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Class JavaAgent.resource.cdl.CDLInterpreter

java.lang.Object
   |
   +----JavaAgent.resource.Interpreter
           |
           +----JavaAgent.resource.cdl.CDLInterpreter

public class CDLInterpreter
extends Interpreter

This Interpreter manages storage and retrieval of capabilities for a capability broker. Brokers are implemented as extensions of Agent Name Servers (ANSs). To know about this Interpreter the ANS should receive a message from its initialization file telling it about this resource and associating it with the name capabilities. Now all messages to the ANS refering to the ontology capabilities will be handled by an instance of this CDLInterpreter.

A CDLInterpreter maintains the capability descriptions of agents advertising their capabilities in CDL (capability storage). On request, a CDLInterpreter can find problem-solving agents for a given problem (capabiliy retrieval). All messages to a CDLInterpreter are ultimately handled by the function interpretMessage(KQMLmessage, Agent) as described below.

traceStream

CDLInterpreter()

addCapability(String, KQMLmessage, Agent): This function gets called when an agent wants to advertise a new capability.
brokerAll(String, CDLDescription, Agent): This function gets called when an agent wants to contract other agents through the broker that can solve the problem described in the given CDLDescription.
brokerOne(String, CDLDescription, Agent): This function gets called when an agent wants to contract another agent through the broker that can solve the problem described in the given CDLDescription.
interpretMessage(KQMLmessage, Agent): This function is called when the broker receives a KQMLmessage with the ontology capabilities.
loadOntology(URL, Agent): This function loads the action ontology for this CDLInterpreter.
recommendAll(String, CDLDescription, Agent): This function gets called when an agent wants to find other agents that can solve the problem described in the given CDLDescription.
recommendOne(String, CDLDescription, Agent): This function gets called when an agent wants to find another agent that can solve the problem described in the given CDLDescription.

traceStream

 public static FileOutputStream traceStream

CDLInterpreter

 public CDLInterpreter()

interpretMessage

 public void interpretMessage(KQMLmessage message,
                              Agent receiver) throws InterpretationException

This function is called when the broker receives a KQMLmessage with the ontology capabilities. The following performatives are currently accepted:

load-ontology calls loadOntology(...)
advertise calls addCapability(...)
recommend-one calls recommendOne(...)
recommend-all calls recommendAll(...)
broker-one calls brokerOne(...)
broker-all calls brokerAll(...)

Parameters:: message - the KQMLmessage to be interpreted here; receiver - the Agent to which this CDLInterpreter belongs and which has received the message
Throws: InterpretationException: An exception will occur if this CDLInterpreter fails to process this message for some reason.
Overrides:: interpretMessage in class Interpreter

loadOntology

 protected void loadOntology(URL ontologyURL,
                             Agent receiver) throws IOException

This function loads the action ontology for this CDLInterpreter. This function should only be called for the broker. It opens the given URL and reads expressions in brackets from there. Each expression is interpreted as a CDLDescription.

Parameters:: ontologyURL - the URL that specifies where to find the ontology; receiver - should be the ANS Agent

addCapability

 protected void addCapability(String agent,
                              KQMLmessage message,
                              Agent receiver) throws InterpretationException

This function gets called when an agent wants to advertise a new capability. For this to be a valid capability description the performative must be perform or achieve, the specified receiver must be the agent that advertised the capability, the content language must be CDL, and the content must be a correct CDL expression.

Parameters:: agent - the name of the agent advertising the capability; message - the KQML that has the capability description as its content; receiver - the agent that has received this message, i.e. the broker that owns this CDLInterpreter
Throws: InterpretationException: An exception will occur if the given capability description cannot be processed, e.g. if the content field does not contain a valid CDL expression.

recommendOne

 protected void recommendOne(String agent,
                             CDLDescription task,
                             Agent receiver) throws InterpretationException

This function gets called when an agent wants to find another agent that can solve the problem described in the given CDLDescription.

Parameters:: agent - the name of the agent seeking a capability; task - the CDLDescription of the task to be performed; receiver - the agent that has received this message, i.e. the broker that owns this CDLInterpreter
Throws: InterpretationException: An exception will occur if

recommendAll

 protected void recommendAll(String agent,
                             CDLDescription task,
                             Agent receiver) throws InterpretationException

This function gets called when an agent wants to find other agents that can solve the problem described in the given CDLDescription.

Parameters:: agent - the name of the agent seeking a capability; task - the CDLDescription of the task to be performed; receiver - the agent that has received this message, i.e. the broker that owns this CDLInterpreter
Throws: InterpretationException: An exception will occur if

brokerOne

 protected void brokerOne(String agent,
                          CDLDescription task,
                          Agent receiver) throws InterpretationException

This function gets called when an agent wants to contract another agent through the broker that can solve the problem described in the given CDLDescription.

Parameters:: agent - the name of the agent seeking a capability; task - the CDLDescription of the task to be performed; receiver - the agent that has received this message, i.e. the broker that owns this CDLInterpreter
Throws: InterpretationException: An exception will occur if

brokerAll

 protected void brokerAll(String agent,
                          CDLDescription task,
                          Agent receiver) throws InterpretationException

This function gets called when an agent wants to contract other agents through the broker that can solve the problem described in the given CDLDescription.

Parameters:: agent - the name of the agent seeking a capability; task - the CDLDescription of the task to be performed; receiver - the agent that has received this message, i.e. the broker that owns this CDLInterpreter
Throws: InterpretationException: An exception will occur if

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