Good morning everyone!

I was making the code for this method called ordersWithStatus(). The method should return informations about the orders. Such method returns a String obtained by concatenating all orders satisfying the criteria:

1. Only orders with a given status passed by argument to the method

2. The orders have to be sorted by: restaurant name, customer's first name, customer's last name, delivery time.

I don't understand why the method using the stream (the commented one) doesn't work, but the other one using Collections.sort() works. Expected: Napoli, Judi Dench : (19:00): M6->1 Napoli, Ralph Fiennes : (19:00): M1->2 M6->1 But was: Napoli, Ralph Fiennes : (19:00): M1->2 M6->1 Napoli, Judi Dench : (19:00): M6->1 I noted that using the stream, it seems that the method doesn't sort the output, it prints Ralph Fiennes first and then Judi Dench. What am I doing wrong with the stream? Could you please help me ?

Here is my code:

	/**
	 * Retrieve all order with a given status with all the relative details in text format.
	 * The list is sorted by name of restaurant, name of the customer, and delivery time.
	 * @param status the status to be matched
	 * @return textual representation of orders
	 */
	public String ordersWithStatus(OrderStatus status) {
	/* 	
		Set<String> outputSet = this.orders.stream()
		.filter(o->o.getStatus()==status)
		.sorted( Comparator.comparing(Order::getRestaurantName)
		.thenComparing(Order::getCustomerName1)
		.thenComparing(Order::getCustomerName2)
		.thenComparing(Order::getTime ))
		.map(Order::toString)
		.collect( Collectors.toSet() );

		String output = "";

		for (String order : outputSet){
			output+=order;
		}
		return output;
*/		
		// Pulling out each comparision step into a local reference
		Comparator<Order> byRestaurantName = (o1, o2) -> o1.getRestaurantName().
		compareTo(o2.getRestaurantName());
		
		Comparator<Order> byCustomer1name = (o1, o2) -> o1.getCustomerName1().
		compareTo(o2.getCustomerName1());
		
		Comparator<Order> byCustomer2name = (o1, o2) -> o1.getCustomerName2().
		compareTo(o2.getCustomerName2());
		
		Comparator<Order> byTime = (o1, o2) -> o1.getTime().
		compareTo(o2.getTime());
		
		List<Order> tempOrders = this.orders.stream().
		filter(o->o.getStatus()==status).
		collect(Collectors.toList());
		
		Collections.sort(tempOrders,
		 	byRestaurantName
			.thenComparing(byCustomer1name)
			.thenComparing(byCustomer2name)
			.thenComparing(byTime));

		String res = "";
		// for each order in the sorted orders list
		for (Order order : tempOrders){
			res+=order.toString();
		}

		return res;
	}