Class ArrayUtil


  • public class ArrayUtil
    extends java.lang.Object
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static <T> T[] add​(T[] array, T element)
      Copies the given array and adds the given element at the end of the new array.
      static int[] toIntArray​(java.util.List<java.lang.Integer> ints)  
      static java.util.List<java.lang.Integer> toIntList​(int[] ints)  
      static long[] toLongArray​(java.util.List<java.lang.Long> longs)  
      static java.util.List<java.lang.Long> toLongList​(long[] longs)  
      static boolean[] toPrimitive​(java.lang.Boolean[] array)
      Converts an array of object Booleans to primitives.
      static byte[] toPrimitive​(java.lang.Byte[] array)
      Converts an array of object Bytes to primitives.
      static double[] toPrimitive​(java.lang.Double[] array)
      Converts an array of object Doubles to primitives.
      static float[] toPrimitive​(java.lang.Float[] array)
      Converts an array of object Floats to primitives.
      static int[] toPrimitive​(java.lang.Integer[] array)
      Converts an array of object Integers to primitives.
      static long[] toPrimitive​(java.lang.Long[] array)
      Converts an array of object Longs to primitives.
      static short[] toPrimitive​(java.lang.Short[] array)
      Converts an array of object Shorts to primitives.
      • Methods inherited from class java.lang.Object

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

      • EMPTY_BOOLEAN_ARRAY

        public static final boolean[] EMPTY_BOOLEAN_ARRAY
      • EMPTY_BYTE_ARRAY

        public static final byte[] EMPTY_BYTE_ARRAY
      • EMPTY_SHORT_ARRAY

        public static final short[] EMPTY_SHORT_ARRAY
      • EMPTY_INT_ARRAY

        public static final int[] EMPTY_INT_ARRAY
      • EMPTY_LONG_ARRAY

        public static final long[] EMPTY_LONG_ARRAY
      • EMPTY_FLOAT_ARRAY

        public static final float[] EMPTY_FLOAT_ARRAY
      • EMPTY_DOUBLE_ARRAY

        public static final double[] EMPTY_DOUBLE_ARRAY
    • Method Detail

      • toIntList

        public static java.util.List<java.lang.Integer> toIntList​(int[] ints)
      • toIntArray

        public static int[] toIntArray​(java.util.List<java.lang.Integer> ints)
      • toLongList

        public static java.util.List<java.lang.Long> toLongList​(long[] longs)
      • toLongArray

        public static long[] toLongArray​(java.util.List<java.lang.Long> longs)
      • toPrimitive

        public static boolean[] toPrimitive​(java.lang.Boolean[] array)
        Converts an array of object Booleans to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Boolean array, may be null
        Returns:
        a boolean array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • toPrimitive

        public static byte[] toPrimitive​(java.lang.Byte[] array)
        Converts an array of object Bytes to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Byte array, may be null
        Returns:
        a byte array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • toPrimitive

        public static short[] toPrimitive​(java.lang.Short[] array)
        Converts an array of object Shorts to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Short array, may be null
        Returns:
        a byte array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • toPrimitive

        public static int[] toPrimitive​(java.lang.Integer[] array)
        Converts an array of object Integers to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Integer array, may be null
        Returns:
        an int array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • toPrimitive

        public static long[] toPrimitive​(java.lang.Long[] array)
        Converts an array of object Longs to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Long array, may be null
        Returns:
        a long array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • toPrimitive

        public static float[] toPrimitive​(java.lang.Float[] array)
        Converts an array of object Floats to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Float array, may be null
        Returns:
        a float array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • toPrimitive

        public static double[] toPrimitive​(java.lang.Double[] array)
        Converts an array of object Doubles to primitives.

        This method returns null for a null input array.

        This code is borrowed from `org.apache.commons:commons-lang3`.

        Parameters:
        array - a Double array, may be null
        Returns:
        a double array, null if null array input
        Throws:
        java.lang.NullPointerException - if array content is null
      • add

        public static <T> T[] add​(T[] array,
                                  T element)
        Copies the given array and adds the given element at the end of the new array.

        The new array contains the same elements of the input array plus the given element in the last position. The component type of the new array is the same as that of the input array.

        If the input array is null, a new one element array is returned whose component type is the same as the element, unless the element itself is null, in which case the return type is Object[]

         ArrayUtils.add(null, null)      = IllegalArgumentException
         ArrayUtils.add(null, "a")       = ["a"]
         ArrayUtils.add(["a"], null)     = ["a", null]
         ArrayUtils.add(["a"], "b")      = ["a", "b"]
         ArrayUtils.add(["a", "b"], "c") = ["a", "b", "c"]
         
        This code is borrowed from `org.apache.commons:commons-lang3`.
        Type Parameters:
        T - the component type of the array
        Parameters:
        array - the array to "add" the element to, may be null
        element - the object to add, may be null
        Returns:
        A new array containing the existing elements plus the new element The returned array type will be that of the input array (unless null), in which case it will have the same type as the element. If both are null, an IllegalArgumentException is thrown
        Throws:
        java.lang.IllegalArgumentException - if both arguments are null
        Since:
        2.1