1 //
2 // ========================================================================
3 // Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.util.component;
20
21 import java.util.Collection;
22
23 public interface Container
24 {
25 /* ------------------------------------------------------------ */
26 /**
27 * Add a bean. If the bean is-a {@link Listener}, then also do an implicit {@link #addEventListener(Listener)}.
28 * @param o the bean object to add
29 * @return true if the bean was added, false if it was already present
30 */
31 public boolean addBean(Object o);
32
33 /**
34 * @return the list of beans known to this aggregate
35 * @see #getBean(Class)
36 */
37 public Collection<Object> getBeans();
38
39 /**
40 * @param clazz the class of the beans
41 * @return the list of beans of the given class (or subclass)
42 * @see #getBeans()
43 */
44 public <T> Collection<T> getBeans(Class<T> clazz);
45
46 /**
47 * @param clazz the class of the bean
48 * @return the first bean of a specific class (or subclass), or null if no such bean exist
49 */
50 public <T> T getBean(Class<T> clazz);
51
52 /**
53 * Removes the given bean.
54 * If the bean is-a {@link Listener}, then also do an implicit {@link #removeEventListener(Listener)}.
55 * @return whether the bean was removed
56 * @see #removeBeans()
57 */
58 public boolean removeBean(Object o);
59
60 /**
61 * Add an event listener.
62 * @see Container#addBean(Object), which also adds listeners if the bean is-a Listener
63 * @param listener
64 */
65 public void addEventListener(Listener listener);
66
67 /**
68 * Remove an event listener.
69 * @see Container#removeBean(Object), which also adds listeners if the bean is-a Listener
70 * @param listener
71 */
72 public void removeEventListener(Listener listener);
73
74 /**
75 * A listener for Container events.
76 * If an added bean implements this interface it will receive the events
77 * for this container.
78 */
79 public interface Listener
80 {
81 void beanAdded(Container parent,Object child);
82 void beanRemoved(Container parent,Object child);
83 }
84
85 /**
86 * Inherited Listener.
87 * If an added bean implements this interface, then it will
88 * be added to all contained beans that are themselves Containers
89 */
90 public interface InheritedListener extends Listener
91 {
92 }
93 }