public void sampleDemo {

        for (int i = 0 ; i < 30 ; i++) {
            makeJs (hashMapOutput) {

            }
        }
    }

    public static void makeJs(HashMap hashMapOutput) {
        String key = "" ;
        Gson obj = new Gson();
        ArrayList arr = new ArrayList();
        Employee emp = new Employee();
        Invoice inv = new Invoice();
        Iterator iterator = hashMapOutput.keyset().iterator();

        while (iterator.hasNext()) {
            key = (String)iterator.next();
            ArrayList arraylist = (ArrayList)hashMapOutput.get(key);
            emp = arraylist.get(0);
            inv = arrayList.get(1);
        }

        arr.add(emp);
        arr.add(inv);

        string value1 = obj.toJson(arr);

    }