AgentBase for SICStus Prolog

AgentBase for SICStus Prolog
Swedish Institute of Computer Science
http://www.sics.se/isl/agentbase/

Example - Jeval - multi user GUI

This is a simple example of communication between Java and Prolog where Prolog is the server and a Java applet is client. In this example multiple applets can access the same Prolog application.

Instructions

1. Change directory to examples/jeval/ and start the example with

sicstus -l multi_eval

Normally the server will listen for http at port 30002.

2. Browse to http://localhost:30002/

Each time a browser access the server it will send a page with a Java applet. The applet then "logs-in" to the server and request the application dependent Java code (BeanShell scripted). In this example it is the application dependent code describes a GUI:

   jeval:jeval(User, '\c
               jevalApplet.setLayout(new GridLayout(0,1));\c
               jevalApplet.add(new Label("Enter expression"));\c
               expr = new TextField("5 * 7");\c
               jevalApplet.add(expr);\c
               result = new Label("Result:");\c
               jevalApplet.add(result);\c
               button = new Button("Evaluate!");\c
               jevalApplet.add(button);\c
               jeval.addActionListener("button");\c
               jeval.addActionListener("expr");\c
               jevalApplet.validate();\c
               jevalApplet.repaint();').

When you have successfully started the multi_eval example and browsed to the server you will see a small applet looking like the screenshot below.

Source Code

The code of the Jeval example multi_eval.pl.