Class CollectionUtils


  • public final class CollectionUtils
    extends Object
    Utility class for Collections.
    • Method Detail

      • newArrayList

        @SafeVarargs
        public static <E> ArrayList<E> newArrayList​(E... elements)
        Creates a new ArrayList with the provided elements.
        Type Parameters:
        E - the elements' type
        Parameters:
        elements - the elements to add to the new ArrayList
        Returns:
        a new ArrayList with the provided elements
      • newLinkedList

        @SafeVarargs
        public static <E> LinkedList<E> newLinkedList​(E... elements)
        Creates a new LinkedList with the provided elements.
        Type Parameters:
        E - the elements' type
        Parameters:
        elements - the elements to add to the new LinkedList
        Returns:
        a new LinkedList with the provided elements
      • newHashSet

        @SafeVarargs
        public static <E> HashSet<E> newHashSet​(E... elements)
        Creates a new HashSet with the provided elements.
        Type Parameters:
        E - the elements' type
        Parameters:
        elements - the elements to add to the new HashSet
        Returns:
        a new HashSet with the provided elements
      • newTreeSet

        @SafeVarargs
        public static <E> TreeSet<E> newTreeSet​(E... elements)
        Creates a new TreeSet with the provided elements.
        Type Parameters:
        E - the elements' type
        Parameters:
        elements - the elements to add to the new TreeSet
        Returns:
        a new TreeSet with the provided elements
      • collect

        public static <C extends Collection<E>,​E> C collect​(Iterable<E> iterable,
                                                                  C outputCollection)
        Collects all the elements from the provided iterable into the provided collection.
        Type Parameters:
        C - The type of the collection
        E - The type of the iterable's elements
        Parameters:
        iterable - the iterable from which to read elements
        outputCollection - the collection where to add the iterable's elements
        Returns:
        the provided collection
      • addAll

        public static <E,​C extends Collection<E>> C addAll​(C dest,
                                                                 Iterable<E> source)
        Adds all the elements from the provided iterable into the provided collection.
        Type Parameters:
        E - type of the elements to add
        C - type of the collection where to add
        Parameters:
        dest - the collection where elements will be added
        source - the iterable where elements will be read from
        Returns:
        the provided collection