Intelligent
Architectures
for Electronic
Commerce
Prolog/JADE Tutorial
Overview
1. JADE
2. CIAO Prolog
3. Prolog and JADE
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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1. JADE
• Standard platform for agent communication
• Provides useful services:
– Visualisation of messages;
– Sending/receiving messages manually;
– GUI, etc.
• We need to use some such platform to run our
agents, otherwise how would we test them?
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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1. JADE
Container
Agent
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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2. CIAO Prolog
• Efficient, free implementation of Prolog
• Higher-level than Java, C++, Delphi:
– Allows symbolic reasoning
– Terse syntax
• Common complaints:
–
–
–
–
Non-intuitive and outlandish
Difficult to understand
Inefficient
Odd choice for a programming language (if it is
not Java it is simply not cool…)
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3. Prolog and JADE
• Means to “agentify” Prolog programs
• Prolog programs may then:
– Send messages to other agents
– Receive messages from other agents
• Prolog can then “talk” to any other languages
– Current examples are all Prolog agents
• Our Prolog agents were isolated from the rest
of the world!
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.1 Connecting Prolog/Jade
• JADE is for Java, not Prolog….
• One solution:
– Prolog process has a “proxy” Java agent in JADE
– Prolog process sends and receives messages via
proxy agent
– Diagrammatically
Ag1
Ag2
Ag3
Ag4
Prolog
JADE
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.2 Proxy Agent
• Proxy agent is a simple Java program
• Reads from/writes to a socket open on a port
• Prolog program sends a message via proxy:
– Writes term onto socket
– Term must be in a specific format (more later…)
• Proxy agent reads in Prolog term (message to
be sent) and translates it onto FIPA-ACL
• Creation and registration of proxy agents is
performed via StarterAgent
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Timothy J Norman and Wamberto Vasconcelos
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3.3 StarterAgent (1)
• Each Prolog process needs a proxy agent
• Prolog cannot start an agent in JADE
• Solution: an agent inside JADE who is
responsible for starting up proxy agents!
• This is what StarterAgent is
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.3 StarterAgent (2)
• Started up manually using JADE’s service:
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.3 StarterAgent (3)
• Then you should type on the pop-up window:
Name of the Starter Agent
JAVA Class
Parameters: Port Number and “verbose” option
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.3 StarterAgent (4)
Look!!
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.3 StarterAgent (5)
• How to get hold of StarterAgent:
1.Copy folder JADE-InterAgent into your jade folder
2.Add
c:\jade\JADE-InterAgent
to your CLASSPATH
• You can now start up your StarterAgent as
before
• Choose a port which is not being used to use
as a parameter when starting the agent
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (1)
• Download file agent.pl
• Load it in CIAO Prolog
• Type in
?- connect_to_jade(1450,ag1,starterAgentCool).
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (3)
1. Prolog connects to port 1450
2. Sends a request to the StarterAgent in the form
request(Me,[StarterAg],register(Me)))
3. Receives a message with the port of the Proxy
agent
inform(StarterAg,[Me],registered(Me,NewPort)))
3. Connects to the NewPort port
4. And that’s all!
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (5)
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (6)
Look!!
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (7)
• After process connects to the port, it can send
and receive messages via its proxy agent in
JADE.
• You can, for instance, send a message using
the JADE service, in order to test your Prolog
agent.
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (10)
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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3.4 The Prolog Part (11)
• There are predicates defined to send and
receive messages.
• Messages must be in the format
perf-name(id-sender,ListOfRecs, contents)
where ListOfRecs is a list of recipients’s id
• Please read the documentation in the file
agent.pl
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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4. Final Words
• No standard connection:
– We’re free to create and propose solutions
– How would you connect Prolog to JADE?
• This is state-of-the-practice stuff
– There might be problems…
– Let me know and I will try to help!
• Enjoy it!
Intelligent Architectures for Electronic Commerce
Timothy J Norman and Wamberto Vasconcelos
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