1 /* 2 * $Id: CollectionUtil.java 1229087 2012-01-09 10:35:14Z mck $ 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 package org.apache.tiles.request.collection; 22 23 import java.util.Enumeration; 24 25 /** 26 * Utilities for requests. 27 * 28 * @version $Rev: 1064782 $ $Date: 2011-01-28 18:08:52 +0100 (Fri, 28 Jan 2011) $ 29 */ 30 public final class CollectionUtil { 31 32 /** 33 * Constructor. 34 */ 35 private CollectionUtil() { 36 37 } 38 39 /** 40 * Returns the string representation of the key. 41 * 42 * @param key The key. 43 * @return The string representation of the key. 44 * @throws IllegalArgumentException If the key is <code>null</code>. 45 */ 46 public static String key(Object key) { 47 if (key == null) { 48 throw new IllegalArgumentException(); 49 } else if (key instanceof String) { 50 return ((String) key); 51 } else { 52 return (key.toString()); 53 } 54 } 55 56 /** 57 * Returns the number of elements in an enumeration, by iterating it. 58 * 59 * @param keys The enumeration. 60 * @return The number of elements. 61 */ 62 public static int enumerationSize(Enumeration<?> keys) { 63 int n = 0; 64 while (keys.hasMoreElements()) { 65 keys.nextElement(); 66 n++; 67 } 68 return n; 69 } 70 }