Package com.cedarsoftware.util

Class ArrayUtilities

java.lang.Object
com.cedarsoftware.util.ArrayUtilities
public final class ArrayUtilities extends Object
Handy utilities for working with Java arrays.
Author:
Ken Partlow, John DeRegnaucourt ([email protected])
Copyright (c) Cedar Software LLC

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

  • Field Details

    • EMPTY_OBJECT_ARRAY

      public static final Object[] EMPTY_OBJECT_ARRAY
      Immutable common arrays.

    • EMPTY_CLASS_ARRAY

      public static final Class[] EMPTY_CLASS_ARRAY

  • Method Details

    • isEmpty

      public static boolean isEmpty(Object array)
      This is a null-safe isEmpty check. It uses the Array static class for doing a length check. This check is actually .0001 ms slower than the following typed check:

      return array == null || array.length == 0;

      but gives you more flexibility, since it checks for all array types.
      Parameters:
      array - array to check
      Returns:
      true if empty or null

    • size

      public static int size(Object array)
      This is a null-safe size check. It uses the Array static class for doing a length check. This check is actually .0001 ms slower than the following typed check:

      return (array == null) ? 0 : array.length;

      Parameters:
      array - array to check
      Returns:
      true if empty or null

    • shallowCopy

      public static <T> T[] shallowCopy(T[] array)

      Shallow copies an array of Objects

      The objects in the array are not cloned, thus there is no special handling for multi-dimensional arrays.

      This method returns null if null array input.

      Type Parameters:
      T - the array type
      Parameters:
      array - the array to shallow clone, may be null
      Returns:
      the cloned array, null if null input

    • addAll

      public static <T> T[] addAll(T[] array1, T[] array2)

      Adds all the elements of the given arrays into a new array.

      The new array contains all of the element of array1 followed by all of the elements array2. When an array is returned, it is always a new array. 

       ArrayUtilities.addAll(null, null)     = null
 ArrayUtilities.addAll(array1, null)   = cloned copy of array1
 ArrayUtilities.addAll(null, array2)   = cloned copy of array2
 ArrayUtilities.addAll([], [])         = []
 ArrayUtilities.addAll([null], [null]) = [null, null]
 ArrayUtilities.addAll(["a", "b", "c"], ["1", "2", "3"]) = ["a", "b", "c", "1", "2", "3"]
      Type Parameters:
      T - the array type
      Parameters:
      array1 - the first array whose elements are added to the new array, may be null
      array2 - the second array whose elements are added to the new array, may be null
      Returns:
      The new array, null if null array inputs. The type of the new array is the type of the first array.

    • removeItem

      public static <T> T[] removeItem(T[] array, int pos)

    • getArraySubset

      public static <T> T[] getArraySubset(T[] array, int start, int end)

    • toArray

      public static <T> T[] toArray(Class<T> classToCastTo, Collection<?> c)
      Convert Collection to a Java (typed) array [].
      Type Parameters:
      T - Type of the array
      Parameters:
      classToCastTo - array type (Object[], Person[], etc.)
      c - Collection containing items to be placed into the array.
      Returns:
      Array of the type (T) containing the items from collection 'c'.