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.EventListener;
22
23 /* ------------------------------------------------------------ */
24 /**
25 * The lifecycle interface for generic components.
26 * <br />
27 * Classes implementing this interface have a defined life cycle
28 * defined by the methods of this interface.
29 *
30 *
31 */
32 public interface LifeCycle
33 {
34 /* ------------------------------------------------------------ */
35 /**
36 * Starts the component.
37 * @throws Exception If the component fails to start
38 * @see #isStarted()
39 * @see #stop()
40 * @see #isFailed()
41 */
42 public void start()
43 throws Exception;
44
45 /* ------------------------------------------------------------ */
46 /**
47 * Stops the component.
48 * The component may wait for current activities to complete
49 * normally, but it can be interrupted.
50 * @exception Exception If the component fails to stop
51 * @see #isStopped()
52 * @see #start()
53 * @see #isFailed()
54 */
55 public void stop()
56 throws Exception;
57
58 /* ------------------------------------------------------------ */
59 /**
60 * @return true if the component is starting or has been started.
61 */
62 public boolean isRunning();
63
64 /* ------------------------------------------------------------ */
65 /**
66 * @return true if the component has been started.
67 * @see #start()
68 * @see #isStarting()
69 */
70 public boolean isStarted();
71
72 /* ------------------------------------------------------------ */
73 /**
74 * @return true if the component is starting.
75 * @see #isStarted()
76 */
77 public boolean isStarting();
78
79 /* ------------------------------------------------------------ */
80 /**
81 * @return true if the component is stopping.
82 * @see #isStopped()
83 */
84 public boolean isStopping();
85
86 /* ------------------------------------------------------------ */
87 /**
88 * @return true if the component has been stopped.
89 * @see #stop()
90 * @see #isStopping()
91 */
92 public boolean isStopped();
93
94 /* ------------------------------------------------------------ */
95 /**
96 * @return true if the component has failed to start or has failed to stop.
97 */
98 public boolean isFailed();
99
100 /* ------------------------------------------------------------ */
101 public void addLifeCycleListener(LifeCycle.Listener listener);
102
103 /* ------------------------------------------------------------ */
104 public void removeLifeCycleListener(LifeCycle.Listener listener);
105
106
107 /* ------------------------------------------------------------ */
108 /** Listener.
109 * A listener for Lifecycle events.
110 */
111 public interface Listener extends EventListener
112 {
113 public void lifeCycleStarting(LifeCycle event);
114 public void lifeCycleStarted(LifeCycle event);
115 public void lifeCycleFailure(LifeCycle event,Throwable cause);
116 public void lifeCycleStopping(LifeCycle event);
117 public void lifeCycleStopped(LifeCycle event);
118 }
119 }