Package jade.core.behaviours

Class ReceiverBehaviour

  • All Implemented Interfaces:
    Serializable, Serializable
    public final class ReceiverBehaviour
extends Behaviour
    Behaviour for receiving an ACL message. This class encapsulates a receive() as an atomic operation. This behaviour terminates when an ACL message is received. The method getMessage() allows to get the received message.
    Version:
    $Date$ $Revision$
    Author:
    Giovanni Rimassa - Universita' di Parma
    See Also:
    SenderBehaviour, Agent.receive(), ACLMessage, Serialized Form

    • Constructor Detail

      • ReceiverBehaviour

        public ReceiverBehaviour​(Agent a,
                         long millis,
                         MessageTemplate mt)
        This constructor creates a ReceiverBehaviour object that ends as soon as an ACL message matching a given MessageTemplate arrives or the passed millis timeout expires. The received message can then be got via the method getMessage.
        Parameters:
        a - The agent this behaviour belongs to, and that will receive() the message.
        millis - The timeout expressed in milliseconds, an infinite timeout can be expressed by a value < 0.
        mt - A Message template to match incoming messages against, null to indicate no template and receive any message that arrives.

      • ReceiverBehaviour

        public ReceiverBehaviour​(Agent a,
                         ReceiverBehaviour.Handle h,
                         long millis)
        Receive any ACL message, waiting at most millis milliseconds (infinite time if millis < 1). When calling this constructor, a suitable Handle must be created and passed to it. When this behaviour ends, some other behaviour will try to get the ACL message out of the handle, and an exception will be thrown in case of a time out. The following example code explains this: 
               // ReceiverBehaviour creation, e.g. in agent setup() method
       h = ReceiverBehaviour.newHandle(); // h is an agent instance variable
       addBehaviour(new ReceiverBehaviour(this, h, 10000); // Wait 10 seconds

       ...

       // Some other behaviour, later, tries to read the ACL message
       // in its action() method
       try {
         ACLMessage msg = h.getMessage();
         // OK. Message received within timeout.
       }
       catch(ReceiverBehaviour.TimedOut rbte) {
         // Receive timed out
       }
       catch(ReceiverBehaviour.NotYetReady rbnyr) {
         // Message not yet ready, but timeout still active
       }
        Parameters:
        a - The agent this behaviour belongs to.
        h - An Handle representing the message to receive.
        millis - The maximum amount of time to wait for the message, in milliseconds.
        See Also:
        ReceiverBehaviour.Handle, newHandle()

      • ReceiverBehaviour

        public ReceiverBehaviour​(Agent a,
                         ReceiverBehaviour.Handle h,
                         long millis,
                         MessageTemplate mt)
        Receive any ACL message matching the given template, witing at most millis milliseconds (infinite time if millis < 1. When calling this constructor, a suitable Handle must be created and passed to it.
        Parameters:
        a - The agent this behaviour belongs to.
        h - An Handle representing the message to receive.
        millis - The maximum amount of time to wait for the message, in milliseconds.
        mt - A Message template to match incoming messages against, null to indicate no template and receive any message that arrives.
        See Also:
        ReceiverBehaviour(Agent a, Handle h, long millis)

    • Method Detail

      • newHandle

        public static ReceiverBehaviour.Handle newHandle()
        Factory method for message handles. This method returns a new Handle object, which can be used to retrieve an ACL message out of a ReceiverBehaviour object.
        Returns:
        A new Handle object.
        See Also:
        ReceiverBehaviour.Handle

      • action

        public void action()
        Actual behaviour implementation. This method receives a suitable ACL message and copies it into the message provided by the behaviour creator. It blocks the current behaviour if no suitable message is available.
        Specified by:
        action in class Behaviour
        See Also:
        CompositeBehaviour

      • done

        public boolean done()
        Checks whether this behaviour ended.
        Specified by:
        done in class Behaviour
        Returns:
        true when an ACL message has been received.

      • reset

        public void reset()
        Resets this behaviour. This method allows to receive another ACLMessage with the same ReceiverBehaviour without creating a new object.
        Overrides:
        reset in class Behaviour