1d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen// GenericsNote: Converted. 2d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen/* 3d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Copyright 2003-2004 The Apache Software Foundation 4d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 5d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Licensed under the Apache License, Version 2.0 (the "License"); 6d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * you may not use this file except in compliance with the License. 7d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * You may obtain a copy of the License at 8d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 9d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * http://www.apache.org/licenses/LICENSE-2.0 10d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 11d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Unless required by applicable law or agreed to in writing, software 12d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * distributed under the License is distributed on an "AS IS" BASIS, 13d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * See the License for the specific language governing permissions and 15d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * limitations under the License. 16d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 17d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chenpackage org.jivesoftware.smack.util.collections; 18d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 19d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chenimport java.util.Iterator; 20d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 21d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen/** 22d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Defines an iterator that operates over a <code>Map</code>. 23d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * <p/> 24d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * This iterator is a special version designed for maps. It can be more 25d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * efficient to use this rather than an entry set iterator where the option 26d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * is available, and it is certainly more convenient. 27d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * <p/> 28d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * A map that provides this interface may not hold the data internally using 29d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Map Entry objects, thus this interface can avoid lots of object creation. 30d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * <p/> 31d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * In use, this iterator iterates through the keys in the map. After each call 32d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * to <code>next()</code>, the <code>getValue()</code> method provides direct 33d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * access to the value. The value can also be set using <code>setValue()</code>. 34d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * <pre> 35d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * MapIterator it = map.mapIterator(); 36d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * while (it.hasNext()) { 37d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Object key = it.next(); 38d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Object value = it.getValue(); 39d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * it.setValue(newValue); 40d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * } 41d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * </pre> 42d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 43d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @author Matt Hall, John Watkinson, Stephen Colebourne 44d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:19 $ 45d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @since Commons Collections 3.0 46d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 47d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chenpublic interface MapIterator <K,V> extends Iterator<K> { 48d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 49d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen /** 50d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Checks to see if there are more entries still to be iterated. 51d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 52d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @return <code>true</code> if the iterator has more elements 53d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 54d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen boolean hasNext(); 55d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 56d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen /** 57d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Gets the next <em>key</em> from the <code>Map</code>. 58d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 59d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @return the next key in the iteration 60d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws java.util.NoSuchElementException 61d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * if the iteration is finished 62d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 63d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen K next(); 64d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 65d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen //----------------------------------------------------------------------- 66d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen /** 67d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Gets the current key, which is the key returned by the last call 68d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * to <code>next()</code>. 69d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 70d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @return the current key 71d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws IllegalStateException if <code>next()</code> has not yet been called 72d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 73d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen K getKey(); 74d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 75d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen /** 76d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Gets the current value, which is the value associated with the last key 77d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * returned by <code>next()</code>. 78d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 79d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @return the current value 80d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws IllegalStateException if <code>next()</code> has not yet been called 81d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 82d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen V getValue(); 83d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 84d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen //----------------------------------------------------------------------- 85d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen /** 86d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Removes the last returned key from the underlying <code>Map</code> (optional operation). 87d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * <p/> 88d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * This method can be called once per call to <code>next()</code>. 89d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 90d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws UnsupportedOperationException if remove is not supported by the map 91d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws IllegalStateException if <code>next()</code> has not yet been called 92d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws IllegalStateException if <code>remove()</code> has already been called 93d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * since the last call to <code>next()</code> 94d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 95d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen void remove(); 96d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 97d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen /** 98d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * Sets the value associated with the current key (optional operation). 99d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * 100d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @param value the new value 101d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @return the previous value 102d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws UnsupportedOperationException if setValue is not supported by the map 103d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws IllegalStateException if <code>next()</code> has not yet been called 104d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * @throws IllegalStateException if <code>remove()</code> has been called since the 105d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen * last call to <code>next()</code> 106d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen */ 107d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen V setValue(V value); 108d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen 109d7955ce24d294fb2014c59d11fca184471056f44Shuyi Chen} 110