diff -r 5652acd48509 -r 42bc1e89134d emul/compact/src/main/java/java/util/Collections.java
--- a/emul/compact/src/main/java/java/util/Collections.java Mon Feb 25 19:00:08 2013 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,3953 +0,0 @@
-/*
- * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package java.util;
-import java.io.Serializable;
-import java.io.IOException;
-import java.lang.reflect.Array;
-
-/**
- * This class consists exclusively of static methods that operate on or return
- * collections. It contains polymorphic algorithms that operate on
- * collections, "wrappers", which return a new collection backed by a
- * specified collection, and a few other odds and ends.
- *
- * The methods of this class all throw a NullPointerException
- * if the collections or class objects provided to them are null.
- *
- *
The documentation for the polymorphic algorithms contained in this class
- * generally includes a brief description of the implementation. Such
- * descriptions should be regarded as implementation notes, rather than
- * parts of the specification. Implementors should feel free to
- * substitute other algorithms, so long as the specification itself is adhered
- * to. (For example, the algorithm used by sort does not have to be
- * a mergesort, but it does have to be stable.)
- *
- *
The "destructive" algorithms contained in this class, that is, the
- * algorithms that modify the collection on which they operate, are specified
- * to throw UnsupportedOperationException if the collection does not
- * support the appropriate mutation primitive(s), such as the set
- * method. These algorithms may, but are not required to, throw this
- * exception if an invocation would have no effect on the collection. For
- * example, invoking the sort method on an unmodifiable list that is
- * already sorted may or may not throw UnsupportedOperationException.
- *
- *
This class is a member of the
- *
- * Java Collections Framework.
- *
- * @author Josh Bloch
- * @author Neal Gafter
- * @see Collection
- * @see Set
- * @see List
- * @see Map
- * @since 1.2
- */
-
-public class Collections {
- // Suppresses default constructor, ensuring non-instantiability.
- private Collections() {
- }
-
- // Algorithms
-
- /*
- * Tuning parameters for algorithms - Many of the List algorithms have
- * two implementations, one of which is appropriate for RandomAccess
- * lists, the other for "sequential." Often, the random access variant
- * yields better performance on small sequential access lists. The
- * tuning parameters below determine the cutoff point for what constitutes
- * a "small" sequential access list for each algorithm. The values below
- * were empirically determined to work well for LinkedList. Hopefully
- * they should be reasonable for other sequential access List
- * implementations. Those doing performance work on this code would
- * do well to validate the values of these parameters from time to time.
- * (The first word of each tuning parameter name is the algorithm to which
- * it applies.)
- */
- private static final int BINARYSEARCH_THRESHOLD = 5000;
- private static final int REVERSE_THRESHOLD = 18;
- private static final int SHUFFLE_THRESHOLD = 5;
- private static final int FILL_THRESHOLD = 25;
- private static final int ROTATE_THRESHOLD = 100;
- private static final int COPY_THRESHOLD = 10;
- private static final int REPLACEALL_THRESHOLD = 11;
- private static final int INDEXOFSUBLIST_THRESHOLD = 35;
-
- /**
- * Sorts the specified list into ascending order, according to the
- * {@linkplain Comparable natural ordering} of its elements.
- * All elements in the list must implement the {@link Comparable}
- * interface. Furthermore, all elements in the list must be
- * mutually comparable (that is, {@code e1.compareTo(e2)}
- * must not throw a {@code ClassCastException} for any elements
- * {@code e1} and {@code e2} in the list).
- *
- *
This sort is guaranteed to be stable: equal elements will
- * not be reordered as a result of the sort.
- *
- *
The specified list must be modifiable, but need not be resizable.
- *
- *
Implementation note: This implementation is a stable, adaptive,
- * iterative mergesort that requires far fewer than n lg(n) comparisons
- * when the input array is partially sorted, while offering the
- * performance of a traditional mergesort when the input array is
- * randomly ordered. If the input array is nearly sorted, the
- * implementation requires approximately n comparisons. Temporary
- * storage requirements vary from a small constant for nearly sorted
- * input arrays to n/2 object references for randomly ordered input
- * arrays.
- *
- *
The implementation takes equal advantage of ascending and
- * descending order in its input array, and can take advantage of
- * ascending and descending order in different parts of the same
- * input array. It is well-suited to merging two or more sorted arrays:
- * simply concatenate the arrays and sort the resulting array.
- *
- *
The implementation was adapted from Tim Peters's list sort for Python
- * (
- * TimSort). It uses techiques from Peter McIlroy's "Optimistic
- * Sorting and Information Theoretic Complexity", in Proceedings of the
- * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
- * January 1993.
- *
- *
This implementation dumps the specified list into an array, sorts
- * the array, and iterates over the list resetting each element
- * from the corresponding position in the array. This avoids the
- * n2 log(n) performance that would result from attempting
- * to sort a linked list in place.
- *
- * @param list the list to be sorted.
- * @throws ClassCastException if the list contains elements that are not
- * mutually comparable (for example, strings and integers).
- * @throws UnsupportedOperationException if the specified list's
- * list-iterator does not support the {@code set} operation.
- * @throws IllegalArgumentException (optional) if the implementation
- * detects that the natural ordering of the list elements is
- * found to violate the {@link Comparable} contract
- */
- public static > void sort(List list) {
- Object[] a = list.toArray();
- Arrays.sort(a);
- ListIterator i = list.listIterator();
- for (int j=0; jmutually
- * comparable using the specified comparator (that is,
- * {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
- * for any elements {@code e1} and {@code e2} in the list).
- *
- * This sort is guaranteed to be stable: equal elements will
- * not be reordered as a result of the sort.
- *
- *
The specified list must be modifiable, but need not be resizable.
- *
- *
Implementation note: This implementation is a stable, adaptive,
- * iterative mergesort that requires far fewer than n lg(n) comparisons
- * when the input array is partially sorted, while offering the
- * performance of a traditional mergesort when the input array is
- * randomly ordered. If the input array is nearly sorted, the
- * implementation requires approximately n comparisons. Temporary
- * storage requirements vary from a small constant for nearly sorted
- * input arrays to n/2 object references for randomly ordered input
- * arrays.
- *
- *
The implementation takes equal advantage of ascending and
- * descending order in its input array, and can take advantage of
- * ascending and descending order in different parts of the same
- * input array. It is well-suited to merging two or more sorted arrays:
- * simply concatenate the arrays and sort the resulting array.
- *
- *
The implementation was adapted from Tim Peters's list sort for Python
- * (
- * TimSort). It uses techiques from Peter McIlroy's "Optimistic
- * Sorting and Information Theoretic Complexity", in Proceedings of the
- * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
- * January 1993.
- *
- *
This implementation dumps the specified list into an array, sorts
- * the array, and iterates over the list resetting each element
- * from the corresponding position in the array. This avoids the
- * n2 log(n) performance that would result from attempting
- * to sort a linked list in place.
- *
- * @param list the list to be sorted.
- * @param c the comparator to determine the order of the list. A
- * {@code null} value indicates that the elements' natural
- * ordering should be used.
- * @throws ClassCastException if the list contains elements that are not
- * mutually comparable using the specified comparator.
- * @throws UnsupportedOperationException if the specified list's
- * list-iterator does not support the {@code set} operation.
- * @throws IllegalArgumentException (optional) if the comparator is
- * found to violate the {@link Comparator} contract
- */
- public static void sort(List list, Comparator c) {
- Object[] a = list.toArray();
- Arrays.sort(a, (Comparator)c);
- ListIterator i = list.listIterator();
- for (int j=0; jThis method runs in log(n) time for a "random access" list (which
- * provides near-constant-time positional access). If the specified list
- * does not implement the {@link RandomAccess} interface and is large,
- * this method will do an iterator-based binary search that performs
- * O(n) link traversals and O(log n) element comparisons.
- *
- * @param list the list to be searched.
- * @param key the key to be searched for.
- * @return the index of the search key, if it is contained in the list;
- * otherwise, (-(insertion point) - 1). The
- * insertion point is defined as the point at which the
- * key would be inserted into the list: the index of the first
- * element greater than the key, or list.size() if all
- * elements in the list are less than the specified key. Note
- * that this guarantees that the return value will be >= 0 if
- * and only if the key is found.
- * @throws ClassCastException if the list contains elements that are not
- * mutually comparable (for example, strings and
- * integers), or the search key is not mutually comparable
- * with the elements of the list.
- */
- public static
- int binarySearch(List> list, T key) {
- if (list instanceof RandomAccess || list.size()
- int indexedBinarySearch(List> list, T key)
- {
- int low = 0;
- int high = list.size()-1;
-
- while (low <= high) {
- int mid = (low + high) >>> 1;
- Comparable midVal = list.get(mid);
- int cmp = midVal.compareTo(key);
-
- if (cmp < 0)
- low = mid + 1;
- else if (cmp > 0)
- high = mid - 1;
- else
- return mid; // key found
- }
- return -(low + 1); // key not found
- }
-
- private static
- int iteratorBinarySearch(List> list, T key)
- {
- int low = 0;
- int high = list.size()-1;
- ListIterator> i = list.listIterator();
-
- while (low <= high) {
- int mid = (low + high) >>> 1;
- Comparable midVal = get(i, mid);
- int cmp = midVal.compareTo(key);
-
- if (cmp < 0)
- low = mid + 1;
- else if (cmp > 0)
- high = mid - 1;
- else
- return mid; // key found
- }
- return -(low + 1); // key not found
- }
-
- /**
- * Gets the ith element from the given list by repositioning the specified
- * list listIterator.
- */
- private static T get(ListIterator i, int index) {
- T obj = null;
- int pos = i.nextIndex();
- if (pos <= index) {
- do {
- obj = i.next();
- } while (pos++ < index);
- } else {
- do {
- obj = i.previous();
- } while (--pos > index);
- }
- return obj;
- }
-
- /**
- * Searches the specified list for the specified object using the binary
- * search algorithm. The list must be sorted into ascending order
- * according to the specified comparator (as by the
- * {@link #sort(List, Comparator) sort(List, Comparator)}
- * method), prior to making this call. If it is
- * not sorted, the results are undefined. If the list contains multiple
- * elements equal to the specified object, there is no guarantee which one
- * will be found.
- *
- * This method runs in log(n) time for a "random access" list (which
- * provides near-constant-time positional access). If the specified list
- * does not implement the {@link RandomAccess} interface and is large,
- * this method will do an iterator-based binary search that performs
- * O(n) link traversals and O(log n) element comparisons.
- *
- * @param list the list to be searched.
- * @param key the key to be searched for.
- * @param c the comparator by which the list is ordered.
- * A null value indicates that the elements'
- * {@linkplain Comparable natural ordering} should be used.
- * @return the index of the search key, if it is contained in the list;
- * otherwise, (-(insertion point) - 1). The
- * insertion point is defined as the point at which the
- * key would be inserted into the list: the index of the first
- * element greater than the key, or list.size() if all
- * elements in the list are less than the specified key. Note
- * that this guarantees that the return value will be >= 0 if
- * and only if the key is found.
- * @throws ClassCastException if the list contains elements that are not
- * mutually comparable using the specified comparator,
- * or the search key is not mutually comparable with the
- * elements of the list using this comparator.
- */
- public static int binarySearch(List list, T key, Comparator c) {
- if (c==null)
- return binarySearch((List) list, key);
-
- if (list instanceof RandomAccess || list.size() int indexedBinarySearch(List l, T key, Comparator c) {
- int low = 0;
- int high = l.size()-1;
-
- while (low <= high) {
- int mid = (low + high) >>> 1;
- T midVal = l.get(mid);
- int cmp = c.compare(midVal, key);
-
- if (cmp < 0)
- low = mid + 1;
- else if (cmp > 0)
- high = mid - 1;
- else
- return mid; // key found
- }
- return -(low + 1); // key not found
- }
-
- private static int iteratorBinarySearch(List l, T key, Comparator c) {
- int low = 0;
- int high = l.size()-1;
- ListIterator i = l.listIterator();
-
- while (low <= high) {
- int mid = (low + high) >>> 1;
- T midVal = get(i, mid);
- int cmp = c.compare(midVal, key);
-
- if (cmp < 0)
- low = mid + 1;
- else if (cmp > 0)
- high = mid - 1;
- else
- return mid; // key found
- }
- return -(low + 1); // key not found
- }
-
- private interface SelfComparable extends Comparable {}
-
-
- /**
- * Reverses the order of the elements in the specified list.
- *
- * This method runs in linear time.
- *
- * @param list the list whose elements are to be reversed.
- * @throws UnsupportedOperationException if the specified list or
- * its list-iterator does not support the set operation.
- */
- public static void reverse(List list) {
- int size = list.size();
- if (size < REVERSE_THRESHOLD || list instanceof RandomAccess) {
- for (int i=0, mid=size>>1, j=size-1; i>1; i
- *
- * The hedge "approximately" is used in the foregoing description because
- * default source of randomness is only approximately an unbiased source
- * of independently chosen bits. If it were a perfect source of randomly
- * chosen bits, then the algorithm would choose permutations with perfect
- * uniformity.
- *
- * This implementation traverses the list backwards, from the last element
- * up to the second, repeatedly swapping a randomly selected element into
- * the "current position". Elements are randomly selected from the
- * portion of the list that runs from the first element to the current
- * position, inclusive.
- *
- * This method runs in linear time. If the specified list does not
- * implement the {@link RandomAccess} interface and is large, this
- * implementation dumps the specified list into an array before shuffling
- * it, and dumps the shuffled array back into the list. This avoids the
- * quadratic behavior that would result from shuffling a "sequential
- * access" list in place.
- *
- * @param list the list to be shuffled.
- * @throws UnsupportedOperationException if the specified list or
- * its list-iterator does not support the set operation.
- */
- public static void shuffle(List list) {
- Random rnd = r;
- if (rnd == null)
- r = rnd = new Random();
- shuffle(list, rnd);
- }
- private static Random r;
-
- /**
- * Randomly permute the specified list using the specified source of
- * randomness. All permutations occur with equal likelihood
- * assuming that the source of randomness is fair.
- *
- * This implementation traverses the list backwards, from the last element
- * up to the second, repeatedly swapping a randomly selected element into
- * the "current position". Elements are randomly selected from the
- * portion of the list that runs from the first element to the current
- * position, inclusive.
- *
- * This method runs in linear time. If the specified list does not
- * implement the {@link RandomAccess} interface and is large, this
- * implementation dumps the specified list into an array before shuffling
- * it, and dumps the shuffled array back into the list. This avoids the
- * quadratic behavior that would result from shuffling a "sequential
- * access" list in place.
- *
- * @param list the list to be shuffled.
- * @param rnd the source of randomness to use to shuffle the list.
- * @throws UnsupportedOperationException if the specified list or its
- * list-iterator does not support the set operation.
- */
- public static void shuffle(List list, Random rnd) {
- int size = list.size();
- if (size < SHUFFLE_THRESHOLD || list instanceof RandomAccess) {
- for (int i=size; i>1; i--)
- swap(list, i-1, rnd.nextInt(i));
- } else {
- Object arr[] = list.toArray();
-
- // Shuffle array
- for (int i=size; i>1; i--)
- swap(arr, i-1, rnd.nextInt(i));
-
- // Dump array back into list
- ListIterator it = list.listIterator();
- for (int i=0; ii or j
- * is out of range (i < 0 || i >= list.size()
- * || j < 0 || j >= list.size()).
- * @since 1.4
- */
- public static void swap(List list, int i, int j) {
- final List l = list;
- l.set(i, l.set(j, l.get(i)));
- }
-
- /**
- * Swaps the two specified elements in the specified array.
- */
- private static void swap(Object[] arr, int i, int j) {
- Object tmp = arr[i];
- arr[i] = arr[j];
- arr[j] = tmp;
- }
-
- /**
- * Replaces all of the elements of the specified list with the specified
- * element.
- *
- * This method runs in linear time.
- *
- * @param list the list to be filled with the specified element.
- * @param obj The element with which to fill the specified list.
- * @throws UnsupportedOperationException if the specified list or its
- * list-iterator does not support the set operation.
- */
- public static void fill(List list, T obj) {
- int size = list.size();
-
- if (size < FILL_THRESHOLD || list instanceof RandomAccess) {
- for (int i=0; i itr = list.listIterator();
- for (int i=0; i
- *
- * This method runs in linear time.
- *
- * @param dest The destination list.
- * @param src The source list.
- * @throws IndexOutOfBoundsException if the destination list is too small
- * to contain the entire source List.
- * @throws UnsupportedOperationException if the destination list's
- * list-iterator does not support the set operation.
- */
- public static void copy(List dest, List src) {
- int srcSize = src.size();
- if (srcSize > dest.size())
- throw new IndexOutOfBoundsException("Source does not fit in dest");
-
- if (srcSize < COPY_THRESHOLD ||
- (src instanceof RandomAccess && dest instanceof RandomAccess)) {
- for (int i=0; i di=dest.listIterator();
- ListIterator si=src.listIterator();
- for (int i=0; inatural ordering of its elements. All elements in the
- * collection must implement the Comparable interface.
- * Furthermore, all elements in the collection must be mutually
- * comparable (that is, e1.compareTo(e2) must not throw a
- * ClassCastException for any elements e1 and
- * e2 in the collection).
- *
- * This method iterates over the entire collection, hence it requires
- * time proportional to the size of the collection.
- *
- * @param coll the collection whose minimum element is to be determined.
- * @return the minimum element of the given collection, according
- * to the natural ordering of its elements.
- * @throws ClassCastException if the collection contains elements that are
- * not mutually comparable (for example, strings and
- * integers).
- * @throws NoSuchElementException if the collection is empty.
- * @see Comparable
- */
- public static > T min(Collection coll) {
- Iterator i = coll.iterator();
- T candidate = i.next();
-
- while (i.hasNext()) {
- T next = i.next();
- if (next.compareTo(candidate) < 0)
- candidate = next;
- }
- return candidate;
- }
-
- /**
- * Returns the minimum element of the given collection, according to the
- * order induced by the specified comparator. All elements in the
- * collection must be mutually comparable by the specified
- * comparator (that is, comp.compare(e1, e2) must not throw a
- * ClassCastException for any elements e1 and
- * e2 in the collection).
- *
- * This method iterates over the entire collection, hence it requires
- * time proportional to the size of the collection.
- *
- * @param coll the collection whose minimum element is to be determined.
- * @param comp the comparator with which to determine the minimum element.
- * A null value indicates that the elements' natural
- * ordering should be used.
- * @return the minimum element of the given collection, according
- * to the specified comparator.
- * @throws ClassCastException if the collection contains elements that are
- * not mutually comparable using the specified comparator.
- * @throws NoSuchElementException if the collection is empty.
- * @see Comparable
- */
- public static T min(Collection coll, Comparator comp) {
- if (comp==null)
- return (T)min((Collection) (Collection) coll);
-
- Iterator i = coll.iterator();
- T candidate = i.next();
-
- while (i.hasNext()) {
- T next = i.next();
- if (comp.compare(next, candidate) < 0)
- candidate = next;
- }
- return candidate;
- }
-
- /**
- * Returns the maximum element of the given collection, according to the
- * natural ordering of its elements. All elements in the
- * collection must implement the Comparable interface.
- * Furthermore, all elements in the collection must be mutually
- * comparable (that is, e1.compareTo(e2) must not throw a
- * ClassCastException for any elements e1 and
- * e2 in the collection).
- *
- * This method iterates over the entire collection, hence it requires
- * time proportional to the size of the collection.
- *
- * @param coll the collection whose maximum element is to be determined.
- * @return the maximum element of the given collection, according
- * to the natural ordering of its elements.
- * @throws ClassCastException if the collection contains elements that are
- * not mutually comparable (for example, strings and
- * integers).
- * @throws NoSuchElementException if the collection is empty.
- * @see Comparable
- */
- public static > T max(Collection coll) {
- Iterator i = coll.iterator();
- T candidate = i.next();
-
- while (i.hasNext()) {
- T next = i.next();
- if (next.compareTo(candidate) > 0)
- candidate = next;
- }
- return candidate;
- }
-
- /**
- * Returns the maximum element of the given collection, according to the
- * order induced by the specified comparator. All elements in the
- * collection must be mutually comparable by the specified
- * comparator (that is, comp.compare(e1, e2) must not throw a
- * ClassCastException for any elements e1 and
- * e2 in the collection).
- *
- * This method iterates over the entire collection, hence it requires
- * time proportional to the size of the collection.
- *
- * @param coll the collection whose maximum element is to be determined.
- * @param comp the comparator with which to determine the maximum element.
- * A null value indicates that the elements' natural
- * ordering should be used.
- * @return the maximum element of the given collection, according
- * to the specified comparator.
- * @throws ClassCastException if the collection contains elements that are
- * not mutually comparable using the specified comparator.
- * @throws NoSuchElementException if the collection is empty.
- * @see Comparable
- */
- public static T max(Collection coll, Comparator comp) {
- if (comp==null)
- return (T)max((Collection) (Collection) coll);
-
- Iterator i = coll.iterator();
- T candidate = i.next();
-
- while (i.hasNext()) {
- T next = i.next();
- if (comp.compare(next, candidate) > 0)
- candidate = next;
- }
- return candidate;
- }
-
- /**
- * Rotates the elements in the specified list by the specified distance.
- * After calling this method, the element at index i will be
- * the element previously at index (i - distance) mod
- * list.size(), for all values of i between 0
- * and list.size()-1, inclusive. (This method has no effect on
- * the size of the list.)
- *
- * For example, suppose list comprises [t, a, n, k, s].
- * After invoking Collections.rotate(list, 1) (or
- * Collections.rotate(list, -4)), list will comprise
- * [s, t, a, n, k].
- *
- *
Note that this method can usefully be applied to sublists to
- * move one or more elements within a list while preserving the
- * order of the remaining elements. For example, the following idiom
- * moves the element at index j forward to position
- * k (which must be greater than or equal to j):
- *
- * Collections.rotate(list.subList(j, k+1), -1);
- *
- * To make this concrete, suppose list comprises
- * [a, b, c, d, e]. To move the element at index 1
- * (b) forward two positions, perform the following invocation:
- *
- * Collections.rotate(l.subList(1, 4), -1);
- *
- * The resulting list is [a, c, d, b, e].
- *
- * To move more than one element forward, increase the absolute value
- * of the rotation distance. To move elements backward, use a positive
- * shift distance.
- *
- *
If the specified list is small or implements the {@link
- * RandomAccess} interface, this implementation exchanges the first
- * element into the location it should go, and then repeatedly exchanges
- * the displaced element into the location it should go until a displaced
- * element is swapped into the first element. If necessary, the process
- * is repeated on the second and successive elements, until the rotation
- * is complete. If the specified list is large and doesn't implement the
- * RandomAccess interface, this implementation breaks the
- * list into two sublist views around index -distance mod size.
- * Then the {@link #reverse(List)} method is invoked on each sublist view,
- * and finally it is invoked on the entire list. For a more complete
- * description of both algorithms, see Section 2.3 of Jon Bentley's
- * Programming Pearls (Addison-Wesley, 1986).
- *
- * @param list the list to be rotated.
- * @param distance the distance to rotate the list. There are no
- * constraints on this value; it may be zero, negative, or
- * greater than list.size().
- * @throws UnsupportedOperationException if the specified list or
- * its list-iterator does not support the set operation.
- * @since 1.4
- */
- public static void rotate(List list, int distance) {
- if (list instanceof RandomAccess || list.size() < ROTATE_THRESHOLD)
- rotate1(list, distance);
- else
- rotate2(list, distance);
- }
-
- private static void rotate1(List list, int distance) {
- int size = list.size();
- if (size == 0)
- return;
- distance = distance % size;
- if (distance < 0)
- distance += size;
- if (distance == 0)
- return;
-
- for (int cycleStart = 0, nMoved = 0; nMoved != size; cycleStart++) {
- T displaced = list.get(cycleStart);
- int i = cycleStart;
- do {
- i += distance;
- if (i >= size)
- i -= size;
- displaced = list.set(i, displaced);
- nMoved ++;
- } while (i != cycleStart);
- }
- }
-
- private static void rotate2(List list, int distance) {
- int size = list.size();
- if (size == 0)
- return;
- int mid = -distance % size;
- if (mid < 0)
- mid += size;
- if (mid == 0)
- return;
-
- reverse(list.subList(0, mid));
- reverse(list.subList(mid, size));
- reverse(list);
- }
-
- /**
- * Replaces all occurrences of one specified value in a list with another.
- * More formally, replaces with newVal each element e
- * in list such that
- * (oldVal==null ? e==null : oldVal.equals(e)).
- * (This method has no effect on the size of the list.)
- *
- * @param list the list in which replacement is to occur.
- * @param oldVal the old value to be replaced.
- * @param newVal the new value with which oldVal is to be
- * replaced.
- * @return true if list contained one or more elements
- * e such that
- * (oldVal==null ? e==null : oldVal.equals(e)).
- * @throws UnsupportedOperationException if the specified list or
- * its list-iterator does not support the set operation.
- * @since 1.4
- */
- public static boolean replaceAll(List list, T oldVal, T newVal) {
- boolean result = false;
- int size = list.size();
- if (size < REPLACEALL_THRESHOLD || list instanceof RandomAccess) {
- if (oldVal==null) {
- for (int i=0; i itr=list.listIterator();
- if (oldVal==null) {
- for (int i=0; ii
- * such that source.subList(i, i+target.size()).equals(target),
- * or -1 if there is no such index. (Returns -1 if
- * target.size() > source.size().)
- *
- * This implementation uses the "brute force" technique of scanning
- * over the source list, looking for a match with the target at each
- * location in turn.
- *
- * @param source the list in which to search for the first occurrence
- * of target.
- * @param target the list to search for as a subList of source.
- * @return the starting position of the first occurrence of the specified
- * target list within the specified source list, or -1 if there
- * is no such occurrence.
- * @since 1.4
- */
- public static int indexOfSubList(List source, List target) {
- int sourceSize = source.size();
- int targetSize = target.size();
- int maxCandidate = sourceSize - targetSize;
-
- if (sourceSize < INDEXOFSUBLIST_THRESHOLD ||
- (source instanceof RandomAccess&&target instanceof RandomAccess)) {
- nextCand:
- for (int candidate = 0; candidate <= maxCandidate; candidate++) {
- for (int i=0, j=candidate; i si = source.listIterator();
- nextCand:
- for (int candidate = 0; candidate <= maxCandidate; candidate++) {
- ListIterator ti = target.listIterator();
- for (int i=0; ii
- * such that source.subList(i, i+target.size()).equals(target),
- * or -1 if there is no such index. (Returns -1 if
- * target.size() > source.size().)
- *
- * This implementation uses the "brute force" technique of iterating
- * over the source list, looking for a match with the target at each
- * location in turn.
- *
- * @param source the list in which to search for the last occurrence
- * of target.
- * @param target the list to search for as a subList of source.
- * @return the starting position of the last occurrence of the specified
- * target list within the specified source list, or -1 if there
- * is no such occurrence.
- * @since 1.4
- */
- public static int lastIndexOfSubList(List source, List target) {
- int sourceSize = source.size();
- int targetSize = target.size();
- int maxCandidate = sourceSize - targetSize;
-
- if (sourceSize < INDEXOFSUBLIST_THRESHOLD ||
- source instanceof RandomAccess) { // Index access version
- nextCand:
- for (int candidate = maxCandidate; candidate >= 0; candidate--) {
- for (int i=0, j=candidate; i si = source.listIterator(maxCandidate);
- nextCand:
- for (int candidate = maxCandidate; candidate >= 0; candidate--) {
- ListIterator ti = target.listIterator();
- for (int i=0; iUnsupportedOperationException.
- *
- * The returned collection does not pass the hashCode and equals
- * operations through to the backing collection, but relies on
- * Object's equals and hashCode methods. This
- * is necessary to preserve the contracts of these operations in the case
- * that the backing collection is a set or a list.
- *
- * The returned collection will be serializable if the specified collection
- * is serializable.
- *
- * @param c the collection for which an unmodifiable view is to be
- * returned.
- * @return an unmodifiable view of the specified collection.
- */
- public static Collection unmodifiableCollection(Collection c) {
- return new UnmodifiableCollection<>(c);
- }
-
- /**
- * @serial include
- */
- static class UnmodifiableCollection implements Collection, Serializable {
- private static final long serialVersionUID = 1820017752578914078L;
-
- final Collection c;
-
- UnmodifiableCollection(Collection c) {
- if (c==null)
- throw new NullPointerException();
- this.c = c;
- }
-
- public int size() {return c.size();}
- public boolean isEmpty() {return c.isEmpty();}
- public boolean contains(Object o) {return c.contains(o);}
- public Object[] toArray() {return c.toArray();}
- public T[] toArray(T[] a) {return c.toArray(a);}
- public String toString() {return c.toString();}
-
- public Iterator iterator() {
- return new Iterator() {
- private final Iterator i = c.iterator();
-
- public boolean hasNext() {return i.hasNext();}
- public E next() {return i.next();}
- public void remove() {
- throw new UnsupportedOperationException();
- }
- };
- }
-
- public boolean add(E e) {
- throw new UnsupportedOperationException();
- }
- public boolean remove(Object o) {
- throw new UnsupportedOperationException();
- }
-
- public boolean containsAll(Collection coll) {
- return c.containsAll(coll);
- }
- public boolean addAll(Collection coll) {
- throw new UnsupportedOperationException();
- }
- public boolean removeAll(Collection coll) {
- throw new UnsupportedOperationException();
- }
- public boolean retainAll(Collection coll) {
- throw new UnsupportedOperationException();
- }
- public void clear() {
- throw new UnsupportedOperationException();
- }
- }
-
- /**
- * Returns an unmodifiable view of the specified set. This method allows
- * modules to provide users with "read-only" access to internal sets.
- * Query operations on the returned set "read through" to the specified
- * set, and attempts to modify the returned set, whether direct or via its
- * iterator, result in an UnsupportedOperationException.
- *
- * The returned set will be serializable if the specified set
- * is serializable.
- *
- * @param s the set for which an unmodifiable view is to be returned.
- * @return an unmodifiable view of the specified set.
- */
- public static Set unmodifiableSet(Set s) {
- return new UnmodifiableSet<>(s);
- }
-
- /**
- * @serial include
- */
- static class UnmodifiableSet extends UnmodifiableCollection
- implements Set, Serializable {
- private static final long serialVersionUID = -9215047833775013803L;
-
- UnmodifiableSet(Set s) {super(s);}
- public boolean equals(Object o) {return o == this || c.equals(o);}
- public int hashCode() {return c.hashCode();}
- }
-
- /**
- * Returns an unmodifiable view of the specified sorted set. This method
- * allows modules to provide users with "read-only" access to internal
- * sorted sets. Query operations on the returned sorted set "read
- * through" to the specified sorted set. Attempts to modify the returned
- * sorted set, whether direct, via its iterator, or via its
- * subSet, headSet, or tailSet views, result in
- * an UnsupportedOperationException.
- *
- * The returned sorted set will be serializable if the specified sorted set
- * is serializable.
- *
- * @param s the sorted set for which an unmodifiable view is to be
- * returned.
- * @return an unmodifiable view of the specified sorted set.
- */
- public static SortedSet unmodifiableSortedSet(SortedSet s) {
- return new UnmodifiableSortedSet<>(s);
- }
-
- /**
- * @serial include
- */
- static class UnmodifiableSortedSet
- extends UnmodifiableSet
- implements SortedSet, Serializable {
- private static final long serialVersionUID = -4929149591599911165L;
- private final SortedSet ss;
-
- UnmodifiableSortedSet(SortedSet s) {super(s); ss = s;}
-
- public Comparator comparator() {return ss.comparator();}
-
- public SortedSet subSet(E fromElement, E toElement) {
- return new UnmodifiableSortedSet<>(ss.subSet(fromElement,toElement));
- }
- public SortedSet headSet(E toElement) {
- return new UnmodifiableSortedSet<>(ss.headSet(toElement));
- }
- public SortedSet tailSet(E fromElement) {
- return new UnmodifiableSortedSet<>(ss.tailSet(fromElement));
- }
-
- public E first() {return ss.first();}
- public E last() {return ss.last();}
- }
-
- /**
- * Returns an unmodifiable view of the specified list. This method allows
- * modules to provide users with "read-only" access to internal
- * lists. Query operations on the returned list "read through" to the
- * specified list, and attempts to modify the returned list, whether
- * direct or via its iterator, result in an
- * UnsupportedOperationException.
- *
- * The returned list will be serializable if the specified list
- * is serializable. Similarly, the returned list will implement
- * {@link RandomAccess} if the specified list does.
- *
- * @param list the list for which an unmodifiable view is to be returned.
- * @return an unmodifiable view of the specified list.
- */
- public static List unmodifiableList(List list) {
- return (list instanceof RandomAccess ?
- new UnmodifiableRandomAccessList<>(list) :
- new UnmodifiableList<>(list));
- }
-
- /**
- * @serial include
- */
- static class UnmodifiableList extends UnmodifiableCollection
- implements List {
- private static final long serialVersionUID = -283967356065247728L;
- final List list;
-
- UnmodifiableList(List list) {
- super(list);
- this.list = list;
- }
-
- public boolean equals(Object o) {return o == this || list.equals(o);}
- public int hashCode() {return list.hashCode();}
-
- public E get(int index) {return list.get(index);}
- public E set(int index, E element) {
- throw new UnsupportedOperationException();
- }
- public void add(int index, E element) {
- throw new UnsupportedOperationException();
- }
- public E remove(int index) {
- throw new UnsupportedOperationException();
- }
- public int indexOf(Object o) {return list.indexOf(o);}
- public int lastIndexOf(Object o) {return list.lastIndexOf(o);}
- public boolean addAll(int index, Collection c) {
- throw new UnsupportedOperationException();
- }
- public ListIterator listIterator() {return listIterator(0);}
-
- public ListIterator listIterator(final int index) {
- return new ListIterator() {
- private final ListIterator i
- = list.listIterator(index);
-
- public boolean hasNext() {return i.hasNext();}
- public E next() {return i.next();}
- public boolean hasPrevious() {return i.hasPrevious();}
- public E previous() {return i.previous();}
- public int nextIndex() {return i.nextIndex();}
- public int previousIndex() {return i.previousIndex();}
-
- public void remove() {
- throw new UnsupportedOperationException();
- }
- public void set(E e) {
- throw new UnsupportedOperationException();
- }
- public void add(E e) {
- throw new UnsupportedOperationException();
- }
- };
- }
-
- public List subList(int fromIndex, int toIndex) {
- return new UnmodifiableList<>(list.subList(fromIndex, toIndex));
- }
-
- /**
- * UnmodifiableRandomAccessList instances are serialized as
- * UnmodifiableList instances to allow them to be deserialized
- * in pre-1.4 JREs (which do not have UnmodifiableRandomAccessList).
- * This method inverts the transformation. As a beneficial
- * side-effect, it also grafts the RandomAccess marker onto
- * UnmodifiableList instances that were serialized in pre-1.4 JREs.
- *
- * Note: Unfortunately, UnmodifiableRandomAccessList instances
- * serialized in 1.4.1 and deserialized in 1.4 will become
- * UnmodifiableList instances, as this method was missing in 1.4.
- */
- private Object readResolve() {
- return (list instanceof RandomAccess
- ? new UnmodifiableRandomAccessList<>(list)
- : this);
- }
- }
-
- /**
- * @serial include
- */
- static class UnmodifiableRandomAccessList extends UnmodifiableList
- implements RandomAccess
- {
- UnmodifiableRandomAccessList(List list) {
- super(list);
- }
-
- public List subList(int fromIndex, int toIndex) {
- return new UnmodifiableRandomAccessList<>(
- list.subList(fromIndex, toIndex));
- }
-
- private static final long serialVersionUID = -2542308836966382001L;
-
- /**
- * Allows instances to be deserialized in pre-1.4 JREs (which do
- * not have UnmodifiableRandomAccessList). UnmodifiableList has
- * a readResolve method that inverts this transformation upon
- * deserialization.
- */
- private Object writeReplace() {
- return new UnmodifiableList<>(list);
- }
- }
-
- /**
- * Returns an unmodifiable view of the specified map. This method
- * allows modules to provide users with "read-only" access to internal
- * maps. Query operations on the returned map "read through"
- * to the specified map, and attempts to modify the returned
- * map, whether direct or via its collection views, result in an
- * UnsupportedOperationException.
- *
- * The returned map will be serializable if the specified map
- * is serializable.
- *
- * @param m the map for which an unmodifiable view is to be returned.
- * @return an unmodifiable view of the specified map.
- */
- public static Map unmodifiableMap(Map m) {
- return new UnmodifiableMap<>(m);
- }
-
- /**
- * @serial include
- */
- private static class UnmodifiableMap implements Map, Serializable {
- private static final long serialVersionUID = -1034234728574286014L;
-
- private final Map m;
-
- UnmodifiableMap(Map m) {
- if (m==null)
- throw new NullPointerException();
- this.m = m;
- }
-
- public int size() {return m.size();}
- public boolean isEmpty() {return m.isEmpty();}
- public boolean containsKey(Object key) {return m.containsKey(key);}
- public boolean containsValue(Object val) {return m.containsValue(val);}
- public V get(Object key) {return m.get(key);}
-
- public V put(K key, V value) {
- throw new UnsupportedOperationException();
- }
- public V remove(Object key) {
- throw new UnsupportedOperationException();
- }
- public void putAll(Map m) {
- throw new UnsupportedOperationException();
- }
- public void clear() {
- throw new UnsupportedOperationException();
- }
-
- private transient Set keySet = null;
- private transient Set> entrySet = null;
- private transient Collection values = null;
-
- public Set keySet() {
- if (keySet==null)
- keySet = unmodifiableSet(m.keySet());
- return keySet;
- }
-
- public Set> entrySet() {
- if (entrySet==null)
- entrySet = new UnmodifiableEntrySet<>(m.entrySet());
- return entrySet;
- }
-
- public Collection values() {
- if (values==null)
- values = unmodifiableCollection(m.values());
- return values;
- }
-
- public boolean equals(Object o) {return o == this || m.equals(o);}
- public int hashCode() {return m.hashCode();}
- public String toString() {return m.toString();}
-
- /**
- * We need this class in addition to UnmodifiableSet as
- * Map.Entries themselves permit modification of the backing Map
- * via their setValue operation. This class is subtle: there are
- * many possible attacks that must be thwarted.
- *
- * @serial include
- */
- static class UnmodifiableEntrySet
- extends UnmodifiableSet> {
- private static final long serialVersionUID = 7854390611657943733L;
-
- UnmodifiableEntrySet(Set> s) {
- super((Set)s);
- }
- public Iterator> iterator() {
- return new Iterator>() {
- private final Iterator> i = c.iterator();
-
- public boolean hasNext() {
- return i.hasNext();
- }
- public Map.Entry next() {
- return new UnmodifiableEntry<>(i.next());
- }
- public void remove() {
- throw new UnsupportedOperationException();
- }
- };
- }
-
- public Object[] toArray() {
- Object[] a = c.toArray();
- for (int i=0; i((Map.Entry)a[i]);
- return a;
- }
-
- public T[] toArray(T[] a) {
- // We don't pass a to c.toArray, to avoid window of
- // vulnerability wherein an unscrupulous multithreaded client
- // could get his hands on raw (unwrapped) Entries from c.
- Object[] arr = c.toArray(a.length==0 ? a : Arrays.copyOf(a, 0));
-
- for (int i=0; i((Map.Entry)arr[i]);
-
- if (arr.length > a.length)
- return (T[])arr;
-
- System.arraycopy(arr, 0, a, 0, arr.length);
- if (a.length > arr.length)
- a[arr.length] = null;
- return a;
- }
-
- /**
- * This method is overridden to protect the backing set against
- * an object with a nefarious equals function that senses
- * that the equality-candidate is Map.Entry and calls its
- * setValue method.
- */
- public boolean contains(Object o) {
- if (!(o instanceof Map.Entry))
- return false;
- return c.contains(
- new UnmodifiableEntry<>((Map.Entry) o));
- }
-
- /**
- * The next two methods are overridden to protect against
- * an unscrupulous List whose contains(Object o) method senses
- * when o is a Map.Entry, and calls o.setValue.
- */
- public boolean containsAll(Collection coll) {
- for (Object e : coll) {
- if (!contains(e)) // Invokes safe contains() above
- return false;
- }
- return true;
- }
- public boolean equals(Object o) {
- if (o == this)
- return true;
-
- if (!(o instanceof Set))
- return false;
- Set s = (Set) o;
- if (s.size() != c.size())
- return false;
- return containsAll(s); // Invokes safe containsAll() above
- }
-
- /**
- * This "wrapper class" serves two purposes: it prevents
- * the client from modifying the backing Map, by short-circuiting
- * the setValue method, and it protects the backing Map against
- * an ill-behaved Map.Entry that attempts to modify another
- * Map Entry when asked to perform an equality check.
- */
- private static class UnmodifiableEntry implements Map.Entry {
- private Map.Entry e;
-
- UnmodifiableEntry(Map.Entry e) {this.e = e;}
-
- public K getKey() {return e.getKey();}
- public V getValue() {return e.getValue();}
- public V setValue(V value) {
- throw new UnsupportedOperationException();
- }
- public int hashCode() {return e.hashCode();}
- public boolean equals(Object o) {
- if (!(o instanceof Map.Entry))
- return false;
- Map.Entry t = (Map.Entry)o;
- return eq(e.getKey(), t.getKey()) &&
- eq(e.getValue(), t.getValue());
- }
- public String toString() {return e.toString();}
- }
- }
- }
-
- /**
- * Returns an unmodifiable view of the specified sorted map. This method
- * allows modules to provide users with "read-only" access to internal
- * sorted maps. Query operations on the returned sorted map "read through"
- * to the specified sorted map. Attempts to modify the returned
- * sorted map, whether direct, via its collection views, or via its
- * subMap, headMap, or tailMap views, result in
- * an UnsupportedOperationException.
- *
- * The returned sorted map will be serializable if the specified sorted map
- * is serializable.
- *
- * @param m the sorted map for which an unmodifiable view is to be
- * returned.
- * @return an unmodifiable view of the specified sorted map.
- */
- public static SortedMap unmodifiableSortedMap(SortedMap m) {
- return new UnmodifiableSortedMap<>(m);
- }
-
- /**
- * @serial include
- */
- static class UnmodifiableSortedMap
- extends UnmodifiableMap
- implements SortedMap, Serializable {
- private static final long serialVersionUID = -8806743815996713206L;
-
- private final SortedMap sm;
-
- UnmodifiableSortedMap(SortedMap m) {super(m); sm = m;}
-
- public Comparator comparator() {return sm.comparator();}
-
- public SortedMap subMap(K fromKey, K toKey) {
- return new UnmodifiableSortedMap<>(sm.subMap(fromKey, toKey));
- }
- public SortedMap headMap(K toKey) {
- return new UnmodifiableSortedMap<>(sm.headMap(toKey));
- }
- public SortedMap tailMap(K fromKey) {
- return new UnmodifiableSortedMap<>(sm.tailMap(fromKey));
- }
-
- public K firstKey() {return sm.firstKey();}
- public K lastKey() {return sm.lastKey();}
- }
-
-
- // Synch Wrappers
-
- /**
- * Returns a synchronized (thread-safe) collection backed by the specified
- * collection. In order to guarantee serial access, it is critical that
- * all access to the backing collection is accomplished
- * through the returned collection.
- *
- * It is imperative that the user manually synchronize on the returned
- * collection when iterating over it:
- *
- * Collection c = Collections.synchronizedCollection(myCollection);
- * ...
- * synchronized (c) {
- * Iterator i = c.iterator(); // Must be in the synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * Failure to follow this advice may result in non-deterministic behavior.
- *
- * The returned collection does not pass the hashCode
- * and equals operations through to the backing collection, but
- * relies on Object's equals and hashCode methods. This is
- * necessary to preserve the contracts of these operations in the case
- * that the backing collection is a set or a list.
- *
- * The returned collection will be serializable if the specified collection
- * is serializable.
- *
- * @param c the collection to be "wrapped" in a synchronized collection.
- * @return a synchronized view of the specified collection.
- */
- public static Collection synchronizedCollection(Collection c) {
- return new SynchronizedCollection<>(c);
- }
-
- static Collection synchronizedCollection(Collection c, Object mutex) {
- return new SynchronizedCollection<>(c, mutex);
- }
-
- /**
- * @serial include
- */
- static class SynchronizedCollection implements Collection, Serializable {
- private static final long serialVersionUID = 3053995032091335093L;
-
- final Collection c; // Backing Collection
- final Object mutex; // Object on which to synchronize
-
- SynchronizedCollection(Collection c) {
- if (c==null)
- throw new NullPointerException();
- this.c = c;
- mutex = this;
- }
- SynchronizedCollection(Collection c, Object mutex) {
- this.c = c;
- this.mutex = mutex;
- }
-
- public int size() {
- synchronized (mutex) {return c.size();}
- }
- public boolean isEmpty() {
- synchronized (mutex) {return c.isEmpty();}
- }
- public boolean contains(Object o) {
- synchronized (mutex) {return c.contains(o);}
- }
- public Object[] toArray() {
- synchronized (mutex) {return c.toArray();}
- }
- public T[] toArray(T[] a) {
- synchronized (mutex) {return c.toArray(a);}
- }
-
- public Iterator iterator() {
- return c.iterator(); // Must be manually synched by user!
- }
-
- public boolean add(E e) {
- synchronized (mutex) {return c.add(e);}
- }
- public boolean remove(Object o) {
- synchronized (mutex) {return c.remove(o);}
- }
-
- public boolean containsAll(Collection coll) {
- synchronized (mutex) {return c.containsAll(coll);}
- }
- public boolean addAll(Collection coll) {
- synchronized (mutex) {return c.addAll(coll);}
- }
- public boolean removeAll(Collection coll) {
- synchronized (mutex) {return c.removeAll(coll);}
- }
- public boolean retainAll(Collection coll) {
- synchronized (mutex) {return c.retainAll(coll);}
- }
- public void clear() {
- synchronized (mutex) {c.clear();}
- }
- public String toString() {
- synchronized (mutex) {return c.toString();}
- }
- }
-
- /**
- * Returns a synchronized (thread-safe) set backed by the specified
- * set. In order to guarantee serial access, it is critical that
- * all access to the backing set is accomplished
- * through the returned set.
- *
- * It is imperative that the user manually synchronize on the returned
- * set when iterating over it:
- *
- * Set s = Collections.synchronizedSet(new HashSet());
- * ...
- * synchronized (s) {
- * Iterator i = s.iterator(); // Must be in the synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * Failure to follow this advice may result in non-deterministic behavior.
- *
- * The returned set will be serializable if the specified set is
- * serializable.
- *
- * @param s the set to be "wrapped" in a synchronized set.
- * @return a synchronized view of the specified set.
- */
- public static Set synchronizedSet(Set s) {
- return new SynchronizedSet<>(s);
- }
-
- static Set synchronizedSet(Set s, Object mutex) {
- return new SynchronizedSet<>(s, mutex);
- }
-
- /**
- * @serial include
- */
- static class SynchronizedSet
- extends SynchronizedCollection
- implements Set {
- private static final long serialVersionUID = 487447009682186044L;
-
- SynchronizedSet(Set s) {
- super(s);
- }
- SynchronizedSet(Set s, Object mutex) {
- super(s, mutex);
- }
-
- public boolean equals(Object o) {
- synchronized (mutex) {return c.equals(o);}
- }
- public int hashCode() {
- synchronized (mutex) {return c.hashCode();}
- }
- }
-
- /**
- * Returns a synchronized (thread-safe) sorted set backed by the specified
- * sorted set. In order to guarantee serial access, it is critical that
- * all access to the backing sorted set is accomplished
- * through the returned sorted set (or its views).
- *
- * It is imperative that the user manually synchronize on the returned
- * sorted set when iterating over it or any of its subSet,
- * headSet, or tailSet views.
- *
- * SortedSet s = Collections.synchronizedSortedSet(new TreeSet());
- * ...
- * synchronized (s) {
- * Iterator i = s.iterator(); // Must be in the synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * or:
- *
- * SortedSet s = Collections.synchronizedSortedSet(new TreeSet());
- * SortedSet s2 = s.headSet(foo);
- * ...
- * synchronized (s) { // Note: s, not s2!!!
- * Iterator i = s2.iterator(); // Must be in the synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * Failure to follow this advice may result in non-deterministic behavior.
- *
- * The returned sorted set will be serializable if the specified
- * sorted set is serializable.
- *
- * @param s the sorted set to be "wrapped" in a synchronized sorted set.
- * @return a synchronized view of the specified sorted set.
- */
- public static SortedSet synchronizedSortedSet(SortedSet s) {
- return new SynchronizedSortedSet<>(s);
- }
-
- /**
- * @serial include
- */
- static class SynchronizedSortedSet
- extends SynchronizedSet
- implements SortedSet
- {
- private static final long serialVersionUID = 8695801310862127406L;
-
- private final SortedSet ss;
-
- SynchronizedSortedSet(SortedSet s) {
- super(s);
- ss = s;
- }
- SynchronizedSortedSet(SortedSet s, Object mutex) {
- super(s, mutex);
- ss = s;
- }
-
- public Comparator comparator() {
- synchronized (mutex) {return ss.comparator();}
- }
-
- public SortedSet subSet(E fromElement, E toElement) {
- synchronized (mutex) {
- return new SynchronizedSortedSet<>(
- ss.subSet(fromElement, toElement), mutex);
- }
- }
- public SortedSet headSet(E toElement) {
- synchronized (mutex) {
- return new SynchronizedSortedSet<>(ss.headSet(toElement), mutex);
- }
- }
- public SortedSet tailSet(E fromElement) {
- synchronized (mutex) {
- return new SynchronizedSortedSet<>(ss.tailSet(fromElement),mutex);
- }
- }
-
- public E first() {
- synchronized (mutex) {return ss.first();}
- }
- public E last() {
- synchronized (mutex) {return ss.last();}
- }
- }
-
- /**
- * Returns a synchronized (thread-safe) list backed by the specified
- * list. In order to guarantee serial access, it is critical that
- * all access to the backing list is accomplished
- * through the returned list.
- *
- * It is imperative that the user manually synchronize on the returned
- * list when iterating over it:
- *
- * List list = Collections.synchronizedList(new ArrayList());
- * ...
- * synchronized (list) {
- * Iterator i = list.iterator(); // Must be in synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * Failure to follow this advice may result in non-deterministic behavior.
- *
- * The returned list will be serializable if the specified list is
- * serializable.
- *
- * @param list the list to be "wrapped" in a synchronized list.
- * @return a synchronized view of the specified list.
- */
- public static List synchronizedList(List list) {
- return (list instanceof RandomAccess ?
- new SynchronizedRandomAccessList<>(list) :
- new SynchronizedList<>(list));
- }
-
- static List synchronizedList(List list, Object mutex) {
- return (list instanceof RandomAccess ?
- new SynchronizedRandomAccessList<>(list, mutex) :
- new SynchronizedList<>(list, mutex));
- }
-
- /**
- * @serial include
- */
- static class SynchronizedList
- extends SynchronizedCollection
- implements List {
- private static final long serialVersionUID = -7754090372962971524L;
-
- final List list;
-
- SynchronizedList(List list) {
- super(list);
- this.list = list;
- }
- SynchronizedList(List list, Object mutex) {
- super(list, mutex);
- this.list = list;
- }
-
- public boolean equals(Object o) {
- synchronized (mutex) {return list.equals(o);}
- }
- public int hashCode() {
- synchronized (mutex) {return list.hashCode();}
- }
-
- public E get(int index) {
- synchronized (mutex) {return list.get(index);}
- }
- public E set(int index, E element) {
- synchronized (mutex) {return list.set(index, element);}
- }
- public void add(int index, E element) {
- synchronized (mutex) {list.add(index, element);}
- }
- public E remove(int index) {
- synchronized (mutex) {return list.remove(index);}
- }
-
- public int indexOf(Object o) {
- synchronized (mutex) {return list.indexOf(o);}
- }
- public int lastIndexOf(Object o) {
- synchronized (mutex) {return list.lastIndexOf(o);}
- }
-
- public boolean addAll(int index, Collection c) {
- synchronized (mutex) {return list.addAll(index, c);}
- }
-
- public ListIterator listIterator() {
- return list.listIterator(); // Must be manually synched by user
- }
-
- public ListIterator listIterator(int index) {
- return list.listIterator(index); // Must be manually synched by user
- }
-
- public List subList(int fromIndex, int toIndex) {
- synchronized (mutex) {
- return new SynchronizedList<>(list.subList(fromIndex, toIndex),
- mutex);
- }
- }
-
- /**
- * SynchronizedRandomAccessList instances are serialized as
- * SynchronizedList instances to allow them to be deserialized
- * in pre-1.4 JREs (which do not have SynchronizedRandomAccessList).
- * This method inverts the transformation. As a beneficial
- * side-effect, it also grafts the RandomAccess marker onto
- * SynchronizedList instances that were serialized in pre-1.4 JREs.
- *
- * Note: Unfortunately, SynchronizedRandomAccessList instances
- * serialized in 1.4.1 and deserialized in 1.4 will become
- * SynchronizedList instances, as this method was missing in 1.4.
- */
- private Object readResolve() {
- return (list instanceof RandomAccess
- ? new SynchronizedRandomAccessList<>(list)
- : this);
- }
- }
-
- /**
- * @serial include
- */
- static class SynchronizedRandomAccessList
- extends SynchronizedList
- implements RandomAccess {
-
- SynchronizedRandomAccessList(List list) {
- super(list);
- }
-
- SynchronizedRandomAccessList(List list, Object mutex) {
- super(list, mutex);
- }
-
- public List subList(int fromIndex, int toIndex) {
- synchronized (mutex) {
- return new SynchronizedRandomAccessList<>(
- list.subList(fromIndex, toIndex), mutex);
- }
- }
-
- private static final long serialVersionUID = 1530674583602358482L;
-
- /**
- * Allows instances to be deserialized in pre-1.4 JREs (which do
- * not have SynchronizedRandomAccessList). SynchronizedList has
- * a readResolve method that inverts this transformation upon
- * deserialization.
- */
- private Object writeReplace() {
- return new SynchronizedList<>(list);
- }
- }
-
- /**
- * Returns a synchronized (thread-safe) map backed by the specified
- * map. In order to guarantee serial access, it is critical that
- * all access to the backing map is accomplished
- * through the returned map.
- *
- * It is imperative that the user manually synchronize on the returned
- * map when iterating over any of its collection views:
- *
- * Map m = Collections.synchronizedMap(new HashMap());
- * ...
- * Set s = m.keySet(); // Needn't be in synchronized block
- * ...
- * synchronized (m) { // Synchronizing on m, not s!
- * Iterator i = s.iterator(); // Must be in synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * Failure to follow this advice may result in non-deterministic behavior.
- *
- * The returned map will be serializable if the specified map is
- * serializable.
- *
- * @param m the map to be "wrapped" in a synchronized map.
- * @return a synchronized view of the specified map.
- */
- public static Map synchronizedMap(Map m) {
- return new SynchronizedMap<>(m);
- }
-
- /**
- * @serial include
- */
- private static class SynchronizedMap
- implements Map, Serializable {
- private static final long serialVersionUID = 1978198479659022715L;
-
- private final Map m; // Backing Map
- final Object mutex; // Object on which to synchronize
-
- SynchronizedMap(Map m) {
- if (m==null)
- throw new NullPointerException();
- this.m = m;
- mutex = this;
- }
-
- SynchronizedMap(Map m, Object mutex) {
- this.m = m;
- this.mutex = mutex;
- }
-
- public int size() {
- synchronized (mutex) {return m.size();}
- }
- public boolean isEmpty() {
- synchronized (mutex) {return m.isEmpty();}
- }
- public boolean containsKey(Object key) {
- synchronized (mutex) {return m.containsKey(key);}
- }
- public boolean containsValue(Object value) {
- synchronized (mutex) {return m.containsValue(value);}
- }
- public V get(Object key) {
- synchronized (mutex) {return m.get(key);}
- }
-
- public V put(K key, V value) {
- synchronized (mutex) {return m.put(key, value);}
- }
- public V remove(Object key) {
- synchronized (mutex) {return m.remove(key);}
- }
- public void putAll(Map map) {
- synchronized (mutex) {m.putAll(map);}
- }
- public void clear() {
- synchronized (mutex) {m.clear();}
- }
-
- private transient Set keySet = null;
- private transient Set> entrySet = null;
- private transient Collection values = null;
-
- public Set keySet() {
- synchronized (mutex) {
- if (keySet==null)
- keySet = new SynchronizedSet<>(m.keySet(), mutex);
- return keySet;
- }
- }
-
- public Set> entrySet() {
- synchronized (mutex) {
- if (entrySet==null)
- entrySet = new SynchronizedSet<>(m.entrySet(), mutex);
- return entrySet;
- }
- }
-
- public Collection values() {
- synchronized (mutex) {
- if (values==null)
- values = new SynchronizedCollection<>(m.values(), mutex);
- return values;
- }
- }
-
- public boolean equals(Object o) {
- synchronized (mutex) {return m.equals(o);}
- }
- public int hashCode() {
- synchronized (mutex) {return m.hashCode();}
- }
- public String toString() {
- synchronized (mutex) {return m.toString();}
- }
- }
-
- /**
- * Returns a synchronized (thread-safe) sorted map backed by the specified
- * sorted map. In order to guarantee serial access, it is critical that
- * all access to the backing sorted map is accomplished
- * through the returned sorted map (or its views).
- *
- * It is imperative that the user manually synchronize on the returned
- * sorted map when iterating over any of its collection views, or the
- * collections views of any of its subMap, headMap or
- * tailMap views.
- *
- * SortedMap m = Collections.synchronizedSortedMap(new TreeMap());
- * ...
- * Set s = m.keySet(); // Needn't be in synchronized block
- * ...
- * synchronized (m) { // Synchronizing on m, not s!
- * Iterator i = s.iterator(); // Must be in synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * or:
- *
- * SortedMap m = Collections.synchronizedSortedMap(new TreeMap());
- * SortedMap m2 = m.subMap(foo, bar);
- * ...
- * Set s2 = m2.keySet(); // Needn't be in synchronized block
- * ...
- * synchronized (m) { // Synchronizing on m, not m2 or s2!
- * Iterator i = s.iterator(); // Must be in synchronized block
- * while (i.hasNext())
- * foo(i.next());
- * }
- *
- * Failure to follow this advice may result in non-deterministic behavior.
- *
- * The returned sorted map will be serializable if the specified
- * sorted map is serializable.
- *
- * @param m the sorted map to be "wrapped" in a synchronized sorted map.
- * @return a synchronized view of the specified sorted map.
- */
- public static SortedMap synchronizedSortedMap(SortedMap m) {
- return new SynchronizedSortedMap<>(m);
- }
-
-
- /**
- * @serial include
- */
- static class SynchronizedSortedMap
- extends SynchronizedMap
- implements SortedMap
- {
- private static final long serialVersionUID = -8798146769416483793L;
-
- private final SortedMap sm;
-
- SynchronizedSortedMap(SortedMap m) {
- super(m);
- sm = m;
- }
- SynchronizedSortedMap(SortedMap m, Object mutex) {
- super(m, mutex);
- sm = m;
- }
-
- public Comparator comparator() {
- synchronized (mutex) {return sm.comparator();}
- }
-
- public SortedMap subMap(K fromKey, K toKey) {
- synchronized (mutex) {
- return new SynchronizedSortedMap<>(
- sm.subMap(fromKey, toKey), mutex);
- }
- }
- public SortedMap headMap(K toKey) {
- synchronized (mutex) {
- return new SynchronizedSortedMap<>(sm.headMap(toKey), mutex);
- }
- }
- public SortedMap tailMap(K fromKey) {
- synchronized (mutex) {
- return new SynchronizedSortedMap<>(sm.tailMap(fromKey),mutex);
- }
- }
-
- public K firstKey() {
- synchronized (mutex) {return sm.firstKey();}
- }
- public K lastKey() {
- synchronized (mutex) {return sm.lastKey();}
- }
- }
-
- // Dynamically typesafe collection wrappers
-
- /**
- * Returns a dynamically typesafe view of the specified collection.
- * Any attempt to insert an element of the wrong type will result in an
- * immediate {@link ClassCastException}. Assuming a collection
- * contains no incorrectly typed elements prior to the time a
- * dynamically typesafe view is generated, and that all subsequent
- * access to the collection takes place through the view, it is
- * guaranteed that the collection cannot contain an incorrectly
- * typed element.
- *
- * The generics mechanism in the language provides compile-time
- * (static) type checking, but it is possible to defeat this mechanism
- * with unchecked casts. Usually this is not a problem, as the compiler
- * issues warnings on all such unchecked operations. There are, however,
- * times when static type checking alone is not sufficient. For example,
- * suppose a collection is passed to a third-party library and it is
- * imperative that the library code not corrupt the collection by
- * inserting an element of the wrong type.
- *
- *
Another use of dynamically typesafe views is debugging. Suppose a
- * program fails with a {@code ClassCastException}, indicating that an
- * incorrectly typed element was put into a parameterized collection.
- * Unfortunately, the exception can occur at any time after the erroneous
- * element is inserted, so it typically provides little or no information
- * as to the real source of the problem. If the problem is reproducible,
- * one can quickly determine its source by temporarily modifying the
- * program to wrap the collection with a dynamically typesafe view.
- * For example, this declaration:
- *
{@code
- * Collection c = new HashSet();
- * }
- * may be replaced temporarily by this one:
- * {@code
- * Collection c = Collections.checkedCollection(
- * new HashSet(), String.class);
- * }
- * Running the program again will cause it to fail at the point where
- * an incorrectly typed element is inserted into the collection, clearly
- * identifying the source of the problem. Once the problem is fixed, the
- * modified declaration may be reverted back to the original.
- *
- * The returned collection does not pass the hashCode and equals
- * operations through to the backing collection, but relies on
- * {@code Object}'s {@code equals} and {@code hashCode} methods. This
- * is necessary to preserve the contracts of these operations in the case
- * that the backing collection is a set or a list.
- *
- *
The returned collection will be serializable if the specified
- * collection is serializable.
- *
- *
Since {@code null} is considered to be a value of any reference
- * type, the returned collection permits insertion of null elements
- * whenever the backing collection does.
- *
- * @param c the collection for which a dynamically typesafe view is to be
- * returned
- * @param type the type of element that {@code c} is permitted to hold
- * @return a dynamically typesafe view of the specified collection
- * @since 1.5
- */
- public static Collection checkedCollection(Collection c,
- Class type) {
- return new CheckedCollection<>(c, type);
- }
-
- @SuppressWarnings("unchecked")
- static T[] zeroLengthArray(Class type) {
- return (T[]) Array.newInstance(type, 0);
- }
-
- /**
- * @serial include
- */
- static class CheckedCollection implements Collection, Serializable {
- private static final long serialVersionUID = 1578914078182001775L;
-
- final Collection c;
- final Class type;
-
- void typeCheck(Object o) {
- if (o != null && !type.isInstance(o))
- throw new ClassCastException(badElementMsg(o));
- }
-
- private String badElementMsg(Object o) {
- return "Attempt to insert " + o.getClass() +
- " element into collection with element type " + type;
- }
-
- CheckedCollection(Collection c, Class type) {
- if (c==null || type == null)
- throw new NullPointerException();
- this.c = c;
- this.type = type;
- }
-
- public int size() { return c.size(); }
- public boolean isEmpty() { return c.isEmpty(); }
- public boolean contains(Object o) { return c.contains(o); }
- public Object[] toArray() { return c.toArray(); }
- public T[] toArray(T[] a) { return c.toArray(a); }
- public String toString() { return c.toString(); }
- public boolean remove(Object o) { return c.remove(o); }
- public void clear() { c.clear(); }
-
- public boolean containsAll(Collection coll) {
- return c.containsAll(coll);
- }
- public boolean removeAll(Collection coll) {
- return c.removeAll(coll);
- }
- public boolean retainAll(Collection coll) {
- return c.retainAll(coll);
- }
-
- public Iterator iterator() {
- final Iterator it = c.iterator();
- return new Iterator() {
- public boolean hasNext() { return it.hasNext(); }
- public E next() { return it.next(); }
- public void remove() { it.remove(); }};
- }
-
- public boolean add(E e) {
- typeCheck(e);
- return c.add(e);
- }
-
- private E[] zeroLengthElementArray = null; // Lazily initialized
-
- private E[] zeroLengthElementArray() {
- return zeroLengthElementArray != null ? zeroLengthElementArray :
- (zeroLengthElementArray = zeroLengthArray(type));
- }
-
- @SuppressWarnings("unchecked")
- Collection checkedCopyOf(Collection coll) {
- Object[] a = null;
- try {
- E[] z = zeroLengthElementArray();
- a = coll.toArray(z);
- // Defend against coll violating the toArray contract
- if (a.getClass() != z.getClass())
- a = Arrays.copyOf(a, a.length, z.getClass());
- } catch (ArrayStoreException ignore) {
- // To get better and consistent diagnostics,
- // we call typeCheck explicitly on each element.
- // We call clone() to defend against coll retaining a
- // reference to the returned array and storing a bad
- // element into it after it has been type checked.
- a = coll.toArray().clone();
- for (Object o : a)
- typeCheck(o);
- }
- // A slight abuse of the type system, but safe here.
- return (Collection) Arrays.asList(a);
- }
-
- public boolean addAll(Collection coll) {
- // Doing things this way insulates us from concurrent changes
- // in the contents of coll and provides all-or-nothing
- // semantics (which we wouldn't get if we type-checked each
- // element as we added it)
- return c.addAll(checkedCopyOf(coll));
- }
- }
-
- /**
- * Returns a dynamically typesafe view of the specified set.
- * Any attempt to insert an element of the wrong type will result in
- * an immediate {@link ClassCastException}. Assuming a set contains
- * no incorrectly typed elements prior to the time a dynamically typesafe
- * view is generated, and that all subsequent access to the set
- * takes place through the view, it is guaranteed that the
- * set cannot contain an incorrectly typed element.
- *
- * A discussion of the use of dynamically typesafe views may be
- * found in the documentation for the {@link #checkedCollection
- * checkedCollection} method.
- *
- *
The returned set will be serializable if the specified set is
- * serializable.
- *
- *
Since {@code null} is considered to be a value of any reference
- * type, the returned set permits insertion of null elements whenever
- * the backing set does.
- *
- * @param s the set for which a dynamically typesafe view is to be
- * returned
- * @param type the type of element that {@code s} is permitted to hold
- * @return a dynamically typesafe view of the specified set
- * @since 1.5
- */
- public static Set checkedSet(Set s, Class type) {
- return new CheckedSet<>(s, type);
- }
-
- /**
- * @serial include
- */
- static class CheckedSet extends CheckedCollection
- implements Set, Serializable
- {
- private static final long serialVersionUID = 4694047833775013803L;
-
- CheckedSet(Set s, Class elementType) { super(s, elementType); }
-
- public boolean equals(Object o) { return o == this || c.equals(o); }
- public int hashCode() { return c.hashCode(); }
- }
-
- /**
- * Returns a dynamically typesafe view of the specified sorted set.
- * Any attempt to insert an element of the wrong type will result in an
- * immediate {@link ClassCastException}. Assuming a sorted set
- * contains no incorrectly typed elements prior to the time a
- * dynamically typesafe view is generated, and that all subsequent
- * access to the sorted set takes place through the view, it is
- * guaranteed that the sorted set cannot contain an incorrectly
- * typed element.
- *
- * A discussion of the use of dynamically typesafe views may be
- * found in the documentation for the {@link #checkedCollection
- * checkedCollection} method.
- *
- *
The returned sorted set will be serializable if the specified sorted
- * set is serializable.
- *
- *
Since {@code null} is considered to be a value of any reference
- * type, the returned sorted set permits insertion of null elements
- * whenever the backing sorted set does.
- *
- * @param s the sorted set for which a dynamically typesafe view is to be
- * returned
- * @param type the type of element that {@code s} is permitted to hold
- * @return a dynamically typesafe view of the specified sorted set
- * @since 1.5
- */
- public static SortedSet checkedSortedSet(SortedSet s,
- Class type) {
- return new CheckedSortedSet<>(s, type);
- }
-
- /**
- * @serial include
- */
- static class CheckedSortedSet extends CheckedSet
- implements SortedSet, Serializable
- {
- private static final long serialVersionUID = 1599911165492914959L;
- private final SortedSet