Observable Notify Multiple variables change

Question

How I can Notify on Multiple variables update?

Is there any method to detect and separatenotifyObservers?

public class AnimalWeightObservable extends Observable {

    public long animalId;

    public long weigh;

    public long getAnimalId() {
        return animalId;
    }

    public AnimalWeightObservable setAnimalId(long animalId) {
        this.animalId = animalId;
        this.setChanged();
        this.notifyObservers(animalId);
        return this;
    }

    public long getWeigh() {
        return weigh;
    }

    public AnimalWeightObservable setWeigh(long weigh) {
        this.weigh = weigh;
        this.setChanged();
        this.notifyObservers(weigh);
        return this;
    }

}

How can detect witch variable has changed?

Answer 1

How about wrapping animalId and weight inside another type: for example AnimalProperty

class AnimalProperty<T> {
    String propertyName;
    T property;

    AnimalProperty(String name, T property) {
        this.propertyName = name;
        this.property = property;
    }
}

so your code would look like this:

public class AnimalWeightObservable extends Observable {

    public AnimalProperty animalId;

    public AnimalProperty weigh;

    //...
    //...

    public AnimalWeightObservable setWeigh(AnimalProperty weigh) {
        this.weigh = weigh;
        this.setChanged();
        this.notifyObservers(weigh);
        return this;
    }
}

then in the Observer's update(...) method switch on the propertyName to know which property is updated