@Testpublic void test(){

List list = new ArrayList<>(); list.add(40d); list.add(30.00); list.add(10d); list.add(7d); list.add(2d); list.add(1.00); list.add(0.05); list.add(0.3999); list.add(0.0001); List objects = new ArrayList<>(); int count = 1000000; double sum = list.stream().mapToDouble(e -> e).sum(); System.out.println(sum); list = list.stream().sorted().collect(Collectors.toList()); for (int i = 0; i< count; i++){ double random = Math.random(); double s = 0d; for (double d:list){ s = s + d; if((random*sum)<=s){ objects.add(d); break; } } } System.out.println(objects.size()); Map collect = objects.stream().collect(Collectors.groupingBy(e -> e, Collectors.counting())); Map objectObjectHashMap = new HashMap<>(); System.out.println(collect); System.out.println(collect.values().stream().mapToDouble(e->e).sum()); for (Double s : collect.keySet()){ objectObjectHashMap.put(s, collect.get(s)*100d/count); } System.out.println(objectObjectHashMap); System.out.println(objectObjectHashMap.values().stream().mapToDouble(e->e).sum());}