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@Adverte

Adverte/store.java

Created July 10, 2020 16:55
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какой-то мудрёный стрим
Raw
store.java
list.stream()
.collect(Collectors.collectingAndThen(
Collectors.groupingBy(A::getId, Collector.of(
() -> new A<>(null, 0d, null), (acc, a) -> {
acc.setId(a.getId());
acc.setQuant(Double.sum(acc.getQuant(), a.getQuant()));
acc.setType(a.getType());
}, (a1, a2) -> {
a1.setQuant(Double.sum(a1.getQuant(), a2.getQuant()));
return a1;
}, a -> new B<>(a.getId(), new NewClass(a.getQuant(), a.getType())) )), Map::values ))
// Set .forEach(System.out::println);
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