Split string in a stream Java

Harshal :

I have a POJO class Product

List<Product> list = new ArrayList<>();
list.add(new Product(1, "HP Laptop Speakers", 25000));
list.add(new Product(30, "Acer Keyboard", 300));
list.add(new Product(2, "Dell Mouse", 150));

Now I want to split the list to get output as HP-Laptop-Speakers&&Acer-Keyboard&&Dell-Mouse.

I just want a single liner in stream. So far I have managed to get

Optional<String> temp = list.stream().
                   map(x -> x.name).
                   map(x -> x.split(" ")[0]).
                   reduce((str1, str2) -> str1 + "&&" + str2);
System.out.println(temp.get());

Output: HP&&Acer&&Dell

Can someone help me out. Thanks in advance.

Patrick Parker :

First, the split() operation is not necessary. While you could split all the pieces and then join them together like that, it is far simpler to use a replace or replaceAll call instead.

Secondly, the reduce operation will not be very efficient since it is creating lots of intermediary Strings and StringBuilders. Instead, you should use the String joining Collector, which is more efficient:

 String temp = list.stream()
              .map(x -> x.name.replace(" ", "-"))
              .collect(Collectors.joining("&&"));