Files
2014-10-23 14:46:29 +02:00

41 lines
707 B
Java

import java.util.Optional;
import java.util.function.Function;
class Scratch
{
public static void main(String[] args) throws Exception
{
final Optional<Integer> i = foo();
System.out.println(i);
}
private static Optional<Integer> foo()
{
final Optional<String> s = returnsR(
"foo",
z -> {
if (z.isEmpty())
{
return Optional.empty();
}
else
{
return Optional.of("a string");
}
});
if (s.isPresent())
{
return Optional.of(1);
}
else
{
return Optional.of(2);
}
}
private static <R> R returnsR(String s, Function<String, R> f)
{
return f.apply(s);
}
}