Java Scanner parsing input - parsing

Question

I have the the following input string:
1 imported box of chocolates at 10.00 1 imported bottle of perfume at 47.50
I would like to use the Java Scanner class to parse this input to create a list of product objects for example.
Please note the input line consists of multiple products (two in this case) as follows:
Quantity: 1
Name: imported box of chocolates
Price: 10.00
Quantity: 1
Name: imported bottle of perfume
Price: 47.50
Ideally I would like to parse the first product portion of the line and then the next product portion.
I know how to do this using regex etc but the question is:
What is the best way to use the Java Scanner to parse the input line?
Thank you.

Answer 1

I would just use splitting on space which is what Scanner does by default, and do the parsing myself according to the following rule.
ORDER := QUANTITY DESCRIPTION at PRICE ORDER | ""
QUANTITY := Integer
DESCRIPTION := String
PRICE := Float
For simplicity you can do it like below, you will have to include some error handling of course. A better option would be to use a tool like antlr which will do all the heavy lifting for you.
Scanner sc = new Scanner(System.in);
ArrayList<Product> products = new ArrayList<>();
while (sc.hasNext()) {
int quantity = sc.nextInt();
StringBuilder description = new StringBuilder();
while (!(String token = sc.next()).equals("at")) {
description.append(token);
}
float price = sc.nextFloat();
Product p = new Product(quantity, description.toString(), price);
products.add(product);
}
Hope this helps.