1 package org.apache.torque.util;
2
3 /*
4 * Copyright 2001-2004 The Apache Software Foundation.
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License")
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 import java.util.ArrayList;
20
21 /***
22 * List with unique entries. UniqueList does not allow null nor duplicates.
23 *
24 * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
25 * @version $Id: UniqueList.java,v 1.2.2.2 2004/05/20 04:36:06 seade Exp $
26 */
27 public class UniqueList extends ArrayList
28 {
29 /***
30 * Adds an Object to the list.
31 *
32 * @param o the Object to add
33 * @return true if the Object is added
34 */
35 public boolean add(Object o)
36 {
37 if (o != null && !contains(o))
38 {
39 return super.add(o);
40 }
41 return false;
42 }
43 }