org.apache.openjpa.lib.util.collections.IterableMap Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.openjpa.lib.util.collections;
import java.util.Map;
/**
* Defines a map that can be iterated directly without needing to create an entry set.
*
* A map iterator is an efficient way of iterating over maps.
* There is no need to access the entry set or use Map Entry objects.
*
*
* IterableMap<String,Integer> map = new HashedMap<String,Integer>();
* MapIterator<String,Integer> it = map.mapIterator();
* while (it.hasNext()) {
* String key = it.next();
* Integer value = it.getValue();
* it.setValue(value + 1);
* }
*
*
* @param the type of the keys in this map
* @param the type of the values in this map
*
* @since 3.0
*/
public interface IterableMap extends Map {
/**
* @see Map#clear()
*/
void clear();
/**
* Note that the return type is Object, rather than V as in the Map interface.
* See the class Javadoc for further info.
*
* @param key key with which the specified value is to be associated
* @param value value to be associated with the specified key
* @return the previous value associated with key, or
* null if there was no mapping for key.
* (A null return can also indicate that the map
* previously associated null with key,
* if the implementation supports null values.)
* @see Map#put(Object, Object)
*/
V put(K key, V value);
/**
* @param t mappings to be stored in this map
* @see Map#putAll(Map)
*/
void putAll(Map t);
/**
* Obtains a MapIterator over the map.
*
* A map iterator is an efficient way of iterating over maps.
* There is no need to access the entry set or use Map Entry objects.
*
* IterableMap<String,Integer> map = new HashedMap<String,Integer>();
* MapIterator<String,Integer> it = map.mapIterator();
* while (it.hasNext()) {
* String key = it.next();
* Integer value = it.getValue();
* it.setValue(value + 1);
* }
*
*
* @return a map iterator
*/
MapIterator mapIterator();
}