public static void main(String[] args) {
out.println("Gauss: " + MAX * (MAX + 1) / 2); // 500000500000
long sum = 0L;
for (long i = 0; i <= MAX; i++) {
sum = sum + i;
}
out.println("For loop: " + sum);
Long another =
Stream.iterate(0L, l -> ++l).limit(MAX + 1).collect(Collectors.summingLong(l -> l));
out.println("With a Stream of Long and Collectors.summingLong: " + another);
}
public static void main(String[] args) {
long total = colaboradores.stream().filter(c -> c.getSalario() > 5000).count();
System.out.println("total : " + total);
System.out.println("Nomes dos ricos\n");
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.map(c -> c.getNome())
.forEach(System.out::println);
System.out.println("\nCpf dos ricos\n");
List<String> cpfs =
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.map(c -> c.getCpf())
.collect(Collectors.toList());
cpfs.forEach(System.out::println);
System.out.println("\nRicos completos\n");
List<Colaborador> ricos =
colaboradores.stream().filter(c -> c.getSalario() > 5000).collect(Collectors.toList());
ricos.forEach(System.out::println);
System.out.println("\nCpf dos ricos\n");
double totalSalarios =
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.collect(Collectors.summingDouble(Colaborador::getSalario));
System.out.println("\nTotal dos salários " + totalSalarios);
long totalId =
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.collect(Collectors.summingLong(Colaborador::getId));
System.out.println("\nTotal dos ids " + totalId);
System.out.println("\nExibindo por ordem alfabética os nomes\n");
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.map(c -> c.getNome().toUpperCase())
.sorted()
.forEach(System.out::println);
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.map(c -> c.getNome().toUpperCase())
.sorted(Comparator.comparing(String::toUpperCase))
.forEach(System.out::println);
System.out.println("\nExibindo por ordem alfabética inversa os nomes\n");
colaboradores
.stream()
.filter(c -> c.getSalario() > 5000)
.sorted(Comparator.comparing(Colaborador::getNome).reversed())
.map(c -> c.getNome().toUpperCase())
.forEach(System.out::println);
}
// public static AggregationDescriptor<Object, Object, Long> buildCount() {
// return new AggregationDescriptor<Object, Object,
// Long>(AggregationDescriptor.Operation.COUNT);
// }
//
public static <A> Collector<A, ?, Long> buildSum(ToLongFunction<A> extractor) {
return Collectors.<A>summingLong(extractor);
// return AggregationDescriptor.SUM.apply(extractor);
}