Java provides different stream classes to facilitate working with sequences of elements. These classes are categorized into two main types:
1. Base Stream Classes
- Stream: The fundamental interface that defines the core operations for working with streams. It provides methods for filtering, mapping, reducing, and collecting elements.
- IntStream: A specialized stream for working with sequences of int values. It provides methods for working with primitive integers.
- LongStream: Similar to IntStream, this stream handles sequences of long values.
- DoubleStream: A stream designed for working with sequences of double values.
2. Stream Builders
- Stream.Builder: Used to create streams from a collection of elements. It allows you to add elements one by one.
- IntStream.Builder: Specifically used to build streams of int values.
- LongStream.Builder: Used to build streams of long values.
- DoubleStream.Builder: Used to build streams of double values.
Example:
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class StreamClassesExample {
public static void main(String[] args) {
// Creating a stream from a list
List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
Stream<Integer> stream = numbers.stream();
// Using IntStream to calculate the sum of squares
int sumOfSquares = IntStream.of(1, 2, 3, 4, 5)
.map(n -> n * n)
.sum();
// Building a stream using Stream.Builder
Stream<String> names = Stream.<String>builder()
.add("Alice")
.add("Bob")
.add("Charlie")
.build();
// Collecting elements from a stream
List<String> collectedNames = names.collect(Collectors.toList());
}
}These classes provide a powerful and flexible way to process data in Java, enabling efficient and concise code.
