1 /* $Id: Delegator.java 4010 2005-12-14 02:07:16Z stack-sf $
2 *
3 * Created on Dec 12, 2005
4 *
5 * Copyright (C) 2005 Internet Archive.
6 *
7 * This file is part of the Heritrix Cluster Controller (crawler.archive.org).
8 *
9 * HCC is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser Public License as published by
11 * the Free Software Foundation; either version 2.1 of the License, or
12 * any later version.
13 *
14 * Heritrix is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Lesser Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser Public License
20 * along with Heritrix; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23 package org.archive.hcc.util;
24
25 import java.util.LinkedList;
26 import java.util.List;
27
28
29 public class Delegator {
30
31 public enum DelegatorPolicy {
32 ACCEPT_ALL, ACCEPT_FIRST
33 };
34
35 protected List<Delegatable> handlers = new LinkedList<Delegatable>();
36
37 protected DelegatorPolicy policy;
38
39 public Delegator() {
40 this(DelegatorPolicy.ACCEPT_FIRST);
41 }
42
43 public Delegator(DelegatorPolicy policy) {
44 this.policy = policy;
45 }
46
47 public boolean delegate(Object object) {
48 boolean consumedAtLeastOne = false;
49 for (Delegatable h : handlers) {
50 boolean accepted = h.delegate(object);
51 if (accepted) {
52 consumedAtLeastOne = true;
53 }
54 if (accepted && policy == DelegatorPolicy.ACCEPT_FIRST) {
55 return true;
56 }
57 }
58
59 return consumedAtLeastOne;
60
61 }
62
63 public void addDelegatable(Delegatable handler) {
64 this.handlers.add(handler);
65 }
66 }