Package org.elasticsearch.common.util

Class CollectionUtils

java.lang.Object
org.elasticsearch.common.util.CollectionUtils
public class CollectionUtils
extends java.lang.Object
Collections-related utility methods.

  • Constructor Summary

    Constructors
    Constructor Description
    CollectionUtils()  

  • Method Summary

    Modifier and Type Method Description
    static <E> java.util.List<E> appendToCopy​(java.util.Collection<E> collection, E element)
    Creates a copy of the given collection with the given element appended.
    static <E> java.util.ArrayList<E> arrayAsArrayList​(E... elements)  
    static <E> java.util.ArrayList<E> asArrayList​(E first, E... other)  
    static <E> java.util.ArrayList<E> asArrayList​(E first, E second, E... other)  
    static <R,​ T> java.util.Map<R,​T> copyMap​(java.util.Map<R,​T> map)
    Returns an unmodifiable copy of the given map.
    static <E> java.util.List<java.util.List<E>> eagerPartition​(java.util.List<E> list, int size)  
    static void ensureNoSelfReferences​(java.lang.Object value, java.lang.String messageHint)
    Deeply inspects a Map, Iterable, or Object array looking for references back to itself.
    static boolean isEmpty​(java.lang.Object[] array)
    Checks if the given array contains any elements.
    static <E> java.util.ArrayList<E> iterableAsArrayList​(java.lang.Iterable<? extends E> elements)  
    static <E> java.util.ArrayList<E> newSingletonArrayList​(E element)  
    static <T> java.util.List<T> rotate​(java.util.List<T> list, int distance)
    Return a rotated view of the given list with the given distance.
    static void sort​(com.carrotsearch.hppc.ObjectArrayList<byte[]> array)  
    static void sort​(org.apache.lucene.util.BytesRefArray bytes, int[] indices)  
    static void sortAndDedup​(com.carrotsearch.hppc.ObjectArrayList<byte[]> array)  
    static int sortAndDedup​(org.apache.lucene.util.BytesRefArray bytes, int[] indices)  
    static int[] toArray​(java.util.Collection<java.lang.Integer> ints)  

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • CollectionUtils

      public CollectionUtils()

  • Method Details

    • isEmpty

      public static boolean isEmpty​(java.lang.Object[] array)
      Checks if the given array contains any elements.
      Parameters:
      array - The array to check
      Returns:
      false if the array contains an element, true if not or the array is null.

    • rotate

      public static <T> java.util.List<T> rotate​(java.util.List<T> list, int distance)
      Return a rotated view of the given list with the given distance.

    • sortAndDedup

      public static void sortAndDedup​(com.carrotsearch.hppc.ObjectArrayList<byte[]> array)

    • sort

      public static void sort​(com.carrotsearch.hppc.ObjectArrayList<byte[]> array)

    • toArray

      public static int[] toArray​(java.util.Collection<java.lang.Integer> ints)

    • ensureNoSelfReferences

      public static void ensureNoSelfReferences​(java.lang.Object value, java.lang.String messageHint)
      Deeply inspects a Map, Iterable, or Object array looking for references back to itself.
      Parameters:
      value - The object to evaluate looking for self references
      messageHint - A string to be included in the exception message if the call fails, to provide more context to the handler of the exception
      Throws:
      java.lang.IllegalArgumentException - if a self-reference is found

    • copyMap

      public static <R,​ T> java.util.Map<R,​T> copyMap​(java.util.Map<R,​T> map)
      Returns an unmodifiable copy of the given map.
      Parameters:
      map - Map to copy
      Returns:
      unmodifiable copy of the map

    • sort

      public static void sort​(org.apache.lucene.util.BytesRefArray bytes, int[] indices)

    • sortAndDedup

      public static int sortAndDedup​(org.apache.lucene.util.BytesRefArray bytes, int[] indices)

    • iterableAsArrayList

      public static <E> java.util.ArrayList<E> iterableAsArrayList​(java.lang.Iterable<? extends E> elements)

    • arrayAsArrayList

      public static <E> java.util.ArrayList<E> arrayAsArrayList​(E... elements)

    • asArrayList

      public static <E> java.util.ArrayList<E> asArrayList​(E first, E... other)

    • asArrayList

      public static <E> java.util.ArrayList<E> asArrayList​(E first, E second, E... other)

    • appendToCopy

      public static <E> java.util.List<E> appendToCopy​(java.util.Collection<E> collection, E element)
      Creates a copy of the given collection with the given element appended.
      Parameters:
      collection - collection to copy
      element - element to append

    • newSingletonArrayList

      public static <E> java.util.ArrayList<E> newSingletonArrayList​(E element)

    • eagerPartition

      public static <E> java.util.List<java.util.List<E>> eagerPartition​(java.util.List<E> list, int size)