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Diffstat (limited to 'src/org/jivesoftware/smack/util/collections/MapIterator.java')
-rw-r--r-- | src/org/jivesoftware/smack/util/collections/MapIterator.java | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/org/jivesoftware/smack/util/collections/MapIterator.java b/src/org/jivesoftware/smack/util/collections/MapIterator.java new file mode 100644 index 0000000..fe2398c --- /dev/null +++ b/src/org/jivesoftware/smack/util/collections/MapIterator.java @@ -0,0 +1,109 @@ +// GenericsNote: Converted. +/* + * Copyright 2003-2004 The Apache Software Foundation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.jivesoftware.smack.util.collections; + +import java.util.Iterator; + +/** + * Defines an iterator that operates over a <code>Map</code>. + * <p/> + * This iterator is a special version designed for maps. It can be more + * efficient to use this rather than an entry set iterator where the option + * is available, and it is certainly more convenient. + * <p/> + * A map that provides this interface may not hold the data internally using + * Map Entry objects, thus this interface can avoid lots of object creation. + * <p/> + * In use, this iterator iterates through the keys in the map. After each call + * to <code>next()</code>, the <code>getValue()</code> method provides direct + * access to the value. The value can also be set using <code>setValue()</code>. + * <pre> + * MapIterator it = map.mapIterator(); + * while (it.hasNext()) { + * Object key = it.next(); + * Object value = it.getValue(); + * it.setValue(newValue); + * } + * </pre> + * + * @author Matt Hall, John Watkinson, Stephen Colebourne + * @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:19 $ + * @since Commons Collections 3.0 + */ +public interface MapIterator <K,V> extends Iterator<K> { + + /** + * Checks to see if there are more entries still to be iterated. + * + * @return <code>true</code> if the iterator has more elements + */ + boolean hasNext(); + + /** + * Gets the next <em>key</em> from the <code>Map</code>. + * + * @return the next key in the iteration + * @throws java.util.NoSuchElementException + * if the iteration is finished + */ + K next(); + + //----------------------------------------------------------------------- + /** + * Gets the current key, which is the key returned by the last call + * to <code>next()</code>. + * + * @return the current key + * @throws IllegalStateException if <code>next()</code> has not yet been called + */ + K getKey(); + + /** + * Gets the current value, which is the value associated with the last key + * returned by <code>next()</code>. + * + * @return the current value + * @throws IllegalStateException if <code>next()</code> has not yet been called + */ + V getValue(); + + //----------------------------------------------------------------------- + /** + * Removes the last returned key from the underlying <code>Map</code> (optional operation). + * <p/> + * This method can be called once per call to <code>next()</code>. + * + * @throws UnsupportedOperationException if remove is not supported by the map + * @throws IllegalStateException if <code>next()</code> has not yet been called + * @throws IllegalStateException if <code>remove()</code> has already been called + * since the last call to <code>next()</code> + */ + void remove(); + + /** + * Sets the value associated with the current key (optional operation). + * + * @param value the new value + * @return the previous value + * @throws UnsupportedOperationException if setValue is not supported by the map + * @throws IllegalStateException if <code>next()</code> has not yet been called + * @throws IllegalStateException if <code>remove()</code> has been called since the + * last call to <code>next()</code> + */ + V setValue(V value); + +} |