1 /*
2 * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26
27 package com.sun.jmx.snmp.daemon;
28
29
30
31 /**
32 * Defines generic behaviour for the server
33 * part of a connector or an adaptor. Most connectors or adaptors extend <CODE>CommunicatorServer</CODE>
34 * and inherit this behaviour. Connectors or adaptors that do not fit into this model do not extend
35 * <CODE>CommunicatorServer</CODE>.
36 * <p>
37 * An <CODE>CommunicatorServer</CODE> is an active object, it listens for client requests
38 * and processes them in its own thread. When necessary, a <CODE>CommunicatorServer</CODE>
39 * creates other threads to process multiple requests concurrently.
40 * <p>
41 * A <CODE>CommunicatorServer</CODE> object can be stopped by calling the <CODE>stop</CODE>
42 * method. When it is stopped, the <CODE>CommunicatorServer</CODE> no longer listens to client
43 * requests and no longer holds any thread or communication resources.
44 * It can be started again by calling the <CODE>start</CODE> method.
45 * <p>
46 * A <CODE>CommunicatorServer</CODE> has a <CODE>state</CODE> property which reflects its
47 * activity.
48 * <p>
49 * <TABLE>
50 * <TR><TH>CommunicatorServer</TH> <TH>State</TH></TR>
51 * <TR><TD><CODE>stopped</CODE></TD> <TD><CODE>OFFLINE</CODE></TD></TR>
52 * <TR><TD><CODE>starting</CODE></TD> <TD><CODE>STARTING</CODE></TD></TR>
53 * <TR><TD><CODE>running</CODE></TD> <TD><CODE>ONLINE</CODE></TD></TR>
54 * <TR><TD><CODE>stopping</CODE></TD> <TD><CODE>STOPPING</CODE></TD></TR>
55 * </TABLE>
56 * <p>
57 * The <CODE>STARTING</CODE> state marks the transition from <CODE>OFFLINE</CODE> to
58 * <CODE>ONLINE</CODE>.
59 * <p>
60 * The <CODE>STOPPING</CODE> state marks the transition from <CODE>ONLINE</CODE> to
61 * <CODE>OFFLINE</CODE>. This occurs when the <CODE>CommunicatorServer</CODE> is
62 * finishing or interrupting active requests.
63 * <p>
64 * A <CODE>CommunicatorServer</CODE> may serve several clients concurrently. The
65 * number of concurrent clients can be limited using the property
66 * <CODE>maxActiveClientCount</CODE>. The default value of this property is
67 * defined by the subclasses.
68 * <p>
69 * When a <CODE>CommunicatorServer</CODE> is unregistered from the MBeanServer,
70 * it is stopped automatically.
71 *
72 * <p><b>This API is a Sun Microsystems internal API and is subject
73 * to change without notice.</b></p>
74 */
75
76 public interface CommunicatorServerMBean {
77
78 /**
79 * Starts this <CODE>CommunicatorServer</CODE>.
80 * <p>
81 * Has no effect if this <CODE>CommunicatorServer</CODE> is <CODE>ONLINE</CODE> or
82 * <CODE>STOPPING</CODE>.
83 */
84 public void start() ;
85
86 /**
87 * Stops this <CODE>CommunicatorServer</CODE>.
88 * <p>
89 * Has no effect if this <CODE>CommunicatorServer</CODE> is <CODE>OFFLINE</CODE> or
90 * <CODE>STOPPING</CODE>.
91 */
92 public void stop() ;
93
94 /**
95 * Tests if the <CODE>CommunicatorServer</CODE> is active.
96 *
97 * @return True if connector is <CODE>ONLINE</CODE>; false otherwise.
98 */
99 public boolean isActive() ;
100
101 /**
102 * Waits untill either the State attribute of this MBean equals the specified <VAR>state</VAR> parameter,
103 * or the specified <VAR>timeOut</VAR> has elapsed. The method <CODE>waitState</CODE> returns with a boolean value indicating whether
104 * the specified <VAR>state</VAR> parameter equals the value of this MBean's State attribute at the time the method terminates.
105 *
106 * Two special cases for the <VAR>timeOut</VAR> parameter value are:
107 * <UL><LI> if <VAR>timeOut</VAR> is negative then <CODE>waitState</CODE> returns immediately (i.e. does not wait at all),</LI>
108 * <LI> if <VAR>timeOut</VAR> equals zero then <CODE>waitState</CODE> waits untill the value of this MBean's State attribute
109 * is the same as the <VAR>state</VAR> parameter (i.e. will wait indefinitely if this condition is never met).</LI></UL>
110 *
111 * @param state The value of this MBean's State attribute
112 * to wait for. <VAR>state</VAR> can be one of:
113 * <ul>
114 * <li><CODE>CommunicatorServer.OFFLINE</CODE>,</li>
115 * <li><CODE>CommunicatorServer.ONLINE</CODE>,</li>
116 * <li><CODE>CommunicatorServer.STARTING</CODE>,</li>
117 * <li><CODE>CommunicatorServer.STOPPING</CODE>.</li>
118 * </ul>
119 * @param timeOut The maximum time to wait for, in
120 * milliseconds, if positive.
121 * Infinite time out if 0, or no waiting at all if negative.
122 *
123 * @return true if the value of this MBean's State attribute is the
124 * same as the <VAR>state</VAR> parameter; false otherwise.
125 */
126 public boolean waitState(int state , long timeOut) ;
127
128 /**
129 * Gets the state of this <CODE>CommunicatorServer</CODE> as an integer.
130 *
131 * @return <CODE>ONLINE</CODE>, <CODE>OFFLINE</CODE>, <CODE>STARTING</CODE> or <CODE>STOPPING</CODE>.
132 */
133 public int getState() ;
134
135 /**
136 * Gets the state of this <CODE>CommunicatorServer</CODE> as a string.
137 *
138 * @return One of the strings "ONLINE", "OFFLINE", "STARTING" or "STOPPING".
139 */
140 public String getStateString() ;
141
142 /**
143 * Gets the host name used by this <CODE>CommunicatorServer</CODE>.
144 *
145 * @return The host name used by this <CODE>CommunicatorServer</CODE>.
146 */
147 public String getHost() ;
148
149 /**
150 * Gets the port number used by this <CODE>CommunicatorServer</CODE>.
151 *
152 * @return The port number used by this <CODE>CommunicatorServer</CODE>.
153 */
154 public int getPort() ;
155
156 /**
157 * Sets the port number used by this <CODE>CommunicatorServer</CODE>.
158 *
159 * @param port The port number used by this <CODE>CommunicatorServer</CODE>.
160 *
161 * @exception java.lang.IllegalStateException This method has been invoked
162 * while the communicator was ONLINE or STARTING.
163 */
164 public void setPort(int port) throws java.lang.IllegalStateException ;
165
166 /**
167 * Gets the protocol being used by this <CODE>CommunicatorServer</CODE>.
168 * @return The protocol as a string.
169 */
170 public abstract String getProtocol() ;
171 }