Java 8：从流中提取子流

Question

I have a stream of Objects, from which I need to extract a Stream which has only some of the object attributes.

For example, from a Stream<Car> , I need to extract a Stream<CarDetails> .

Car {
   String name;
   String model;
   Engine e;
   CarType t;
   ...
}

I want to extract a Stream of objects having type CarDetails :

CarDetails {
   String name;
   String model;
}

Answer 1

You can achieve this with map , assuming you have the required CarDetails constructor :

Stream<Car> cars = ...
Stream<CarDetails> details = cars.map(c -> new CarDetails(c.getName(),c.getModel()));