spliterator()

Example

Utilize a Spliterator to iterate through the items in a list.

import java.util.ArrayList;
import java.util.Spliterator;

public class Main {
  public static void main(String[] args) {

    // Make a collection
 ArrayList<String> cars = new ArrayList<String>();
    cars.add("Volvo");
    cars.add("BMW");
    cars.add("Ford");
    cars.add("Mazda");

// Get the spliterator and split it
    Spliterator<String> it1 = cars.spliterator();
    Spliterator<String> it2 = it1.trySplit();

    // Loop through the first spliterator
    System.out.println("First spliterator");
    while( it1.tryAdvance( (n) -> { System.out.println(n); } ) );

    // Loop through the second spliterator
    System.out.println("\nSecond spliterator");
    while( it2.tryAdvance( (n) -> { System.out.println(n); } ) );
  }
}

Note: The syntax while(it1.tryAdvance((n) -> { System.out.println(n); })); is equivalent to:

boolean x = it1.tryAdvance( (n) -> { System.out.println(n); });
while(x) {
  x = it1.tryAdvance( (n) -> { System.out.println(n); });
}

Definition and Usage

The spliterator() method retrieves a Spliterator for the list, which is a specialized type of iterator.

To understand how to work with iterators, refer to our Java Iterator tutorial.

The Spliterator differs significantly from a standard iterator. Its primary objective is to partition a collection into smaller segments, enabling independent processing by separate threads. The Spliterator interface encompasses two pivotal methods:

1. trySplit(): Generates a new spliterator capable of traversing approximately half of the elements accessible to the original spliterator, leaving the remaining half for the original.
2. tryAdvance(Consumer action): Progresses to the next available item for the spliterator and attempts to execute an action on it. If no next item exists, it returns false. The action can be specified via a lambda expression.

Syntax

public Spliterator spliterator()

Technical Details