");
  }

  /**
     This is invoked by the GUI when the user adds a new book for sale
   */
  public void updateCatalogue(final String title, final int price) {
    addBehaviour(new OneShotBehaviour() {
      public void action() {
        catalogue.put(title, new Integer(price));
        System.out.println(title+" inserted into catalogue. Price = "+price);
      }
    } );
  }
  
	/**
	   Inner class OfferRequestsServer.
	   This is the behaviour used by Book-seller agents to serve incoming requests 
	   for offer from buyer agents.
	   If the requested book is in the local catalogue the seller agent replies 
	   with a PROPOSE message specifying the price. Otherwise a REFUSE message is
	   sent back.
	 */
	private class OfferRequestsServer extends CyclicBehaviour {
	  public void action() {
		  MessageTemplate mt = MessageTemplate.MatchPerformative(ACLMessage.CFP);
		  ACLMessage msg = myAgent.receive(mt);
	    if (msg != null) {
	      // CFP Message received. Process it
	      String title = msg.getContent();
	      ACLMessage reply = msg.createReply();
	
	      Integer price = (Integer) catalogue.get(title);
	      if (price != null) {
	        // The requested book is available for sale. Reply with the price
	        reply.setPerformative(ACLMessage.PROPOSE);
	        reply.setContent(String.valueOf(price.intValue()));
	      }
	      else {
	        // The requested book is NOT available for sale.
	        reply.setPerformative(ACLMessage.REFUSE);
	        reply.setContent("not-available");
	      }
	      myAgent.send(reply);
	    }
		  else {
		    block();
		  }
	  }
	}  // End of inner class OfferRequestsServer
	
	/**
	   Inner class PurchaseOrdersServer.
	   This is the behaviour used by Book-seller agents to serve incoming 
	   offer acceptances (i.e. purchase orders) from buyer agents.
	   The seller agent removes the purchased book from its catalogue 
	   and replies with an INFORM message to notify the buyer that the
	   purchase has been sucesfully completed.
	 */
	private class PurchaseOrdersServer extends CyclicBehaviour {
	  public void action() {
		  MessageTemplate mt = MessageTemplate.MatchPerformative(ACLMessage.ACCEPT_PROPOSAL);
		  ACLMessage msg = myAgent.receive(mt);
	    if (msg != null) {
	      // ACCEPT_PROPOSAL Message received. Process it
	      String title = msg.getContent();
	      ACLMessage reply = msg.createReply();
	      
	      Integer price = (Integer) catalogue.remove(title);
	      if (price != null) {
	        reply.setPerformative(ACLMessage.INFORM);
	        System.out.println(title+" sold to agent "+msg.getSender().getName());
	      }
	      else {
	        // The requested book has been sold to another buyer in the meanwhile .
	        reply.setPerformative(ACLMessage.FAILURE);
	        reply.setContent("not-available");
	      }
	      myAgent.send(reply);
	    }
		  else {
		    block();
		  }
	  }
	}  // End of inner class OfferRequestsServer
}