Package com.android.internal.util

Class ArrayUtils

  • public class ArrayUtils
extends java.lang.Object
    Static utility methods for arrays that aren't already included in Arrays.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.io.File[] EMPTY_FILE  

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static <T> android.util.ArraySet<T> add​(android.util.ArraySet<T> cur, T val)  
      static <T> java.util.ArrayList<T> add​(java.util.ArrayList<T> cur, int index, T val)  
      static <T> java.util.ArrayList<T> add​(java.util.ArrayList<T> cur, T val)  
      static <T> android.util.ArraySet<T> addAll​(android.util.ArraySet<T> cur, java.util.Collection<T> val)
      Similar to Set.addAll(Collection)}, but with support for set values of null.
      static <T> T[] appendElement​(java.lang.Class<T> kind, T[] array, T element)
      Adds value to given array if not already present, providing set-like behavior.
      static <T> T[] appendElement​(java.lang.Class<T> kind, T[] array, T element, boolean allowDuplicates)
      Adds value to given array.
      static int[] appendInt​(int[] cur, int val)
      Adds value to given array if not already present, providing set-like behavior.
      static int[] appendInt​(int[] cur, int val, boolean allowDuplicates)
      Adds value to given array.
      static long[] appendLong​(long[] cur, long val)
      Adds value to given array if not already present, providing set-like behavior.
      static long[] appendLong​(long[] cur, long val, boolean allowDuplicates)
      Adds value to given array if not already present, providing set-like behavior.
      static void checkBounds​(int len, int index)
      Throws ArrayIndexOutOfBoundsException if the index is out of bounds.
      static long[] cloneOrNull​(long[] array)  
      static <T> android.util.ArraySet<T> cloneOrNull​(android.util.ArraySet<T> array)  
      static <T> T[] cloneOrNull​(T[] array)
      Clones an array or returns null if the array is null.
      static byte[] concat​(byte[]... arrays)
      Returns the concatenation of the given byte arrays.
      static <T> T[] concat​(java.lang.Class<T> kind, T[]... arrays)
      Returns the concatenation of the given arrays.
      static boolean contains​(char[] array, char value)  
      static boolean contains​(int[] array, int value)  
      static boolean contains​(long[] array, long value)  
      static <T> boolean contains​(java.util.Collection<T> cur, T val)  
      static <T> boolean contains​(T[] array, T value)
      Checks that value is present as at least one of the elements of the array.
      static <T> boolean containsAll​(char[] array, char[] check)
      Test if all check items are contained in array.
      static <T> boolean containsAll​(T[] array, T[] check)
      Test if all check items are contained in array.
      static <T> boolean containsAny​(T[] array, T[] check)
      Test if any check items are contained in array.
      static int[] convertToIntArray​(android.util.ArraySet<java.lang.Integer> set)  
      static int[] convertToIntArray​(java.util.List<java.lang.Integer> list)
      Deprecated.
      use IntArray instead
      static long[] convertToLongArray​(int[] intArray)  
      static java.lang.String deepToString​(java.lang.Object value)  
      static int[] defeatNullable​(int[] val)  
      static java.io.File[] defeatNullable​(java.io.File[] val)  
      static java.lang.String[] defeatNullable​(java.lang.String[] val)  
      static <T> T[] emptyArray​(java.lang.Class<T> kind)
      Returns an empty array of the specified type.
      static <T> T[] emptyIfNull​(T[] items, java.lang.Class<T> kind)
      Returns the same array or an empty one if it's null.
      static boolean equals​(byte[] array1, byte[] array2, int length)
      Checks if the beginnings of two byte arrays are equal.
      static <T> T[] filter​(T[] items, java.util.function.IntFunction<T[]> arrayConstructor, java.util.function.Predicate<T> predicate)
      Returns an array containing elements from the given one that match the given predicate.
      static <T> T[] filterNotNull​(T[] val, java.util.function.IntFunction<T[]> arrayConstructor)
      Returns an array with values from val minus null values
      static <T> T find​(T[] items, java.util.function.Predicate<T> predicate)
      Returns the first element from the array for which condition predicate is true, or null if there is no such element
      static <T> T firstOrNull​(T[] items)  
      static <T> T getOrNull​(T[] items, int i)
      Returns the i-th item in items, if it exists and items is not null, otherwise returns null.
      static <T> int indexOf​(T[] array, T value)
      Return first index of value in array, or -1 if not found.
      static boolean isEmpty​(boolean[] array)
      Checks if given array is null or has zero elements.
      static boolean isEmpty​(byte[] array)
      Checks if given array is null or has zero elements.
      static boolean isEmpty​(int[] array)
      Checks if given array is null or has zero elements.
      static boolean isEmpty​(long[] array)
      Checks if given array is null or has zero elements.
      static boolean isEmpty​(java.util.Collection<?> array)
      Checks if given array is null or has zero elements.
      static boolean isEmpty​(java.util.Map<?,​?> map)
      Checks if given map is null or has zero elements.
      static <T> boolean isEmpty​(T[] array)
      Checks if given array is null or has zero elements.
      static <T> T[] newUnpaddedArray​(java.lang.Class<T> clazz, int minLen)  
      static boolean[] newUnpaddedBooleanArray​(int minLen)  
      static byte[] newUnpaddedByteArray​(int minLen)  
      static char[] newUnpaddedCharArray​(int minLen)  
      static float[] newUnpaddedFloatArray​(int minLen)  
      static int[] newUnpaddedIntArray​(int minLen)  
      static long[] newUnpaddedLongArray​(int minLen)  
      static java.lang.Object[] newUnpaddedObjectArray​(int minLen)  
      static <T> boolean referenceEquals​(java.util.ArrayList<T> a, java.util.ArrayList<T> b)
      Returns true if the two ArrayLists are equal with respect to the objects they contain.
      static <T> android.util.ArraySet<T> remove​(android.util.ArraySet<T> cur, T val)  
      static <T> java.util.ArrayList<T> remove​(java.util.ArrayList<T> cur, T val)  
      static <T> T[] removeElement​(java.lang.Class<T> kind, T[] array, T element)
      Removes value from given array if present, providing set-like behavior.
      static int[] removeInt​(int[] cur, int val)
      Removes value from given array if present, providing set-like behavior.
      static long[] removeLong​(long[] cur, long val)
      Removes value from given array if present, providing set-like behavior.
      static java.lang.String[] removeString​(java.lang.String[] cur, java.lang.String val)
      Removes value from given array if present, providing set-like behavior.
      static int size​(java.lang.Object[] array)
      Length of the given array or 0 if it's null.
      static int size​(java.util.Collection<?> collection)
      Length of the given collection or 0 if it's null.
      static int size​(java.util.Map<?,​?> map)
      Length of the given map or 0 if it's null.
      static boolean startsWith​(byte[] cur, byte[] val)  
      static void throwsIfOutOfBounds​(int len, int offset, int count)
      Throws ArrayIndexOutOfBoundsException if the range is out of bounds.
      static <T> java.util.List<T> toList​(T[] array)
      Creates a List from an array.
      static long total​(long[] array)  
      static <T> T[] trimToSize​(T[] array, int size)  
      static <T> int unstableRemoveIf​(java.util.ArrayList<T> collection, java.util.function.Predicate<T> predicate)
      Removes elements that match the predicate in an efficient way that alters the order of elements in the collection.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • EMPTY_FILE

        public static final java.io.File[] EMPTY_FILE

    • Method Detail

      • newUnpaddedByteArray

        public static byte[] newUnpaddedByteArray​(int minLen)

      • newUnpaddedCharArray

        public static char[] newUnpaddedCharArray​(int minLen)

      • newUnpaddedIntArray

        public static int[] newUnpaddedIntArray​(int minLen)

      • newUnpaddedBooleanArray

        public static boolean[] newUnpaddedBooleanArray​(int minLen)

      • newUnpaddedLongArray

        public static long[] newUnpaddedLongArray​(int minLen)

      • newUnpaddedFloatArray

        public static float[] newUnpaddedFloatArray​(int minLen)

      • newUnpaddedObjectArray

        public static java.lang.Object[] newUnpaddedObjectArray​(int minLen)

      • newUnpaddedArray

        public static <T> T[] newUnpaddedArray​(java.lang.Class<T> clazz,
                                       int minLen)

      • equals

        public static boolean equals​(byte[] array1,
                             byte[] array2,
                             int length)
        Checks if the beginnings of two byte arrays are equal.
        Parameters:
        array1 - the first byte array
        array2 - the second byte array
        length - the number of bytes to check
        Returns:
        true if they're equal, false otherwise

      • emptyArray

        public static <T> T[] emptyArray​(java.lang.Class<T> kind)
        Returns an empty array of the specified type. The intent is that it will return the same empty array every time to avoid reallocation, although this is not guaranteed.

      • emptyIfNull

        public static <T> T[] emptyIfNull​(T[] items,
                                  java.lang.Class<T> kind)
        Returns the same array or an empty one if it's null.

      • isEmpty

        public static boolean isEmpty​(java.util.Collection<?> array)
        Checks if given array is null or has zero elements.

      • isEmpty

        public static boolean isEmpty​(java.util.Map<?,​?> map)
        Checks if given map is null or has zero elements.

      • isEmpty

        public static <T> boolean isEmpty​(T[] array)
        Checks if given array is null or has zero elements.

      • isEmpty

        public static boolean isEmpty​(int[] array)
        Checks if given array is null or has zero elements.

      • isEmpty

        public static boolean isEmpty​(long[] array)
        Checks if given array is null or has zero elements.

      • isEmpty

        public static boolean isEmpty​(byte[] array)
        Checks if given array is null or has zero elements.

      • isEmpty

        public static boolean isEmpty​(boolean[] array)
        Checks if given array is null or has zero elements.

      • size

        public static int size​(java.lang.Object[] array)
        Length of the given array or 0 if it's null.

      • size

        public static int size​(java.util.Collection<?> collection)
        Length of the given collection or 0 if it's null.

      • size

        public static int size​(java.util.Map<?,​?> map)
        Length of the given map or 0 if it's null.

      • contains

        public static <T> boolean contains​(T[] array,
                                   T value)
        Checks that value is present as at least one of the elements of the array.
        Parameters:
        array - the array to check in
        value - the value to check for
        Returns:
        true if the value is present in the array

      • indexOf

        public static <T> int indexOf​(T[] array,
                              T value)
        Return first index of value in array, or -1 if not found.

      • containsAll

        public static <T> boolean containsAll​(T[] array,
                                      T[] check)
        Test if all check items are contained in array.

      • containsAny

        public static <T> boolean containsAny​(T[] array,
                                      T[] check)
        Test if any check items are contained in array.

      • contains

        public static boolean contains​(int[] array,
                               int value)

      • contains

        public static boolean contains​(long[] array,
                               long value)

      • contains

        public static boolean contains​(char[] array,
                               char value)

      • containsAll

        public static <T> boolean containsAll​(char[] array,
                                      char[] check)
        Test if all check items are contained in array.

      • total

        public static long total​(long[] array)

      • convertToIntArray

        @Deprecated
public static int[] convertToIntArray​(java.util.List<java.lang.Integer> list)
        Deprecated.
        use IntArray instead

      • convertToIntArray

        public static int[] convertToIntArray​(android.util.ArraySet<java.lang.Integer> set)

      • convertToLongArray

        public static long[] convertToLongArray​(int[] intArray)

      • concat

        public static <T> T[] concat​(java.lang.Class<T> kind,
                             T[]... arrays)
        Returns the concatenation of the given arrays. Only works for object arrays, not for primitive arrays. See concat(byte[]...) for a variant that works on byte arrays.
        Type Parameters:
        T - The class of the array elements (inferred from kind).
        Parameters:
        kind - The class of the array elements
        arrays - The arrays to concatenate. Null arrays are treated as empty.
        Returns:
        A single array containing all the elements of the parameter arrays.

      • concat

        public static byte[] concat​(byte[]... arrays)
        Returns the concatenation of the given byte arrays. Null arrays are treated as empty.

      • appendElement

        public static <T> T[] appendElement​(java.lang.Class<T> kind,
                                    T[] array,
                                    T element)
        Adds value to given array if not already present, providing set-like behavior.

      • appendElement

        public static <T> T[] appendElement​(java.lang.Class<T> kind,
                                    T[] array,
                                    T element,
                                    boolean allowDuplicates)
        Adds value to given array.

      • removeElement

        public static <T> T[] removeElement​(java.lang.Class<T> kind,
                                    T[] array,
                                    T element)
        Removes value from given array if present, providing set-like behavior.

      • appendInt

        public static int[] appendInt​(int[] cur,
                              int val,
                              boolean allowDuplicates)
        Adds value to given array.

      • appendInt

        public static int[] appendInt​(int[] cur,
                              int val)
        Adds value to given array if not already present, providing set-like behavior.

      • removeInt

        public static int[] removeInt​(int[] cur,
                              int val)
        Removes value from given array if present, providing set-like behavior.

      • removeString

        public static java.lang.String[] removeString​(java.lang.String[] cur,
                                              java.lang.String val)
        Removes value from given array if present, providing set-like behavior.

      • appendLong

        public static long[] appendLong​(long[] cur,
                                long val,
                                boolean allowDuplicates)
        Adds value to given array if not already present, providing set-like behavior.

      • appendLong

        public static long[] appendLong​(long[] cur,
                                long val)
        Adds value to given array if not already present, providing set-like behavior.

      • removeLong

        public static long[] removeLong​(long[] cur,
                                long val)
        Removes value from given array if present, providing set-like behavior.

      • cloneOrNull

        public static long[] cloneOrNull​(long[] array)

      • cloneOrNull

        public static <T> T[] cloneOrNull​(T[] array)
        Clones an array or returns null if the array is null.

      • cloneOrNull

        public static <T> android.util.ArraySet<T> cloneOrNull​(android.util.ArraySet<T> array)

      • add

        public static <T> android.util.ArraySet<T> add​(android.util.ArraySet<T> cur,
                                               T val)

      • addAll

        public static <T> android.util.ArraySet<T> addAll​(android.util.ArraySet<T> cur,
                                                  java.util.Collection<T> val)
        Similar to Set.addAll(Collection)}, but with support for set values of null.

      • remove

        public static <T> android.util.ArraySet<T> remove​(android.util.ArraySet<T> cur,
                                                  T val)

      • add

        public static <T> java.util.ArrayList<T> add​(java.util.ArrayList<T> cur,
                                             T val)

      • add

        public static <T> java.util.ArrayList<T> add​(java.util.ArrayList<T> cur,
                                             int index,
                                             T val)

      • remove

        public static <T> java.util.ArrayList<T> remove​(java.util.ArrayList<T> cur,
                                                T val)

      • contains

        public static <T> boolean contains​(java.util.Collection<T> cur,
                                   T val)

      • trimToSize

        public static <T> T[] trimToSize​(T[] array,
                                 int size)

      • referenceEquals

        public static <T> boolean referenceEquals​(java.util.ArrayList<T> a,
                                          java.util.ArrayList<T> b)
        Returns true if the two ArrayLists are equal with respect to the objects they contain. The objects must be in the same order and be reference equal (== not .equals()).

      • unstableRemoveIf

        public static <T> int unstableRemoveIf​(java.util.ArrayList<T> collection,
                                       java.util.function.Predicate<T> predicate)
        Removes elements that match the predicate in an efficient way that alters the order of elements in the collection. This should only be used if order is not important.
        Parameters:
        collection - The ArrayList from which to remove elements.
        predicate - The predicate that each element is tested against.
        Returns:
        the number of elements removed.

      • defeatNullable

        public static int[] defeatNullable​(int[] val)

      • defeatNullable

        public static java.lang.String[] defeatNullable​(java.lang.String[] val)

      • defeatNullable

        public static java.io.File[] defeatNullable​(java.io.File[] val)

      • checkBounds

        public static void checkBounds​(int len,
                               int index)
        Throws ArrayIndexOutOfBoundsException if the index is out of bounds.
        Parameters:
        len - length of the array. Must be non-negative
        index - the index to check
        Throws:
        java.lang.ArrayIndexOutOfBoundsException - if the index is out of bounds of the array

      • throwsIfOutOfBounds

        public static void throwsIfOutOfBounds​(int len,
                                       int offset,
                                       int count)
        Throws ArrayIndexOutOfBoundsException if the range is out of bounds.
        Parameters:
        len - length of the array. Must be non-negative
        offset - start index of the range. Must be non-negative
        count - length of the range. Must be non-negative
        Throws:
        java.lang.ArrayIndexOutOfBoundsException - if the range from offset with length count is out of bounds of the array

      • filterNotNull

        public static <T> T[] filterNotNull​(T[] val,
                                    java.util.function.IntFunction<T[]> arrayConstructor)
        Returns an array with values from val minus null values
        Parameters:
        arrayConstructor - typically T[]::new e.g. String[]::new

      • filter

        public static <T> T[] filter​(T[] items,
                             java.util.function.IntFunction<T[]> arrayConstructor,
                             java.util.function.Predicate<T> predicate)
        Returns an array containing elements from the given one that match the given predicate. The returned array may, in some cases, be the reference to the input array.

      • startsWith

        public static boolean startsWith​(byte[] cur,
                                 byte[] val)

      • find

        public static <T> T find​(T[] items,
                         java.util.function.Predicate<T> predicate)
        Returns the first element from the array for which condition predicate is true, or null if there is no such element

      • deepToString

        public static java.lang.String deepToString​(java.lang.Object value)

      • getOrNull

        public static <T> T getOrNull​(T[] items,
                              int i)
        Returns the i-th item in items, if it exists and items is not null, otherwise returns null.

      • firstOrNull

        public static <T> T firstOrNull​(T[] items)

      • toList

        public static <T> java.util.List<T> toList​(T[] array)
        Creates a List from an array. Different from Arrays.asList(Object[]) as that will use the parameter as the backing array, meaning changes are not isolated.