NullPointerException help me please [duplicate]

This question already has an answer here:

• What is a Null Pointer Exception, and how do I fix it? 12 answers

Can anybody explain to me why does it give null pointer

public void earliestTimeBfs(HashMap times) { this.times = new HashMap<>();

    Vertex<V, E> vOrig = this.graph.getVertex(0);

    Deque<Vertex<V, E>> qaux = new LinkedList<>();

    qaux.add(vOrig);

    while (!qaux.isEmpty()) {
        vOrig = qaux.remove();
        for (Object edge : this.graph.outgoingEdges(vOrig)) {
            Vertex<V, E> vAdj = this.graph.opposite(vOrig, (Edge) edge);
            Integer[] aux = times.get(((Activity) this.graph.getVertex(vAdj.getElement()).getElement()).getId());
            if (aux == null) {  
                Integer[] arrayaux = new Integer[5];
                arrayaux[0] = times.get(((Activity) this.graph.getVertex(vOrig.getElement()).getElement()).getId())[1];
                arrayaux[1] = arrayaux[0] + ((Activity) this.graph.getVertex(vAdj.getElement()).getElement()).getDuration();
                times.put(((Activity) graph.getVertex(vAdj.getElement()).getElement()).getId(), arrayaux);
            } else if (times.get(((Activity) graph.getVertex(vOrig).getElement()).getId())[1] > aux[0]) {
                aux[0] = times.get(((Activity) graph.getVertex(vOrig.getElement()).getElement()).getId())[1];
                aux[1] = aux[0] + ((Activity) graph.getVertex(vAdj.getElement()).getElement()).getDuration();
                times.put(((Activity) graph.getVertex(vAdj).getElement()).getId(), aux);

            }
            qaux.add(vAdj);
        }
    }
}

So the problem is that it gives nullPointerException when i do arrayaux[0] = times.get(((Activity) this.graph.getVertex(vOrig.getElement()).getElement()).getId())[1]; can anybody help me? thank you!