1 //
2 // ========================================================================
3 // Copyright (c) 1995-2016 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 /**
24 * A Container
25 */
26 public interface Container
27 {
28 /* ------------------------------------------------------------ */
29 /**
30 * Add a bean. If the bean is-a {@link Listener}, then also do an implicit {@link #addEventListener(Listener)}.
31 * @param o the bean object to add
32 * @return true if the bean was added, false if it was already present
33 */
34 public boolean addBean(Object o);
35
36 /**
37 * @return the list of beans known to this aggregate
38 * @see #getBean(Class)
39 */
40 public Collection<Object> getBeans();
41
42 /**
43 * @param clazz the class of the beans
44 * @return the list of beans of the given class (or subclass)
45 * @param <T> the Bean type
46 * @see #getBeans()
47 */
48 public <T> Collection<T> getBeans(Class<T> clazz);
49
50 /**
51 * @param clazz the class of the bean
52 * @return the first bean of a specific class (or subclass), or null if no such bean exist
53 * @param <T> the Bean type
54 */
55 public <T> T getBean(Class<T> clazz);
56
57 /**
58 * Removes the given bean.
59 * If the bean is-a {@link Listener}, then also do an implicit {@link #removeEventListener(Listener)}.
60 * @param o the bean to remove
61 * @return whether the bean was removed
62 */
63 public boolean removeBean(Object o);
64
65 /**
66 * Add an event listener.
67 * @see Container#addBean(Object)
68 * @param listener the listener to add
69 */
70 public void addEventListener(Listener listener);
71
72 /**
73 * Remove an event listener.
74 * @see Container#removeBean(Object)
75 * @param listener the listener to remove
76 */
77 public void removeEventListener(Listener listener);
78
79 /**
80 * A listener for Container events.
81 * If an added bean implements this interface it will receive the events
82 * for this container.
83 */
84 public interface Listener
85 {
86 void beanAdded(Container parent,Object child);
87 void beanRemoved(Container parent,Object child);
88 }
89
90 /**
91 * Inherited Listener.
92 * If an added bean implements this interface, then it will
93 * be added to all contained beans that are themselves Containers
94 */
95 public interface InheritedListener extends Listener
96 {
97 }
98 }