Package jade.proto

Class ContractNetResponder

  • All Implemented Interfaces:
    Serializable, Serializable
    public class ContractNetResponder
extends SSContractNetResponder
    Behaviour class for fipa-contract-net Responder role. This behaviour implements the fipa-contract-net interaction protocol from the point of view of a responder to a call for proposal (cfp) message.

    The API of this class is similar and homogeneous to the AchieveREResponder.

    Read also the introduction to ContractNetInitiator for a description of the protocol.

    When a message arrives that matches the message template passed to the constructor, the callback method prepareResponse is executed that must return the wished response, for instance the PROPOSE reply message. Any other type of returned communicative act is sent and then closes the protocol.

    Then, if the initiator accepted the proposal, i.e. if an ACCEPT-PROPOSAL message was received, the callback method prepareResultNotification would be executed that must return the message with the result notification, i.e. INFORM or FAILURE.
    In alternative, if the initiator rejected the proposal, i.e. if an REJECT-PROPOSAL message was received, the callback method handleRejectProposal would be executed and the protocol terminated.

    If a message were received, with the same value of this conversation-id, but that does not comply with the FIPA protocol, than the method handleOutOfSequence would be called.

    This class can be extended by the programmer by overriding all the needed handle methods or, in alternative, appropriate behaviours can be registered for each handle via the registerHandle-type of methods. This last case is more difficult to use and proper care must be taken to properly use the DataStore of the Behaviour as a shared memory mechanism with the registered behaviour.

    Read carefully the section of the JADE programmer's guide that describes the usage of this class.

    Version:
    $Date$ $Revision$
    Author:
    Fabio Bellifemine - TILAB, Giovanni Caire - TILAB, Marco Monticone - TILAB
    See Also:
    ContractNetInitiator, AchieveREResponder, Serialized Form

    • Field Detail

      • RESPONSE_KEY

        public final String RESPONSE_KEY
        Deprecated.
        Use REPLY_KEY

      • PROPOSE_ACCEPTANCE_KEY

        public final String PROPOSE_ACCEPTANCE_KEY
        Deprecated.
        Use either ACCEPT_PROPOSAL_KEY or REJECT_PROPOSAL_KEY according to the message that has been received

      • RESULT_NOTIFICATION_KEY

        public final String RESULT_NOTIFICATION_KEY
        Deprecated.
        Use REPLY_KEY

      • INITIATION_KEY

        public final String INITIATION_KEY
        Key to retrieve from the DataStore of the behaviour the initiation ACLMessage that triggered this responder session

      • RECEIVED_KEY

        public final String RECEIVED_KEY
        Key to retrieve from the DataStore of the behaviour the last received ACLMessage

      • REPLY_KEY

        public final String REPLY_KEY
        Key to set into the DataStore of the behaviour the new ACLMessage to be sent back to the initiator as a reply.

    • Constructor Detail

      • ContractNetResponder

        public ContractNetResponder​(Agent a,
                            MessageTemplate mt,
                            DataStore store)
        Constructor of the behaviour.
        Parameters:
        a - is the reference to the Agent object
        mt - is the MessageTemplate that must be used to match the initiator message. Take care that if mt is null every message is consumed by this protocol. The best practice is to have a MessageTemplate that matches the protocol slot; the static method createMessageTemplate might be usefull.
        store - the DataStore for this protocol behaviour

    • Method Detail

      • registerPrepareResponse

        public void registerPrepareResponse​(Behaviour b)
        Deprecated.
        Use registerHandleCfp() instead.

      • registerPrepareResultNotification

        public void registerPrepareResultNotification​(Behaviour b)
        Deprecated.
        Use registerHandleAcceptProposal() instead.

      • handleCfp

        protected ACLMessage handleCfp​(ACLMessage cfp)
                        throws RefuseException,
                               FailureException,
                               NotUnderstoodException
        Redefine this method to call prepareResponse()
        Overrides:
        handleCfp in class SSContractNetResponder
        Parameters:
        cfp - the initial CFP message to handle.
        Returns:
        the reply message to be sent back to the initiator. Returning a message different than PROPOSE (or returning null) terminates the protocol.
        Throws:
        RefuseException - if the CFP is refused. Throwing a RefuseException has the same effect as returning a REFUSE message, but automatically manages the :content slot.
        FailureException - if there is an error serving the CFP. Throwing a FailureException has the same effect as returning a FAILURE message, but automatically manages the :content slot.
        NotUnderstoodException - if the CFP content is not understood. Throwing a NotUnderstoodException has the same effect as returning a NOT_UNDERSTOOD message, but automatically manages the :content slot.

      • handleAcceptProposal

        protected ACLMessage handleAcceptProposal​(ACLMessage cfp,
                                          ACLMessage propose,
                                          ACLMessage accept)
                                   throws FailureException
        Redefine this method to call prepareResultNotification()
        Overrides:
        handleAcceptProposal in class SSContractNetResponder
        Parameters:
        cfp - the initial CFP message.
        propose - the PROPOSE message sent back as reply to the initial CFP message.
        accept - the received ACCEPT_PROPOSAL message.
        Returns:
        the reply message to be sent back to the initiator.
        Throws:
        FailureException - if there is an error serving the ACCEPT_PROPOSAL. Throwing a FailureException has the same effect as returning a FAILURE message, but automatically manages the :content slot.

      • registerHandleCfp

        public void registerHandleCfp​(Behaviour b)
        Redefine this method so that the HANDLE_CFP state is not registered as first state
        Overrides:
        registerHandleCfp in class SSContractNetResponder
        Parameters:
        b - the Behaviour that will handle this state

      • sessionTerminated

        protected void sessionTerminated()
        This method can be redefined by protocol specific implementations to take proper actions after the completion of the current protocol session.

      • createMessageTemplate

        public static MessageTemplate createMessageTemplate​(String iprotocol)
        This static method can be used to set the proper message Template (based on the interaction protocol and the performative) to be passed to the constructor of this behaviour.
        See Also:
        FIPANames.InteractionProtocol

      • onStart

        public void onStart()
        Description copied from class: Behaviour
        This method is just an empty placeholders for subclasses. It is executed just once before starting behaviour execution. Therefore, it acts as a prolog to the task represented by this Behaviour.
        Overrides:
        onStart in class Behaviour

      • registerHandleOutOfSequence

        public void registerHandleOutOfSequence​(Behaviour b)
        This method allows to register a user defined Behaviour in the HANDLE_OUT_OF_SEQ state. This behaviour would override the homonymous method. This method also sets the data store of the registered Behaviour to the DataStore of this current behaviour. The registered behaviour can retrieve the out of sequence ACLMessage object received from the datastore at the RECEIVED_KEY key.
        Parameters:
        b - the Behaviour that will handle this state

      • reset

        public void reset()
        Reset this behaviour.
        Overrides:
        reset in class FSMBehaviour

      • registerDSState

        protected void registerDSState​(Behaviour b,
                               String name)
        Utility method to register a behaviour in a state of the protocol and set the DataStore appropriately