| /* |
| * Copyright (c) 2000, 2006, 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 |
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| * questions. |
| */ |
| |
| package java.util; |
| |
| /** |
| * Marker interface used by <tt>List</tt> implementations to indicate that |
| * they support fast (generally constant time) random access. The primary |
| * purpose of this interface is to allow generic algorithms to alter their |
| * behavior to provide good performance when applied to either random or |
| * sequential access lists. |
| * |
| * <p>The best algorithms for manipulating random access lists (such as |
| * <tt>ArrayList</tt>) can produce quadratic behavior when applied to |
| * sequential access lists (such as <tt>LinkedList</tt>). Generic list |
| * algorithms are encouraged to check whether the given list is an |
| * <tt>instanceof</tt> this interface before applying an algorithm that would |
| * provide poor performance if it were applied to a sequential access list, |
| * and to alter their behavior if necessary to guarantee acceptable |
| * performance. |
| * |
| * <p>It is recognized that the distinction between random and sequential |
| * access is often fuzzy. For example, some <tt>List</tt> implementations |
| * provide asymptotically linear access times if they get huge, but constant |
| * access times in practice. Such a <tt>List</tt> implementation |
| * should generally implement this interface. As a rule of thumb, a |
| * <tt>List</tt> implementation should implement this interface if, |
| * for typical instances of the class, this loop: |
| * <pre> |
| * for (int i=0, n=list.size(); i < n; i++) |
| * list.get(i); |
| * </pre> |
| * runs faster than this loop: |
| * <pre> |
| * for (Iterator i=list.iterator(); i.hasNext(); ) |
| * i.next(); |
| * </pre> |
| * |
| * <p>This interface is a member of the |
| * <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
| * Java Collections Framework</a>. |
| * |
| * @since 1.4 |
| */ |
| public interface RandomAccess { |
| } |
