Package org.openjdk.jmc.common.collection

Class IteratorToolkit

  • public class IteratorToolkit
extends Object
    Various methods that work with iterators.

    • Constructor Detail

      • IteratorToolkit

        public IteratorToolkit()

    • Method Detail

      • toList

        public static <T> List<T> toList​(Iterator<T> itr,
                                 int sizeHint)
        Place all elements of an iterator in a list.
        Type Parameters:
        T - input iterator type
        Parameters:
        itr - iterator
        sizeHint - a hint of how many elements there are
        Returns:
        a new list with all elements from the iterator

      • skipNulls

        public static <T> Iterator<T> skipNulls​(Iterator<T> itr)
        Wrap an iterator in a new iterator that skips all null values.
        Type Parameters:
        T - input iterator type
        Parameters:
        itr - input iterator that may produce null values
        Returns:
        a new iterator that will never produce null values

      • filter

        public static <T> Iterator<T> filter​(Iterator<T> itr,
                                     Predicate<? super T> filter)
        Wrap an iterator in a new iterator that filters out values based on a predicate.
        Type Parameters:
        T - input iterator type
        Parameters:
        itr - input iterator
        filter - filter predicate
        Returns:
        a new iterator that only contains values where the filter evaluates to true

      • of

        public static <T> Iterator<T> of​(T[] elements)
        Iterator that iterates over an array. Hopefully faster than Arrays.asList(...).iterator() since there are no concurrency checks.
        Type Parameters:
        T - input iterator type
        Parameters:
        elements - elements to iterate over
        Returns:
        an iterator