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 }