proxy

import org.springframework.cglib.proxy.Enhancer
import org.springframework.cglib.proxy.MethodInterceptor
import org.springframework.cglib.proxy.MethodProxy

import java.lang.reflect.Method

class Data {
    Integer a = 0
    Integer b = 0
    Integer c = 0


    @Override
    public String toString() {
        return "Data{" +
                "a=" + a +
                ", b=" + b +
                ", c=" + c +
                '}';
    }
}

@FunctionalInterface
interface Subscriber {
    void receiveMessage(String type, Data data)
}

class Observable {
    Map<String, List<Subscriber>> subscribers = new HashMap<>()

    def notifyAll(String type, Data data) {
        subscribers.get('ANY').each { it.receiveMessage(type, data) }
        subscribers.get(type).each { it.receiveMessage(type, data) }
    }

    def subscribe(String type, Subscriber subscriber) {
        subscribers.putIfAbsent(type, new ArrayList<>())
        subscribers.get(type).add(subscriber)
    }

    def subscribe(List<String> types, Subscriber subscriber) {
        types.each { type ->
            subscribers.putIfAbsent(type, new ArrayList<>())
            subscribers.get(type).add(subscriber)
        }
    }
}

def observable = new Observable()

def enhancer = new Enhancer()
enhancer.setSuperclass(Data)
MethodInterceptor interceptor = { Object object, Method method, Object[] args, MethodProxy proxy ->
    if (method.getName().startsWith('set') && method.getName() != 'setProperty') {
//        println method.getName()
//        println args
//        println ''
        observable.notifyAll('SET_' + method.getName().substring(3), object as Data)
        return proxy.invokeSuper(object, args)
    } else {
        return proxy.invokeSuper(object, args)
    }
} as MethodInterceptor
enhancer.setCallback(interceptor)

observable.subscribe('ANY') { type, data -> println "$type" }
observable.subscribe(['SET_A', 'SET_B']) { type, data -> data.c = data.a + data.b }


Data data = (Data) enhancer.create()
data.a = 12
data.setB(10)

data