/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ package java.util; import java.io.Serializable; import java.lang.reflect.Array; /** * {@code Arrays} contains static methods which operate on arrays. * * @since 1.2 */ public class Arrays { private static class ArrayList<E> extends AbstractList<E> implements List<E>, Serializable, RandomAccess { private static final long serialVersionUID = -2764017481108945198L; private final E[] a; ArrayList(E[] storage) { if (storage == null) { throw new NullPointerException("storage == null"); } a = storage; } @Override public boolean contains(Object object) { if (object != null) { for (E element : a) { if (object.equals(element)) { return true; } } } else { for (E element : a) { if (element == null) { return true; } } } return false; } @Override public E get(int location) { try { return a[location]; } catch (ArrayIndexOutOfBoundsException e) { throw java.util.ArrayList.throwIndexOutOfBoundsException(location, a.length); } } @Override public int indexOf(Object object) { if (object != null) { for (int i = 0; i < a.length; i++) { if (object.equals(a[i])) { return i; } } } else { for (int i = 0; i < a.length; i++) { if (a[i] == null) { return i; } } } return -1; } @Override public int lastIndexOf(Object object) { if (object != null) { for (int i = a.length - 1; i >= 0; i--) { if (object.equals(a[i])) { return i; } } } else { for (int i = a.length - 1; i >= 0; i--) { if (a[i] == null) { return i; } } } return -1; } @Override public E set(int location, E object) { E result = a[location]; a[location] = object; return result; } @Override public int size() { return a.length; } @Override public Object[] toArray() { return a.clone(); } @Override @SuppressWarnings({"unchecked", "SuspiciousSystemArraycopy"}) public <T> T[] toArray(T[] contents) { int size = size(); if (size > contents.length) { Class<?> ct = contents.getClass().getComponentType(); contents = (T[]) Array.newInstance(ct, size); } System.arraycopy(a, 0, contents, 0, size); if (size < contents.length) { contents[size] = null; } return contents; } } private Arrays() { /* empty */ } /** * Returns a {@code List} of the objects in the specified array. The size of the * {@code List} cannot be modified, i.e. adding and removing are unsupported, but * the elements can be set. Setting an element modifies the underlying * array. * * @param array * the array. * @return a {@code List} of the elements of the specified array. */ @SafeVarargs public static <T> List<T> asList(T... array) { return new ArrayList<T>(array); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(byte[] array, byte value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(byte[] array, int startIndex, int endIndex, byte value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; byte midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(char[] array, char value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(char[] array, int startIndex, int endIndex, char value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; char midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(double[] array, double value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(double[] array, int startIndex, int endIndex, double value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; double midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else if (midVal != 0 && midVal == value) { return mid; // value found } else { // Either midVal and value are == 0 or at least one is NaN long midValBits = Double.doubleToLongBits(midVal); long valueBits = Double.doubleToLongBits(value); if (midValBits < valueBits) { lo = mid + 1; // (-0.0, 0.0) or (not NaN, NaN); midVal < val } else if (midValBits > valueBits) { hi = mid - 1; // (0.0, -0.0) or (NaN, not NaN); midVal > val } else { return mid; // bit patterns are equal; value found } } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(float[] array, float value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(float[] array, int startIndex, int endIndex, float value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; float midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else if (midVal != 0 && midVal == value) { return mid; // value found } else { // Either midVal and value are == 0 or at least one is NaN int midValBits = Float.floatToIntBits(midVal); int valueBits = Float.floatToIntBits(value); if (midValBits < valueBits) { lo = mid + 1; // (-0.0, 0.0) or (not NaN, NaN); midVal < val } else if (midValBits > valueBits) { hi = mid - 1; // (0.0, -0.0) or (NaN, not NaN); midVal > val } else { return mid; // bit patterns are equal; value found } } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(int[] array, int value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(int[] array, int startIndex, int endIndex, int value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; int midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(long[] array, long value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(long[] array, int startIndex, int endIndex, long value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; long midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws ClassCastException * if an element in the array or the search element does not * implement {@code Comparable}, or cannot be compared to each other. */ public static int binarySearch(Object[] array, Object value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws ClassCastException * if an element in the array or the search element does not * implement {@code Comparable}, or cannot be compared to each other. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(Object[] array, int startIndex, int endIndex, Object value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; @SuppressWarnings("unchecked") int midValCmp = ((Comparable) array[mid]).compareTo(value); if (midValCmp < 0) { lo = mid + 1; } else if (midValCmp > 0) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * using {@code comparator} to compare elements. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @param comparator the {@code Comparator} used to compare the elements. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws ClassCastException * if an element in the array or the search element does not * implement {@code Comparable}, or cannot be compared to each other. */ public static <T> int binarySearch(T[] array, T value, Comparator<? super T> comparator) { return binarySearch(array, 0, array.length, value, comparator); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive), * using {@code comparator} to compare elements. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @param comparator the {@code Comparator} used to compare the elements. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws ClassCastException * if an element in the array or the search element does not * implement {@code Comparable}, or cannot be compared to each other. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static <T> int binarySearch(T[] array, int startIndex, int endIndex, T value, Comparator<? super T> comparator) { if (comparator == null) { return binarySearch(array, startIndex, endIndex, value); } checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; int midValCmp = comparator.compare(array[mid], value); if (midValCmp < 0) { lo = mid + 1; } else if (midValCmp > 0) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}. * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. */ public static int binarySearch(short[] array, short value) { return binarySearch(array, 0, array.length, value); } /** * Performs a binary search for {@code value} in the ascending sorted array {@code array}, * in the range specified by fromIndex (inclusive) and toIndex (exclusive). * Searching in an unsorted array has an undefined result. It's also undefined which element * is found if there are multiple occurrences of the same element. * * @param array the sorted array to search. * @param startIndex the inclusive start index. * @param endIndex the exclusive start index. * @param value the element to find. * @return the non-negative index of the element, or a negative index which * is {@code -index - 1} where the element would be inserted. * @throws IllegalArgumentException if {@code startIndex > endIndex} * @throws ArrayIndexOutOfBoundsException if {@code startIndex < 0 || endIndex > array.length} * @since 1.6 */ public static int binarySearch(short[] array, int startIndex, int endIndex, short value) { checkBinarySearchBounds(startIndex, endIndex, array.length); int lo = startIndex; int hi = endIndex - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; short midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } private static void checkBinarySearchBounds(int startIndex, int endIndex, int length) { if (startIndex > endIndex) { throw new IllegalArgumentException(); } if (startIndex < 0 || endIndex > length) { throw new ArrayIndexOutOfBoundsException(); } } /** * Fills the specified array with the specified element. * * @param array * the {@code byte} array to fill. * @param value * the {@code byte} element. */ public static void fill(byte[] array, byte value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code byte} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code byte} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(byte[] array, int start, int end, byte value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code short} array to fill. * @param value * the {@code short} element. */ public static void fill(short[] array, short value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code short} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code short} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(short[] array, int start, int end, short value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code char} array to fill. * @param value * the {@code char} element. */ public static void fill(char[] array, char value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code char} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code char} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(char[] array, int start, int end, char value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code int} array to fill. * @param value * the {@code int} element. */ public static void fill(int[] array, int value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code int} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code int} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(int[] array, int start, int end, int value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code long} array to fill. * @param value * the {@code long} element. */ public static void fill(long[] array, long value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code long} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code long} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(long[] array, int start, int end, long value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code float} array to fill. * @param value * the {@code float} element. */ public static void fill(float[] array, float value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code float} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code float} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(float[] array, int start, int end, float value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code double} array to fill. * @param value * the {@code double} element. */ public static void fill(double[] array, double value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code double} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code double} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(double[] array, int start, int end, double value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code boolean} array to fill. * @param value * the {@code boolean} element. */ public static void fill(boolean[] array, boolean value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code boolean} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code boolean} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(boolean[] array, int start, int end, boolean value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Fills the specified array with the specified element. * * @param array * the {@code Object} array to fill. * @param value * the {@code Object} element. */ public static void fill(Object[] array, Object value) { for (int i = 0; i < array.length; i++) { array[i] = value; } } /** * Fills the specified range in the array with the specified element. * * @param array * the {@code Object} array to fill. * @param start * the first index to fill. * @param end * the last + 1 index to fill. * @param value * the {@code Object} element. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void fill(Object[] array, int start, int end, Object value) { Arrays.checkStartAndEnd(array.length, start, end); for (int i = start; i < end; i++) { array[i] = value; } } /** * Returns a hash code based on the contents of the given array. For any two * {@code boolean} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Boolean} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(boolean[] array) { if (array == null) { return 0; } int hashCode = 1; for (boolean element : array) { // 1231, 1237 are hash code values for boolean value hashCode = 31 * hashCode + (element ? 1231 : 1237); } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * not-null {@code int} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Integer} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(int[] array) { if (array == null) { return 0; } int hashCode = 1; for (int element : array) { // the hash code value for integer value is integer value itself hashCode = 31 * hashCode + element; } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * {@code short} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Short} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(short[] array) { if (array == null) { return 0; } int hashCode = 1; for (short element : array) { // the hash code value for short value is its integer value hashCode = 31 * hashCode + element; } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * {@code char} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Character} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(char[] array) { if (array == null) { return 0; } int hashCode = 1; for (char element : array) { // the hash code value for char value is its integer value hashCode = 31 * hashCode + element; } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * {@code byte} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Byte} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(byte[] array) { if (array == null) { return 0; } int hashCode = 1; for (byte element : array) { // the hash code value for byte value is its integer value hashCode = 31 * hashCode + element; } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * {@code long} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Long} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(long[] array) { if (array == null) { return 0; } int hashCode = 1; for (long elementValue : array) { /* * the hash code value for long value is (int) (value ^ (value >>> * 32)) */ hashCode = 31 * hashCode + (int) (elementValue ^ (elementValue >>> 32)); } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * {@code float} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Float} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(float[] array) { if (array == null) { return 0; } int hashCode = 1; for (float element : array) { /* * the hash code value for float value is * Float.floatToIntBits(value) */ hashCode = 31 * hashCode + Float.floatToIntBits(element); } return hashCode; } /** * Returns a hash code based on the contents of the given array. For any two * {@code double} arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the * {@link List#hashCode()} method which is invoked on a {@link List} * containing a sequence of {@link Double} instances representing the * elements of array in the same order. If the array is {@code null}, the return * value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(double[] array) { if (array == null) { return 0; } int hashCode = 1; for (double element : array) { long v = Double.doubleToLongBits(element); /* * the hash code value for double value is (int) (v ^ (v >>> 32)) * where v = Double.doubleToLongBits(value) */ hashCode = 31 * hashCode + (int) (v ^ (v >>> 32)); } return hashCode; } /** * Returns a hash code based on the contents of the given array. If the * array contains other arrays as its elements, the hash code is based on * their identities not their contents. So it is acceptable to invoke this * method on an array that contains itself as an element, either directly or * indirectly. * <p> * For any two arrays {@code a} and {@code b}, if * {@code Arrays.equals(a, b)} returns {@code true}, it means * that the return value of {@code Arrays.hashCode(a)} equals * {@code Arrays.hashCode(b)}. * <p> * The value returned by this method is the same value as the method * Arrays.asList(array).hashCode(). If the array is {@code null}, the return value * is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int hashCode(Object[] array) { if (array == null) { return 0; } int hashCode = 1; for (Object element : array) { int elementHashCode; if (element == null) { elementHashCode = 0; } else { elementHashCode = (element).hashCode(); } hashCode = 31 * hashCode + elementHashCode; } return hashCode; } /** * Returns a hash code based on the "deep contents" of the given array. If * the array contains other arrays as its elements, the hash code is based * on their contents not their identities. So it is not acceptable to invoke * this method on an array that contains itself as an element, either * directly or indirectly. * <p> * For any two arrays {@code a} and {@code b}, if * {@code Arrays.deepEquals(a, b)} returns {@code true}, it * means that the return value of {@code Arrays.deepHashCode(a)} equals * {@code Arrays.deepHashCode(b)}. * <p> * The computation of the value returned by this method is similar to that * of the value returned by {@link List#hashCode()} invoked on a * {@link List} containing a sequence of instances representing the * elements of array in the same order. The difference is: If an element e * of array is itself an array, its hash code is computed by calling the * appropriate overloading of {@code Arrays.hashCode(e)} if e is an array of a * primitive type, or by calling {@code Arrays.deepHashCode(e)} recursively if e is * an array of a reference type. The value returned by this method is the * same value as the method {@code Arrays.asList(array).hashCode()}. If the array is * {@code null}, the return value is 0. * * @param array * the array whose hash code to compute. * @return the hash code for {@code array}. */ public static int deepHashCode(Object[] array) { if (array == null) { return 0; } int hashCode = 1; for (Object element : array) { int elementHashCode = deepHashCodeElement(element); hashCode = 31 * hashCode + elementHashCode; } return hashCode; } private static int deepHashCodeElement(Object element) { Class<?> cl; if (element == null) { return 0; } cl = element.getClass().getComponentType(); if (cl == null) { return element.hashCode(); } /* * element is an array */ if (element instanceof Object[]) { return deepHashCode((Object[]) element); } else if (cl == int.class) { return hashCode((int[]) element); } else if (cl == char.class) { return hashCode((char[]) element); } else if (cl == boolean.class) { return hashCode((boolean[]) element); } else if (cl == byte.class) { return hashCode((byte[]) element); } else if (cl == long.class) { return hashCode((long[]) element); } else if (cl == float.class) { return hashCode((float[]) element); } else if (cl == double.class) { return hashCode((double[]) element); } else { return hashCode((short[]) element); } } /** * Compares the two arrays. * * @param array1 * the first {@code byte} array. * @param array2 * the second {@code byte} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. */ public static boolean equals(byte[] array1, byte[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (array1[i] != array2[i]) { return false; } } return true; } /** * Compares the two arrays. * * @param array1 * the first {@code short} array. * @param array2 * the second {@code short} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. */ public static boolean equals(short[] array1, short[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (array1[i] != array2[i]) { return false; } } return true; } /** * Compares the two arrays. * * @param array1 * the first {@code char} array. * @param array2 * the second {@code char} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. */ public static boolean equals(char[] array1, char[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (array1[i] != array2[i]) { return false; } } return true; } /** * Compares the two arrays. * * @param array1 * the first {@code int} array. * @param array2 * the second {@code int} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. */ public static boolean equals(int[] array1, int[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (array1[i] != array2[i]) { return false; } } return true; } /** * Compares the two arrays. * * @param array1 * the first {@code long} array. * @param array2 * the second {@code long} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. */ public static boolean equals(long[] array1, long[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (array1[i] != array2[i]) { return false; } } return true; } /** * Compares the two arrays. The values are compared in the same manner as * {@code Float.equals()}. * * @param array1 * the first {@code float} array. * @param array2 * the second {@code float} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. * @see Float#equals(Object) */ public static boolean equals(float[] array1, float[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (Float.floatToIntBits(array1[i]) != Float .floatToIntBits(array2[i])) { return false; } } return true; } /** * Compares the two arrays. The values are compared in the same manner as * {@code Double.equals()}. * * @param array1 * the first {@code double} array. * @param array2 * the second {@code double} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. * @see Double#equals(Object) */ public static boolean equals(double[] array1, double[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (Double.doubleToLongBits(array1[i]) != Double .doubleToLongBits(array2[i])) { return false; } } return true; } /** * Compares the two arrays. * * @param array1 * the first {@code boolean} array. * @param array2 * the second {@code boolean} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal, {@code false} otherwise. */ public static boolean equals(boolean[] array1, boolean[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { if (array1[i] != array2[i]) { return false; } } return true; } /** * Compares the two arrays. * * @param array1 * the first {@code Object} array. * @param array2 * the second {@code Object} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal according to {@code equals()}, {@code false} otherwise. */ public static boolean equals(Object[] array1, Object[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { Object e1 = array1[i], e2 = array2[i]; if (!(e1 == null ? e2 == null : e1.equals(e2))) { return false; } } return true; } /** * Returns {@code true} if the two given arrays are deeply equal to one another. * Unlike the method {@code equals(Object[] array1, Object[] array2)}, this method * is appropriate for use for nested arrays of arbitrary depth. * <p> * Two array references are considered deeply equal if they are both {@code null}, * or if they refer to arrays that have the same length and the elements at * each index in the two arrays are equal. * <p> * Two {@code null} elements {@code element1} and {@code element2} are possibly deeply equal if any * of the following conditions satisfied: * <p> * {@code element1} and {@code element2} are both arrays of object reference types, and * {@code Arrays.deepEquals(element1, element2)} would return {@code true}. * <p> * {@code element1} and {@code element2} are arrays of the same primitive type, and the * appropriate overloading of {@code Arrays.equals(element1, element2)} would return * {@code true}. * <p> * {@code element1 == element2} * <p> * {@code element1.equals(element2)} would return {@code true}. * <p> * Note that this definition permits {@code null} elements at any depth. * <p> * If either of the given arrays contain themselves as elements, the * behavior of this method is uncertain. * * @param array1 * the first {@code Object} array. * @param array2 * the second {@code Object} array. * @return {@code true} if both arrays are {@code null} or if the arrays have the * same length and the elements at each index in the two arrays are * equal according to {@code equals()}, {@code false} otherwise. */ public static boolean deepEquals(Object[] array1, Object[] array2) { if (array1 == array2) { return true; } if (array1 == null || array2 == null || array1.length != array2.length) { return false; } for (int i = 0; i < array1.length; i++) { Object e1 = array1[i], e2 = array2[i]; if (!deepEqualsElements(e1, e2)) { return false; } } return true; } private static boolean deepEqualsElements(Object e1, Object e2) { Class<?> cl1, cl2; if (e1 == e2) { return true; } if (e1 == null || e2 == null) { return false; } cl1 = e1.getClass().getComponentType(); cl2 = e2.getClass().getComponentType(); if (cl1 != cl2) { return false; } if (cl1 == null) { return e1.equals(e2); } /* * compare as arrays */ if (e1 instanceof Object[]) { return deepEquals((Object[]) e1, (Object[]) e2); } else if (cl1 == int.class) { return equals((int[]) e1, (int[]) e2); } else if (cl1 == char.class) { return equals((char[]) e1, (char[]) e2); } else if (cl1 == boolean.class) { return equals((boolean[]) e1, (boolean[]) e2); } else if (cl1 == byte.class) { return equals((byte[]) e1, (byte[]) e2); } else if (cl1 == long.class) { return equals((long[]) e1, (long[]) e2); } else if (cl1 == float.class) { return equals((float[]) e1, (float[]) e2); } else if (cl1 == double.class) { return equals((double[]) e1, (double[]) e2); } else { return equals((short[]) e1, (short[]) e2); } } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code byte} array to be sorted. */ public static void sort(byte[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. * * @param array * the {@code byte} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void sort(byte[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } /** * Checks that the range described by {@code offset} and {@code count} doesn't exceed * {@code arrayLength}. * * @hide */ public static void checkOffsetAndCount(int arrayLength, int offset, int count) { if ((offset | count) < 0 || offset > arrayLength || arrayLength - offset < count) { throw new ArrayIndexOutOfBoundsException(arrayLength, offset, count); } } /** * Checks that the range described by {@code start} and {@code end} doesn't exceed * {@code len}. * * @hide */ public static void checkStartAndEnd(int len, int start, int end) { if (start < 0 || end > len) { throw new ArrayIndexOutOfBoundsException("start < 0 || end > len." + " start=" + start + ", end=" + end + ", len=" + len); } if (start > end) { throw new IllegalArgumentException("start > end: " + start + " > " + end); } } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code char} array to be sorted. */ public static void sort(char[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. * * @param array * the {@code char} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void sort(char[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code double} array to be sorted. * @see #sort(double[], int, int) */ public static void sort(double[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. The * values are sorted according to the order imposed by {@code Double.compareTo()}. * * @param array * the {@code double} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. * @see Double#compareTo(Double) */ public static void sort(double[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code float} array to be sorted. * @see #sort(float[], int, int) */ public static void sort(float[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. The * values are sorted according to the order imposed by {@code Float.compareTo()}. * * @param array * the {@code float} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. * @see Float#compareTo(Float) */ public static void sort(float[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code int} array to be sorted. */ public static void sort(int[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. * * @param array * the {@code int} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void sort(int[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code long} array to be sorted. */ public static void sort(long[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. * * @param array * the {@code long} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void sort(long[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } /** * Sorts the specified array in ascending numerical order. * * @param array * the {@code short} array to be sorted. */ public static void sort(short[] array) { DualPivotQuicksort.sort(array); } /** * Sorts the specified range in the array in ascending numerical order. * * @param array * the {@code short} array to be sorted. * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void sort(short[] array, int start, int end) { DualPivotQuicksort.sort(array, start, end); } // BEGIN android-note /* * <p>If this platform has an optimizing VM, check whether ComparableTimSort * offers any performance benefit over TimSort in conjunction with a * comparator that returns: * {@code ((Comparable)first).compareTo(Second)}. * If not, you are better off deleting ComparableTimSort to eliminate the * code duplication. In other words, the commented out code below * is the preferable implementation for sorting arrays of Comparables if it * offers sufficient performance. */ // /** // * A comparator that implements the natural order of a group of // * mutually comparable elements. Using this comparator saves us // * from duplicating most of the code in this file (one version for // * Comparables, one for explicit comparators). // */ // private static final Comparator<Object> NATURAL_ORDER = new Comparator<Object>() { // @SuppressWarnings("unchecked") // public int compare(Object first, Object second) { // return ((Comparable<Object>)first).compareTo(second); // } // }; // // public static void sort(Object[] a) { // sort(a, 0, a.length, NATURAL_ORDER); // } // // public static void sort(Object[] a, int fromIndex, int toIndex) { // sort(a, fromIndex, toIndex, NATURAL_ORDER); // } // END android-note /** * Sorts the specified array in ascending natural order. * * @throws ClassCastException if any element does not implement {@code Comparable}, * or if {@code compareTo} throws for any pair of elements. */ public static void sort(Object[] array) { ComparableTimSort.sort(array); } /** * Sorts the specified range in the array in ascending natural order. * * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @throws ClassCastException if any element does not implement {@code Comparable}, * or if {@code compareTo} throws for any pair of elements. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static void sort(Object[] array, int start, int end) { ComparableTimSort.sort(array, start, end); } /** * Sorts the specified range in the array using the specified {@code Comparator}. * All elements must be comparable to each other without a * {@code ClassCastException} being thrown. * * @param start * the start index to sort. * @param end * the last + 1 index to sort. * @param comparator * the {@code Comparator}. * @throws ClassCastException * if elements in the array cannot be compared to each other * using the given {@code Comparator}. * @throws IllegalArgumentException * if {@code start > end}. * @throws ArrayIndexOutOfBoundsException * if {@code start < 0} or {@code end > array.length}. */ public static <T> void sort(T[] array, int start, int end, Comparator<? super T> comparator) { TimSort.sort(array, start, end, comparator); } /** * Sorts the specified array using the specified {@code Comparator}. All elements * must be comparable to each other without a {@code ClassCastException} being thrown. * * @throws ClassCastException * if elements in the array cannot be compared to each other * using the {@code Comparator}. */ public static <T> void sort(T[] array, Comparator<? super T> comparator) { TimSort.sort(array, comparator); } /** * Creates a {@code String} representation of the {@code boolean[]} passed. * The result is surrounded by brackets ({@code "[]"}), each * element is converted to a {@code String} via the * {@link String#valueOf(boolean)} and separated by {@code ", "}. * If the array is {@code null}, then {@code "null"} is returned. * * @param array * the {@code boolean} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(boolean[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 7); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code byte[]} passed. The * result is surrounded by brackets ({@code "[]"}), each element * is converted to a {@code String} via the {@link String#valueOf(int)} and * separated by {@code ", "}. If the array is {@code null}, then * {@code "null"} is returned. * * @param array * the {@code byte} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(byte[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 6); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code char[]} passed. The * result is surrounded by brackets ({@code "[]"}), each element * is converted to a {@code String} via the {@link String#valueOf(char)} and * separated by {@code ", "}. If the array is {@code null}, then * {@code "null"} is returned. * * @param array * the {@code char} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(char[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 3); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code double[]} passed. * The result is surrounded by brackets ({@code "[]"}), each * element is converted to a {@code String} via the * {@link String#valueOf(double)} and separated by {@code ", "}. * If the array is {@code null}, then {@code "null"} is returned. * * @param array * the {@code double} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(double[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 7); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code float[]} passed. * The result is surrounded by brackets ({@code "[]"}), each * element is converted to a {@code String} via the * {@link String#valueOf(float)} and separated by {@code ", "}. * If the array is {@code null}, then {@code "null"} is returned. * * @param array * the {@code float} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(float[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 7); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code int[]} passed. The * result is surrounded by brackets ({@code "[]"}), each element * is converted to a {@code String} via the {@link String#valueOf(int)} and * separated by {@code ", "}. If the array is {@code null}, then * {@code "null"} is returned. * * @param array * the {@code int} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(int[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 6); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code long[]} passed. The * result is surrounded by brackets ({@code "[]"}), each element * is converted to a {@code String} via the {@link String#valueOf(long)} and * separated by {@code ", "}. If the array is {@code null}, then * {@code "null"} is returned. * * @param array * the {@code long} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(long[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 6); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code short[]} passed. * The result is surrounded by brackets ({@code "[]"}), each * element is converted to a {@code String} via the * {@link String#valueOf(int)} and separated by {@code ", "}. If * the array is {@code null}, then {@code "null"} is returned. * * @param array * the {@code short} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(short[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 6); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a {@code String} representation of the {@code Object[]} passed. * The result is surrounded by brackets ({@code "[]"}), each * element is converted to a {@code String} via the * {@link String#valueOf(Object)} and separated by {@code ", "}. * If the array is {@code null}, then {@code "null"} is returned. * * @param array * the {@code Object} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String toString(Object[] array) { if (array == null) { return "null"; } if (array.length == 0) { return "[]"; } StringBuilder sb = new StringBuilder(array.length * 7); sb.append('['); sb.append(array[0]); for (int i = 1; i < array.length; i++) { sb.append(", "); sb.append(array[i]); } sb.append(']'); return sb.toString(); } /** * Creates a <i>"deep"</i> {@code String} representation of the * {@code Object[]} passed, such that if the array contains other arrays, * the {@code String} representation of those arrays is generated as well. * <p> * If any of the elements are primitive arrays, the generation is delegated * to the other {@code toString} methods in this class. If any element * contains a reference to the original array, then it will be represented * as {@code "[...]"}. If an element is an {@code Object[]}, then its * representation is generated by a recursive call to this method. All other * elements are converted via the {@link String#valueOf(Object)} method. * * @param array * the {@code Object} array to convert. * @return the {@code String} representation of {@code array}. * @since 1.5 */ public static String deepToString(Object[] array) { // Special case null to prevent NPE if (array == null) { return "null"; } // delegate this to the recursive method StringBuilder buf = new StringBuilder(array.length * 9); deepToStringImpl(array, new Object[] { array }, buf); return buf.toString(); } /** * Implementation method used by {@link #deepToString(Object[])}. * * @param array * the {@code Object[]} to dive into. * @param origArrays * the original {@code Object[]}; used to test for self * references. * @param sb * the {@code StringBuilder} instance to append to or * {@code null} one hasn't been created yet. * @return the result. * @see #deepToString(Object[]) */ private static void deepToStringImpl(Object[] array, Object[] origArrays, StringBuilder sb) { if (array == null) { sb.append("null"); return; } sb.append('['); for (int i = 0; i < array.length; i++) { if (i != 0) { sb.append(", "); } // establish current element Object elem = array[i]; if (elem == null) { // element is null sb.append("null"); } else { // get the Class of the current element Class<?> elemClass = elem.getClass(); if (elemClass.isArray()) { // element is an array type // get the declared Class of the array (element) Class<?> elemElemClass = elemClass.getComponentType(); if (elemElemClass.isPrimitive()) { // element is a primitive array if (boolean.class.equals(elemElemClass)) { sb.append(toString((boolean[]) elem)); } else if (byte.class.equals(elemElemClass)) { sb.append(toString((byte[]) elem)); } else if (char.class.equals(elemElemClass)) { sb.append(toString((char[]) elem)); } else if (double.class.equals(elemElemClass)) { sb.append(toString((double[]) elem)); } else if (float.class.equals(elemElemClass)) { sb.append(toString((float[]) elem)); } else if (int.class.equals(elemElemClass)) { sb.append(toString((int[]) elem)); } else if (long.class.equals(elemElemClass)) { sb.append(toString((long[]) elem)); } else if (short.class.equals(elemElemClass)) { sb.append(toString((short[]) elem)); } else { // no other possible primitives, so we assert that throw new AssertionError(); } } else { // element is an Object[], so we assert that // assert elem instanceof Object[]; if (deepToStringImplContains(origArrays, elem)) { sb.append("[...]"); } else { Object[] newArray = (Object[]) elem; Object[] newOrigArrays = new Object[origArrays.length + 1]; System.arraycopy(origArrays, 0, newOrigArrays, 0, origArrays.length); newOrigArrays[origArrays.length] = newArray; // make the recursive call to this method deepToStringImpl(newArray, newOrigArrays, sb); } } } else { // element is NOT an array, just an Object sb.append(array[i]); } } } sb.append(']'); } /** * Utility method used to assist the implementation of * {@link #deepToString(Object[])}. * * @param origArrays * An array of Object[] references. * @param array * An Object[] reference to look for in {@code origArrays}. * @return A value of {@code true} if {@code array} is an * element in {@code origArrays}. */ private static boolean deepToStringImplContains(Object[] origArrays, Object array) { if (origArrays == null || origArrays.length == 0) { return false; } for (Object element : origArrays) { if (element == array) { return true; } } return false; } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code false}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static boolean[] copyOf(boolean[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code (byte) 0}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static byte[] copyOf(byte[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code '\\u0000'}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static char[] copyOf(char[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code 0.0d}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static double[] copyOf(double[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code 0.0f}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static float[] copyOf(float[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code 0}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static int[] copyOf(int[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code 0L}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static long[] copyOf(long[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code (short) 0}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static short[] copyOf(short[] original, int newLength) { if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code null}. * * @param original the original array * @param newLength the length of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static <T> T[] copyOf(T[] original, int newLength) { if (original == null) { throw new NullPointerException("original == null"); } if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength); } /** * Copies {@code newLength} elements from {@code original} into a new array. * If {@code newLength} is greater than {@code original.length}, the result is padded * with the value {@code null}. * * @param original the original array * @param newLength the length of the new array * @param newType the class of the new array * @return the new array * @throws NegativeArraySizeException if {@code newLength < 0} * @throws NullPointerException if {@code original == null} * @throws ArrayStoreException if a value in {@code original} is incompatible with T * @since 1.6 */ public static <T, U> T[] copyOf(U[] original, int newLength, Class<? extends T[]> newType) { // We use the null pointer check in copyOfRange for exception priority compatibility. if (newLength < 0) { throw new NegativeArraySizeException(Integer.toString(newLength)); } return copyOfRange(original, 0, newLength, newType); } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code false}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static boolean[] copyOfRange(boolean[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); boolean[] result = new boolean[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code (byte) 0}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static byte[] copyOfRange(byte[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); byte[] result = new byte[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code '\\u0000'}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static char[] copyOfRange(char[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); char[] result = new char[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code 0.0d}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static double[] copyOfRange(double[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); double[] result = new double[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code 0.0f}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static float[] copyOfRange(float[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); float[] result = new float[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code 0}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static int[] copyOfRange(int[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); int[] result = new int[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code 0L}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static long[] copyOfRange(long[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); long[] result = new long[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code (short) 0}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ public static short[] copyOfRange(short[] original, int start, int end) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); short[] result = new short[resultLength]; System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code null}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @since 1.6 */ @SuppressWarnings("unchecked") public static <T> T[] copyOfRange(T[] original, int start, int end) { int originalLength = original.length; // For exception priority compatibility. if (start > end) { throw new IllegalArgumentException(); } if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); T[] result = (T[]) Array.newInstance(original.getClass().getComponentType(), resultLength); System.arraycopy(original, start, result, 0, copyLength); return result; } /** * Copies elements from {@code original} into a new array, from indexes start (inclusive) to * end (exclusive). The original order of elements is preserved. * If {@code end} is greater than {@code original.length}, the result is padded * with the value {@code null}. * * @param original the original array * @param start the start index, inclusive * @param end the end index, exclusive * @return the new array * @throws ArrayIndexOutOfBoundsException if {@code start < 0 || start > original.length} * @throws IllegalArgumentException if {@code start > end} * @throws NullPointerException if {@code original == null} * @throws ArrayStoreException if a value in {@code original} is incompatible with T * @since 1.6 */ @SuppressWarnings("unchecked") public static <T, U> T[] copyOfRange(U[] original, int start, int end, Class<? extends T[]> newType) { if (start > end) { throw new IllegalArgumentException(); } int originalLength = original.length; if (start < 0 || start > originalLength) { throw new ArrayIndexOutOfBoundsException(); } int resultLength = end - start; int copyLength = Math.min(resultLength, originalLength - start); T[] result = (T[]) Array.newInstance(newType.getComponentType(), resultLength); System.arraycopy(original, start, result, 0, copyLength); return result; } }