Class ArrayUtils


  • public class ArrayUtils
    extends java.lang.Object
    Utility methods for working with arrays.
    Since:
    1.0
    • Constructor Summary

      Constructors 
      Constructor Description
      ArrayUtils()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static byte[] concat​(byte[] a, byte... b)
      Concatenate two byte arrays.
      static <T> T[] concat​(T[] a, T... b)
      Concatenate two arrays.
      static boolean isEmpty​(java.lang.Object[] array)
      Whether the given array is empty.
      static boolean isNotEmpty​(java.lang.Object[] array)
      Whether the given array is not empty.
      static <T> java.util.Iterator<T> iterator​(T... array)
      Produce an iterator for the given array.
      static <T> java.util.Iterator<T> reverseIterator​(T... array)
      Produce an iterator for the given array.
      static <T> T[] toArray​(java.util.Collection<T> collection, java.lang.Class<T> arrayItemClass)
      Returns an array containing all of the elements in this collection, using the item class.
      static <T> T[] toArray​(java.util.Collection<T> collection, java.util.function.IntFunction<T[]> createArrayFn)
      Returns an array containing all of the elements in this collection, using the provided generator function to allocate the returned array.
      static java.lang.Object toPrimitiveArray​(java.lang.Object[] wrapperArray)
      Converts a primitive wrapper array to the equivalent primitive array such as Integer[] to int[].
      static java.lang.String toString​(java.lang.Object[] array)
      Produce a string representation of the given array.
      static java.lang.String toString​(java.lang.String delimiter, java.lang.Object[] array)
      Produce a string representation of the given array.
      static java.lang.Object[] toWrapperArray​(java.lang.Object primitiveArray)
      Converts a primitive array to the equivalent wrapper such as int[] to Integer[].
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • EMPTY_OBJECT_ARRAY

        public static final java.lang.Object[] EMPTY_OBJECT_ARRAY
        An empty object array.
      • EMPTY_BOOLEAN_ARRAY

        public static final boolean[] EMPTY_BOOLEAN_ARRAY
        An empty boolean array.
      • EMPTY_BYTE_ARRAY

        public static final byte[] EMPTY_BYTE_ARRAY
        An empty byte array.
      • EMPTY_CHAR_ARRAY

        public static final char[] EMPTY_CHAR_ARRAY
        An empty char array.
      • EMPTY_INT_ARRAY

        public static final int[] EMPTY_INT_ARRAY
        An empty int array.
      • EMPTY_DOUBLE_ARRAY

        public static final double[] EMPTY_DOUBLE_ARRAY
        An empty double array.
      • EMPTY_LONG_ARRAY

        public static final long[] EMPTY_LONG_ARRAY
        An empty long array.
      • EMPTY_FLOAT_ARRAY

        public static final float[] EMPTY_FLOAT_ARRAY
        An empty float array.
      • EMPTY_SHORT_ARRAY

        public static final short[] EMPTY_SHORT_ARRAY
        An empty short array.
    • Constructor Detail

      • ArrayUtils

        public ArrayUtils()
    • Method Detail

      • concat

        public static <T> T[] concat​(T[] a,
                                     T... b)
        Concatenate two arrays.
        Type Parameters:
        T - The array type
        Parameters:
        a - The first array
        b - The second array
        Returns:
        The concatenated array
      • concat

        public static byte[] concat​(byte[] a,
                                    byte... b)
        Concatenate two byte arrays.
        Parameters:
        a - The first array
        b - The second array
        Returns:
        The concatenated array
      • isEmpty

        public static boolean isEmpty​(java.lang.Object[] array)
        Whether the given array is empty.
        Parameters:
        array - The array
        Returns:
        True if it is
      • isNotEmpty

        public static boolean isNotEmpty​(java.lang.Object[] array)
        Whether the given array is not empty.
        Parameters:
        array - The array
        Returns:
        True if it is
      • toString

        public static java.lang.String toString​(@Nullable
                                                java.lang.Object[] array)
        Produce a string representation of the given array.
        Parameters:
        array - The array
        Returns:
        The string representation
      • toString

        public static java.lang.String toString​(java.lang.String delimiter,
                                                @Nullable
                                                java.lang.Object[] array)
        Produce a string representation of the given array.
        Parameters:
        delimiter - The delimiter
        array - The array
        Returns:
        The string representation
      • iterator

        public static <T> java.util.Iterator<T> iterator​(T... array)
        Produce an iterator for the given array.
        Type Parameters:
        T - The array type
        Parameters:
        array - The array
        Returns:
        The iterator
      • reverseIterator

        public static <T> java.util.Iterator<T> reverseIterator​(T... array)
        Produce an iterator for the given array.
        Type Parameters:
        T - The array type
        Parameters:
        array - The array
        Returns:
        The iterator
      • toArray

        public static <T> T[] toArray​(java.util.Collection<T> collection,
                                      java.util.function.IntFunction<T[]> createArrayFn)
        Returns an array containing all of the elements in this collection, using the provided generator function to allocate the returned array.
        Type Parameters:
        T - The type of the array
        Parameters:
        collection - The collection
        createArrayFn - The function to create the array
        Returns:
        The array
      • toArray

        public static <T> T[] toArray​(java.util.Collection<T> collection,
                                      java.lang.Class<T> arrayItemClass)
        Returns an array containing all of the elements in this collection, using the item class.
        Type Parameters:
        T - The type of the array
        Parameters:
        collection - The collection
        arrayItemClass - The array item class
        Returns:
        The array
        Since:
        3.0
      • toWrapperArray

        public static java.lang.Object[] toWrapperArray​(java.lang.Object primitiveArray)
        Converts a primitive array to the equivalent wrapper such as int[] to Integer[].
        Parameters:
        primitiveArray - The primitive array
        Returns:
        The primitive array wrapper.
        Since:
        3.0.0
      • toPrimitiveArray

        public static java.lang.Object toPrimitiveArray​(java.lang.Object[] wrapperArray)
        Converts a primitive wrapper array to the equivalent primitive array such as Integer[] to int[].
        Parameters:
        wrapperArray - The wrapper array
        Returns:
        The primitive array.
        Since:
        3.0.0