| |
| /* ==================================================================== |
| 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.poi.util; |
| |
| import java.util.*; |
| |
| /** |
| * A List of objects that are indexed AND keyed by an int; also allows for getting |
| * the index of a value in the list |
| * |
| * <p>I am happy is someone wants to re-implement this without using the |
| * internal list and hashmap. If so could you please make sure that |
| * you can add elements half way into the list and have the value-key mappings |
| * update</p> |
| * |
| * |
| * @author Jason Height |
| */ |
| |
| public class IntMapper<T> |
| { |
| private List<T> elements; |
| private Map<T,Integer> valueKeyMap; |
| |
| private static final int _default_size = 10; |
| |
| /** |
| * create an IntMapper of default size |
| */ |
| |
| public IntMapper() |
| { |
| this(_default_size); |
| } |
| |
| public IntMapper(final int initialCapacity) |
| { |
| elements = new ArrayList<T>(initialCapacity); |
| valueKeyMap = new HashMap<T,Integer>(initialCapacity); |
| } |
| |
| /** |
| * Appends the specified element to the end of this list |
| * |
| * @param value element to be appended to this list. |
| * |
| * @return true (as per the general contract of the Collection.add |
| * method). |
| */ |
| public boolean add(final T value) |
| { |
| int index = elements.size(); |
| elements.add(value); |
| valueKeyMap.put(value, index); |
| return true; |
| } |
| |
| public int size() { |
| return elements.size(); |
| } |
| |
| public T get(int index) { |
| return elements.get(index); |
| } |
| |
| public int getIndex(T o) { |
| Integer i = valueKeyMap.get(o); |
| if (i == null) |
| return -1; |
| return i.intValue(); |
| } |
| |
| public Iterator<T> iterator() { |
| return elements.iterator(); |
| } |
| } // end public class IntMapper |
| |