Java tutorial
//package com.java2s; /** * Copyright 2009 Welocalize, Inc. * * 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. * */ import java.util.Collection; import java.util.Iterator; import java.util.HashMap; public class Main { /** * Finds the difference between two HashMaps a and b. * Returns a HashMap containing elements in b that are not in a * * @return the difference as a HashMap */ public static HashMap hashMapDifference(HashMap a, HashMap b) { Iterator bKeyIterator = b.keySet().iterator(); Object key; Object value; HashMap difference = new HashMap(); while (bKeyIterator.hasNext()) { key = bKeyIterator.next(); if (!a.containsKey(key)) { value = b.get(key); difference.put(key, value); } } return difference; } /** * Returns the element at the specified position in the * collection. * Shifts any subsequent elements to the left * (subtracts one from their indices). * Returns the element that was removed from the Collection. * @param p_collection a Collection * @param p_index index of element to return. * @returns the element at the specified position in the * collection. */ public static Object get(Collection p_collection, int p_index) { if (p_collection == null) { return null; } Iterator it = p_collection.iterator(); for (int i = 0; it.hasNext(); i++) { if (i == p_index) { return it.next(); } } return null; } }