Sorting a list with stream.sorted() in Java

Question

I'm interested in sorting a list from a stream. This is the code I'm using:

list.stream()     .sorted((o1, o2)->o1.getItem().getValue().compareTo(o2.getItem().getValue()))     .collect(Collectors.toList()); 

Am I missing something? The list is not sorted afterward.

It should sort the lists according to the item with the lowest value.

for (int i = 0; i < list.size(); i++) {    System.out.println("list " + (i+1));    print(list, i); } 

And the print method:

public static void print(List<List> list, int i) {     System.out.println(list.get(i).getItem().getValue()); } 

Answer 1

This is not like Collections.sort() where the parameter reference gets sorted. In this case you just get a sorted stream that you need to collect and assign to another variable eventually:

List result = list.stream().sorted((o1, o2)->o1.getItem().getValue().                                    compareTo(o2.getItem().getValue())).                                    collect(Collectors.toList()); 

You've just missed to assign the result