This is a really simple Petrinet written in Java.
Here is an example on how to use it and display it in a really simple and basic "gui".
package petrinet.gui;
import petrinet.logic.Arc;
import petrinet.logic.Petrinet;
import petrinet.logic.Place;
import petrinet.logic.Transition;
public class Alternating {
public static void main(String[] args) {
Petrinet pn = new Petrinet("Alternating");
Transition t1 = pn.transition("t1");
Transition t2 = pn.transition("t2");
Place p1 = pn.place("p1", 1);
Place p2 = pn.place("p2");
Arc a1 = pn.arc("a1", p1, t1);
Arc a2 = pn.arc("a2", t1, p2);
Arc a3 = pn.arc("a3", p2, t2);
Arc a4 = pn.arc("a4", t2, p1);
PetrinetGUI.displayPetrinet(pn);
}
}