1 /*
2 * Copyright (c) 1998-2002 The Jgroup Team.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU Lesser General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
16 *
17 */
18
19 package jgroup.test.hello;
20
21 import java.rmi.RemoteException;
22
23 import jgroup.core.GroupManager;
24 import jgroup.core.MemberId;
25 import jgroup.core.MembershipListener;
26 import jgroup.core.View;
27 import jgroup.core.protocols.Multicast;
28 import jgroup.util.Network;
29
30 /**
31 * Simple Hello server aimed at demonstrating the capabilities of both
32 * internal and external invocations. This server is modified to be used
33 * with the automatic join and bind of the PGMS and RegistryLayer, and to
34 * test things like the LeaseLayer and NotifyLayer.
35 *
36 * @author Alberto Montresor
37 * @author Hein Meling
38 * @since Jgroup 1.0
39 */
40 public class NotifyServer
41 implements Hello, InternalHello, MembershipListener
42 {
43
44 ////////////////////////////////////////////////////////////////////////////////////////////
45 // Fields
46 ////////////////////////////////////////////////////////////////////////////////////////////
47
48 /** Stores the answer for replying to external invocations */
49 private Answer answer;
50
51 /** The group manager reference */
52 private GroupManager gm = null;
53
54 /** Reference to the internal hello group proxy (for group internal invocations) */
55 private InternalHello internalHello;
56
57
58 ////////////////////////////////////////////////////////////////////////////////////////////
59 // Main method (initialize the NotifyServer object)
60 ////////////////////////////////////////////////////////////////////////////////////////////
61
62 public static void main(String argv[])
63 throws Exception
64 {
65 NotifyServer obj = new NotifyServer();
66 /*
67 * Note that, at this point we do not exit since the dependable
68 * registry reference holds a strong reference to this
69 * <code>NotifyServer</code> object, and thus prevents it from being
70 * garbage collected. This again prevents the server from exiting
71 * at this point. So, to stop the server from running we must
72 * either, use CTRL-C or unbind the helloserver reference in the
73 * dependable registry.
74 */
75 }
76
77
78 ////////////////////////////////////////////////////////////////////////////////////////////
79 // Constructor for the NotifyServer
80 ////////////////////////////////////////////////////////////////////////////////////////////
81
82 public NotifyServer()
83 throws Exception
84 {
85 System.out.println("Server starting...");
86 /* Prepare the answer for replying to external invocations. */
87 answer = new Answer("Hello from " + Network.getLocalHostName());
88
89 /* Obtain the group manager */
90 gm = GroupManager.getGroupManager(this);
91 System.out.println("Server obtained group manager");
92 }
93
94
95 ////////////////////////////////////////////////////////////////////////////////////////////
96 // Methods from the Hello interface (External Group Method Invocation)
97 ////////////////////////////////////////////////////////////////////////////////////////////
98
99 public Answer sayHello()
100 throws RemoteException
101 {
102 System.out.println("sayHello: returning " + answer);
103 return answer;
104 }
105
106 @Multicast public double doCompute() throws RemoteException
107 {
108 return 0;
109 }
110
111
112 ////////////////////////////////////////////////////////////////////////////////////////////
113 // Methods from the InternalHello interface (Internal Group Method Invocation)
114 ////////////////////////////////////////////////////////////////////////////////////////////
115
116 public Object time()
117 throws RemoteException
118 {
119 long tmp = System.currentTimeMillis();
120 System.out.println("Generating time: " + tmp);
121 return new Long(tmp);
122 }
123
124
125 ////////////////////////////////////////////////////////////////////////////////////////////
126 // Methods from MembershipListener
127 ////////////////////////////////////////////////////////////////////////////////////////////
128
129 public void viewChange(View view)
130 {
131 if (internalHello == null) {
132 /* Obtain the reference for this groups group manager */
133 gm = GroupManager.getGroupManager(view.getGid());
134 /* Obtain proxy for the internal hello service required by the NotifyServer */
135 internalHello = (InternalHello) gm.getService(InternalHello.class);
136 }
137
138 System.out.println("View id: " + view.getVid());
139 MemberId[] members = view.getMembers();
140 for (int i = 0; i < members.length; i++)
141 System.out.println("Member[" + i + "]: " + members[i]);
142
143 try {
144 /*
145 * The time() method is defined in the InternalHello interface and
146 * is marked as a group internal method. By definition, all group
147 * internal methods will return an array of values instead of a
148 * single value as with standard remote (or external group) method
149 * calls.
150 */
151 Object[] objs = (Object[]) internalHello.time();
152 for (int i = 0; i < objs.length; i++)
153 System.out.println("Time: " + objs[i]);
154 answer.setTime(objs);
155 } catch (Exception e) {
156 e.printStackTrace();
157 }
158 }
159
160 public void prepareChange()
161 {
162 }
163
164 public void hasLeft()
165 {
166 }
167
168 } // END NotifyServer