Hey, explorers! Welcome back to our ongoing voyage through the vast expanse of functional programming with Java. So far, we’ve embarked on thrilling escapades with stream operations, intermediaries, and laziness. Today, we’re about to uncover a trio of hidden gems: the IntStream, LongStream, and DoubleStream – Java’s very own primitive streams.
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Introducing the Primitive Streams Trio
Behold the triumvirate of IntStream, LongStream, and DoubleStream. These specialized streams are Java’s secret weapons for efficiently handling primitive data types. The tales of their prowess center around performance optimization and mathematical might. Let’s explore how these streams can be harnessed to amplify your code’s elegance and efficiency.
Calculating the Average Rating with IntStream
Imagine a scenario where you’re entrusted with judging a collection of books based on their ratings. Your quest: calculate the average rating and determine whether the collection is worth its weight in gold. Here’s a glimpse of how IntStream steps into the limelight:
double averageRating = books.stream()
.mapToDouble(Book::getRating)
.average()
.getAsDouble();
1 - Stream Creation: The journey begins as our stream materializes, ready to unfurl its magic.
2 - Mapping to Primitive Doubles: With the mapToDouble operation, we elegantly convert the stream of books into a stream of primitive doubles – the ratings.
3 - Calculate the Average: The magic of primitive streams reveals itself as we effortlessly invoke the average method on our double stream. No more cumbersome calculations!
4 - Basking in the Glory: The triumphant moment arrives as the average rating emerges, casting its light upon us.
The Power of Mapping to Objects
But wait, there’s more! The primitive streams offer a unique superpower: the ability to transform primitive streams into object streams and vice versa. The method mapToObj allows you to elegantly step across the boundary between primitives and objects, opening doors to a whole new level of versatility.
Unleashing the Stream Creators: of and boxed
Creating these powerful primitive streams is a breeze with the of method:
IntStream intStream = IntStream.of(1, 2, 3, 4, 5);
LongStream longStream = LongStream.of(10L, 20L, 30L);
DoubleStream doubleStream = DoubleStream.of(0.1, 0.2, 0.3);
And when you’re ready to traverse back from the world of primitives to the realm of objects, the boxed method gracefully escorts you:
Stream<Integer> integerStream = intStream.boxed();
Stream<Long> longStreamObjects = longStream.boxed();
Stream<Double> doubleStreamObjects = doubleStream.boxed();
Conquering Costly Boxing and Unboxing
One of the prime benefits of these primitive streams is their ability to sidestep the costly process of boxing and unboxing. By leveraging the power of primitives, you embrace better performance without the overhead of object conversion.
The Grand Finale
As we conclude our exploration of primitive streams, remember that they’re more than just streams – they’re efficient tools that breathe life into your code. Whether it’s harnessing mathematical might, optimizing performance, or effortlessly managing primitives, these streams stand ready to enhance your functional programming odyssey.
In our next adventure, we’ll unravel the mysteries of essential methods unique to these primitive streams. So, until then, keep embracing the power of streams and navigating the wonders of functional programming.
Until we meet again on this exhilarating journey – farewell!
You can find the repo for this section of the course Here