1.1 --- a/emul/compact/src/main/java/java/util/Collection.java Fri Mar 22 16:59:47 2013 +0100
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,456 +0,0 @@
1.4 -/*
1.5 - * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
1.6 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 - *
1.8 - * This code is free software; you can redistribute it and/or modify it
1.9 - * under the terms of the GNU General Public License version 2 only, as
1.10 - * published by the Free Software Foundation. Oracle designates this
1.11 - * particular file as subject to the "Classpath" exception as provided
1.12 - * by Oracle in the LICENSE file that accompanied this code.
1.13 - *
1.14 - * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 - * version 2 for more details (a copy is included in the LICENSE file that
1.18 - * accompanied this code).
1.19 - *
1.20 - * You should have received a copy of the GNU General Public License version
1.21 - * 2 along with this work; if not, write to the Free Software Foundation,
1.22 - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 - *
1.24 - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 - * or visit www.oracle.com if you need additional information or have any
1.26 - * questions.
1.27 - */
1.28 -
1.29 -package java.util;
1.30 -
1.31 -/**
1.32 - * The root interface in the <i>collection hierarchy</i>. A collection
1.33 - * represents a group of objects, known as its <i>elements</i>. Some
1.34 - * collections allow duplicate elements and others do not. Some are ordered
1.35 - * and others unordered. The JDK does not provide any <i>direct</i>
1.36 - * implementations of this interface: it provides implementations of more
1.37 - * specific subinterfaces like <tt>Set</tt> and <tt>List</tt>. This interface
1.38 - * is typically used to pass collections around and manipulate them where
1.39 - * maximum generality is desired.
1.40 - *
1.41 - * <p><i>Bags</i> or <i>multisets</i> (unordered collections that may contain
1.42 - * duplicate elements) should implement this interface directly.
1.43 - *
1.44 - * <p>All general-purpose <tt>Collection</tt> implementation classes (which
1.45 - * typically implement <tt>Collection</tt> indirectly through one of its
1.46 - * subinterfaces) should provide two "standard" constructors: a void (no
1.47 - * arguments) constructor, which creates an empty collection, and a
1.48 - * constructor with a single argument of type <tt>Collection</tt>, which
1.49 - * creates a new collection with the same elements as its argument. In
1.50 - * effect, the latter constructor allows the user to copy any collection,
1.51 - * producing an equivalent collection of the desired implementation type.
1.52 - * There is no way to enforce this convention (as interfaces cannot contain
1.53 - * constructors) but all of the general-purpose <tt>Collection</tt>
1.54 - * implementations in the Java platform libraries comply.
1.55 - *
1.56 - * <p>The "destructive" methods contained in this interface, that is, the
1.57 - * methods that modify the collection on which they operate, are specified to
1.58 - * throw <tt>UnsupportedOperationException</tt> if this collection does not
1.59 - * support the operation. If this is the case, these methods may, but are not
1.60 - * required to, throw an <tt>UnsupportedOperationException</tt> if the
1.61 - * invocation would have no effect on the collection. For example, invoking
1.62 - * the {@link #addAll(Collection)} method on an unmodifiable collection may,
1.63 - * but is not required to, throw the exception if the collection to be added
1.64 - * is empty.
1.65 - *
1.66 - * <p><a name="optional-restrictions"/>
1.67 - * Some collection implementations have restrictions on the elements that
1.68 - * they may contain. For example, some implementations prohibit null elements,
1.69 - * and some have restrictions on the types of their elements. Attempting to
1.70 - * add an ineligible element throws an unchecked exception, typically
1.71 - * <tt>NullPointerException</tt> or <tt>ClassCastException</tt>. Attempting
1.72 - * to query the presence of an ineligible element may throw an exception,
1.73 - * or it may simply return false; some implementations will exhibit the former
1.74 - * behavior and some will exhibit the latter. More generally, attempting an
1.75 - * operation on an ineligible element whose completion would not result in
1.76 - * the insertion of an ineligible element into the collection may throw an
1.77 - * exception or it may succeed, at the option of the implementation.
1.78 - * Such exceptions are marked as "optional" in the specification for this
1.79 - * interface.
1.80 - *
1.81 - * <p>It is up to each collection to determine its own synchronization
1.82 - * policy. In the absence of a stronger guarantee by the
1.83 - * implementation, undefined behavior may result from the invocation
1.84 - * of any method on a collection that is being mutated by another
1.85 - * thread; this includes direct invocations, passing the collection to
1.86 - * a method that might perform invocations, and using an existing
1.87 - * iterator to examine the collection.
1.88 - *
1.89 - * <p>Many methods in Collections Framework interfaces are defined in
1.90 - * terms of the {@link Object#equals(Object) equals} method. For example,
1.91 - * the specification for the {@link #contains(Object) contains(Object o)}
1.92 - * method says: "returns <tt>true</tt> if and only if this collection
1.93 - * contains at least one element <tt>e</tt> such that
1.94 - * <tt>(o==null ? e==null : o.equals(e))</tt>." This specification should
1.95 - * <i>not</i> be construed to imply that invoking <tt>Collection.contains</tt>
1.96 - * with a non-null argument <tt>o</tt> will cause <tt>o.equals(e)</tt> to be
1.97 - * invoked for any element <tt>e</tt>. Implementations are free to implement
1.98 - * optimizations whereby the <tt>equals</tt> invocation is avoided, for
1.99 - * example, by first comparing the hash codes of the two elements. (The
1.100 - * {@link Object#hashCode()} specification guarantees that two objects with
1.101 - * unequal hash codes cannot be equal.) More generally, implementations of
1.102 - * the various Collections Framework interfaces are free to take advantage of
1.103 - * the specified behavior of underlying {@link Object} methods wherever the
1.104 - * implementor deems it appropriate.
1.105 - *
1.106 - * <p>This interface is a member of the
1.107 - * <a href="{@docRoot}/../technotes/guides/collections/index.html">
1.108 - * Java Collections Framework</a>.
1.109 - *
1.110 - * @param <E> the type of elements in this collection
1.111 - *
1.112 - * @author Josh Bloch
1.113 - * @author Neal Gafter
1.114 - * @see Set
1.115 - * @see List
1.116 - * @see Map
1.117 - * @see SortedSet
1.118 - * @see SortedMap
1.119 - * @see HashSet
1.120 - * @see TreeSet
1.121 - * @see ArrayList
1.122 - * @see LinkedList
1.123 - * @see Vector
1.124 - * @see Collections
1.125 - * @see Arrays
1.126 - * @see AbstractCollection
1.127 - * @since 1.2
1.128 - */
1.129 -
1.130 -public interface Collection<E> extends Iterable<E> {
1.131 - // Query Operations
1.132 -
1.133 - /**
1.134 - * Returns the number of elements in this collection. If this collection
1.135 - * contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
1.136 - * <tt>Integer.MAX_VALUE</tt>.
1.137 - *
1.138 - * @return the number of elements in this collection
1.139 - */
1.140 - int size();
1.141 -
1.142 - /**
1.143 - * Returns <tt>true</tt> if this collection contains no elements.
1.144 - *
1.145 - * @return <tt>true</tt> if this collection contains no elements
1.146 - */
1.147 - boolean isEmpty();
1.148 -
1.149 - /**
1.150 - * Returns <tt>true</tt> if this collection contains the specified element.
1.151 - * More formally, returns <tt>true</tt> if and only if this collection
1.152 - * contains at least one element <tt>e</tt> such that
1.153 - * <tt>(o==null ? e==null : o.equals(e))</tt>.
1.154 - *
1.155 - * @param o element whose presence in this collection is to be tested
1.156 - * @return <tt>true</tt> if this collection contains the specified
1.157 - * element
1.158 - * @throws ClassCastException if the type of the specified element
1.159 - * is incompatible with this collection
1.160 - * (<a href="#optional-restrictions">optional</a>)
1.161 - * @throws NullPointerException if the specified element is null and this
1.162 - * collection does not permit null elements
1.163 - * (<a href="#optional-restrictions">optional</a>)
1.164 - */
1.165 - boolean contains(Object o);
1.166 -
1.167 - /**
1.168 - * Returns an iterator over the elements in this collection. There are no
1.169 - * guarantees concerning the order in which the elements are returned
1.170 - * (unless this collection is an instance of some class that provides a
1.171 - * guarantee).
1.172 - *
1.173 - * @return an <tt>Iterator</tt> over the elements in this collection
1.174 - */
1.175 - Iterator<E> iterator();
1.176 -
1.177 - /**
1.178 - * Returns an array containing all of the elements in this collection.
1.179 - * If this collection makes any guarantees as to what order its elements
1.180 - * are returned by its iterator, this method must return the elements in
1.181 - * the same order.
1.182 - *
1.183 - * <p>The returned array will be "safe" in that no references to it are
1.184 - * maintained by this collection. (In other words, this method must
1.185 - * allocate a new array even if this collection is backed by an array).
1.186 - * The caller is thus free to modify the returned array.
1.187 - *
1.188 - * <p>This method acts as bridge between array-based and collection-based
1.189 - * APIs.
1.190 - *
1.191 - * @return an array containing all of the elements in this collection
1.192 - */
1.193 - Object[] toArray();
1.194 -
1.195 - /**
1.196 - * Returns an array containing all of the elements in this collection;
1.197 - * the runtime type of the returned array is that of the specified array.
1.198 - * If the collection fits in the specified array, it is returned therein.
1.199 - * Otherwise, a new array is allocated with the runtime type of the
1.200 - * specified array and the size of this collection.
1.201 - *
1.202 - * <p>If this collection fits in the specified array with room to spare
1.203 - * (i.e., the array has more elements than this collection), the element
1.204 - * in the array immediately following the end of the collection is set to
1.205 - * <tt>null</tt>. (This is useful in determining the length of this
1.206 - * collection <i>only</i> if the caller knows that this collection does
1.207 - * not contain any <tt>null</tt> elements.)
1.208 - *
1.209 - * <p>If this collection makes any guarantees as to what order its elements
1.210 - * are returned by its iterator, this method must return the elements in
1.211 - * the same order.
1.212 - *
1.213 - * <p>Like the {@link #toArray()} method, this method acts as bridge between
1.214 - * array-based and collection-based APIs. Further, this method allows
1.215 - * precise control over the runtime type of the output array, and may,
1.216 - * under certain circumstances, be used to save allocation costs.
1.217 - *
1.218 - * <p>Suppose <tt>x</tt> is a collection known to contain only strings.
1.219 - * The following code can be used to dump the collection into a newly
1.220 - * allocated array of <tt>String</tt>:
1.221 - *
1.222 - * <pre>
1.223 - * String[] y = x.toArray(new String[0]);</pre>
1.224 - *
1.225 - * Note that <tt>toArray(new Object[0])</tt> is identical in function to
1.226 - * <tt>toArray()</tt>.
1.227 - *
1.228 - * @param a the array into which the elements of this collection are to be
1.229 - * stored, if it is big enough; otherwise, a new array of the same
1.230 - * runtime type is allocated for this purpose.
1.231 - * @return an array containing all of the elements in this collection
1.232 - * @throws ArrayStoreException if the runtime type of the specified array
1.233 - * is not a supertype of the runtime type of every element in
1.234 - * this collection
1.235 - * @throws NullPointerException if the specified array is null
1.236 - */
1.237 - <T> T[] toArray(T[] a);
1.238 -
1.239 - // Modification Operations
1.240 -
1.241 - /**
1.242 - * Ensures that this collection contains the specified element (optional
1.243 - * operation). Returns <tt>true</tt> if this collection changed as a
1.244 - * result of the call. (Returns <tt>false</tt> if this collection does
1.245 - * not permit duplicates and already contains the specified element.)<p>
1.246 - *
1.247 - * Collections that support this operation may place limitations on what
1.248 - * elements may be added to this collection. In particular, some
1.249 - * collections will refuse to add <tt>null</tt> elements, and others will
1.250 - * impose restrictions on the type of elements that may be added.
1.251 - * Collection classes should clearly specify in their documentation any
1.252 - * restrictions on what elements may be added.<p>
1.253 - *
1.254 - * If a collection refuses to add a particular element for any reason
1.255 - * other than that it already contains the element, it <i>must</i> throw
1.256 - * an exception (rather than returning <tt>false</tt>). This preserves
1.257 - * the invariant that a collection always contains the specified element
1.258 - * after this call returns.
1.259 - *
1.260 - * @param e element whose presence in this collection is to be ensured
1.261 - * @return <tt>true</tt> if this collection changed as a result of the
1.262 - * call
1.263 - * @throws UnsupportedOperationException if the <tt>add</tt> operation
1.264 - * is not supported by this collection
1.265 - * @throws ClassCastException if the class of the specified element
1.266 - * prevents it from being added to this collection
1.267 - * @throws NullPointerException if the specified element is null and this
1.268 - * collection does not permit null elements
1.269 - * @throws IllegalArgumentException if some property of the element
1.270 - * prevents it from being added to this collection
1.271 - * @throws IllegalStateException if the element cannot be added at this
1.272 - * time due to insertion restrictions
1.273 - */
1.274 - boolean add(E e);
1.275 -
1.276 - /**
1.277 - * Removes a single instance of the specified element from this
1.278 - * collection, if it is present (optional operation). More formally,
1.279 - * removes an element <tt>e</tt> such that
1.280 - * <tt>(o==null ? e==null : o.equals(e))</tt>, if
1.281 - * this collection contains one or more such elements. Returns
1.282 - * <tt>true</tt> if this collection contained the specified element (or
1.283 - * equivalently, if this collection changed as a result of the call).
1.284 - *
1.285 - * @param o element to be removed from this collection, if present
1.286 - * @return <tt>true</tt> if an element was removed as a result of this call
1.287 - * @throws ClassCastException if the type of the specified element
1.288 - * is incompatible with this collection
1.289 - * (<a href="#optional-restrictions">optional</a>)
1.290 - * @throws NullPointerException if the specified element is null and this
1.291 - * collection does not permit null elements
1.292 - * (<a href="#optional-restrictions">optional</a>)
1.293 - * @throws UnsupportedOperationException if the <tt>remove</tt> operation
1.294 - * is not supported by this collection
1.295 - */
1.296 - boolean remove(Object o);
1.297 -
1.298 -
1.299 - // Bulk Operations
1.300 -
1.301 - /**
1.302 - * Returns <tt>true</tt> if this collection contains all of the elements
1.303 - * in the specified collection.
1.304 - *
1.305 - * @param c collection to be checked for containment in this collection
1.306 - * @return <tt>true</tt> if this collection contains all of the elements
1.307 - * in the specified collection
1.308 - * @throws ClassCastException if the types of one or more elements
1.309 - * in the specified collection are incompatible with this
1.310 - * collection
1.311 - * (<a href="#optional-restrictions">optional</a>)
1.312 - * @throws NullPointerException if the specified collection contains one
1.313 - * or more null elements and this collection does not permit null
1.314 - * elements
1.315 - * (<a href="#optional-restrictions">optional</a>),
1.316 - * or if the specified collection is null.
1.317 - * @see #contains(Object)
1.318 - */
1.319 - boolean containsAll(Collection<?> c);
1.320 -
1.321 - /**
1.322 - * Adds all of the elements in the specified collection to this collection
1.323 - * (optional operation). The behavior of this operation is undefined if
1.324 - * the specified collection is modified while the operation is in progress.
1.325 - * (This implies that the behavior of this call is undefined if the
1.326 - * specified collection is this collection, and this collection is
1.327 - * nonempty.)
1.328 - *
1.329 - * @param c collection containing elements to be added to this collection
1.330 - * @return <tt>true</tt> if this collection changed as a result of the call
1.331 - * @throws UnsupportedOperationException if the <tt>addAll</tt> operation
1.332 - * is not supported by this collection
1.333 - * @throws ClassCastException if the class of an element of the specified
1.334 - * collection prevents it from being added to this collection
1.335 - * @throws NullPointerException if the specified collection contains a
1.336 - * null element and this collection does not permit null elements,
1.337 - * or if the specified collection is null
1.338 - * @throws IllegalArgumentException if some property of an element of the
1.339 - * specified collection prevents it from being added to this
1.340 - * collection
1.341 - * @throws IllegalStateException if not all the elements can be added at
1.342 - * this time due to insertion restrictions
1.343 - * @see #add(Object)
1.344 - */
1.345 - boolean addAll(Collection<? extends E> c);
1.346 -
1.347 - /**
1.348 - * Removes all of this collection's elements that are also contained in the
1.349 - * specified collection (optional operation). After this call returns,
1.350 - * this collection will contain no elements in common with the specified
1.351 - * collection.
1.352 - *
1.353 - * @param c collection containing elements to be removed from this collection
1.354 - * @return <tt>true</tt> if this collection changed as a result of the
1.355 - * call
1.356 - * @throws UnsupportedOperationException if the <tt>removeAll</tt> method
1.357 - * is not supported by this collection
1.358 - * @throws ClassCastException if the types of one or more elements
1.359 - * in this collection are incompatible with the specified
1.360 - * collection
1.361 - * (<a href="#optional-restrictions">optional</a>)
1.362 - * @throws NullPointerException if this collection contains one or more
1.363 - * null elements and the specified collection does not support
1.364 - * null elements
1.365 - * (<a href="#optional-restrictions">optional</a>),
1.366 - * or if the specified collection is null
1.367 - * @see #remove(Object)
1.368 - * @see #contains(Object)
1.369 - */
1.370 - boolean removeAll(Collection<?> c);
1.371 -
1.372 - /**
1.373 - * Retains only the elements in this collection that are contained in the
1.374 - * specified collection (optional operation). In other words, removes from
1.375 - * this collection all of its elements that are not contained in the
1.376 - * specified collection.
1.377 - *
1.378 - * @param c collection containing elements to be retained in this collection
1.379 - * @return <tt>true</tt> if this collection changed as a result of the call
1.380 - * @throws UnsupportedOperationException if the <tt>retainAll</tt> operation
1.381 - * is not supported by this collection
1.382 - * @throws ClassCastException if the types of one or more elements
1.383 - * in this collection are incompatible with the specified
1.384 - * collection
1.385 - * (<a href="#optional-restrictions">optional</a>)
1.386 - * @throws NullPointerException if this collection contains one or more
1.387 - * null elements and the specified collection does not permit null
1.388 - * elements
1.389 - * (<a href="#optional-restrictions">optional</a>),
1.390 - * or if the specified collection is null
1.391 - * @see #remove(Object)
1.392 - * @see #contains(Object)
1.393 - */
1.394 - boolean retainAll(Collection<?> c);
1.395 -
1.396 - /**
1.397 - * Removes all of the elements from this collection (optional operation).
1.398 - * The collection will be empty after this method returns.
1.399 - *
1.400 - * @throws UnsupportedOperationException if the <tt>clear</tt> operation
1.401 - * is not supported by this collection
1.402 - */
1.403 - void clear();
1.404 -
1.405 -
1.406 - // Comparison and hashing
1.407 -
1.408 - /**
1.409 - * Compares the specified object with this collection for equality. <p>
1.410 - *
1.411 - * While the <tt>Collection</tt> interface adds no stipulations to the
1.412 - * general contract for the <tt>Object.equals</tt>, programmers who
1.413 - * implement the <tt>Collection</tt> interface "directly" (in other words,
1.414 - * create a class that is a <tt>Collection</tt> but is not a <tt>Set</tt>
1.415 - * or a <tt>List</tt>) must exercise care if they choose to override the
1.416 - * <tt>Object.equals</tt>. It is not necessary to do so, and the simplest
1.417 - * course of action is to rely on <tt>Object</tt>'s implementation, but
1.418 - * the implementor may wish to implement a "value comparison" in place of
1.419 - * the default "reference comparison." (The <tt>List</tt> and
1.420 - * <tt>Set</tt> interfaces mandate such value comparisons.)<p>
1.421 - *
1.422 - * The general contract for the <tt>Object.equals</tt> method states that
1.423 - * equals must be symmetric (in other words, <tt>a.equals(b)</tt> if and
1.424 - * only if <tt>b.equals(a)</tt>). The contracts for <tt>List.equals</tt>
1.425 - * and <tt>Set.equals</tt> state that lists are only equal to other lists,
1.426 - * and sets to other sets. Thus, a custom <tt>equals</tt> method for a
1.427 - * collection class that implements neither the <tt>List</tt> nor
1.428 - * <tt>Set</tt> interface must return <tt>false</tt> when this collection
1.429 - * is compared to any list or set. (By the same logic, it is not possible
1.430 - * to write a class that correctly implements both the <tt>Set</tt> and
1.431 - * <tt>List</tt> interfaces.)
1.432 - *
1.433 - * @param o object to be compared for equality with this collection
1.434 - * @return <tt>true</tt> if the specified object is equal to this
1.435 - * collection
1.436 - *
1.437 - * @see Object#equals(Object)
1.438 - * @see Set#equals(Object)
1.439 - * @see List#equals(Object)
1.440 - */
1.441 - boolean equals(Object o);
1.442 -
1.443 - /**
1.444 - * Returns the hash code value for this collection. While the
1.445 - * <tt>Collection</tt> interface adds no stipulations to the general
1.446 - * contract for the <tt>Object.hashCode</tt> method, programmers should
1.447 - * take note that any class that overrides the <tt>Object.equals</tt>
1.448 - * method must also override the <tt>Object.hashCode</tt> method in order
1.449 - * to satisfy the general contract for the <tt>Object.hashCode</tt> method.
1.450 - * In particular, <tt>c1.equals(c2)</tt> implies that
1.451 - * <tt>c1.hashCode()==c2.hashCode()</tt>.
1.452 - *
1.453 - * @return the hash code value for this collection
1.454 - *
1.455 - * @see Object#hashCode()
1.456 - * @see Object#equals(Object)
1.457 - */
1.458 - int hashCode();
1.459 -}