public class Main {
public static void main(String args[]) {
EventBus eventBus = new EventBus();
eventBus.chanel("/sistema/session/parametros").on(t -> System.out.println(t));
eventBus.chanel("/sistema/session/parametros").fire(new RegistraParametro("mi parametrito"));


}
}

public class RegistraParametro {

private String string;

public RegistraParametro(String string) {
this.string = string;

}

@Override
public String toString() {
return "RegistraParametro [string=" + string + "]";
}

}

import java.util.function.Function;

public interface Callbak { void apply(Object obj); }

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.function.Consumer;
import java.util.function.Function;

public class Chanel {

private List<Callbak> events = new ArrayList<>();

public void fire(Object event) {
events.forEach(p -> p.apply(event));
}

public void on(Callbak event) {
events.add(event);
}

}

import java.util.HashMap;

public class EventBus {

private HashMap<String, Chanel> chanels = new HashMap<>();

public Chanel chanel(String string) {
return chanels.computeIfAbsent(string, p -> new Chanel());

}

}