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56 package org.objectstyle.cayenne.event;
57
58 import java.io.Serializable  ;
59
60 import org.apache.log4j.Logger;
61 import org.jgroups.Channel;
62 import org.jgroups.JChannel;
63 import org.jgroups.Message;
64 import org.jgroups.MessageListener;
65 import org.jgroups.blocks.PullPushAdapter;
66
67
74 public class JavaGroupsBridge extends EventBridge implements MessageListener {
75 private static Logger logObj = Logger.getLogger(JavaGroupsBridge.class);
76
77 protected byte[] state;
79
80 protected Channel channel;
81 protected PullPushAdapter adapter;
82 protected String multicastAddress;
83 protected String multicastPort;
84 protected String configURL;
85
86
89 public JavaGroupsBridge(EventSubject localSubject, String externalSubject) {
90 super(localSubject, externalSubject);
91 }
92
93 public String getConfigURL() {
94 return configURL;
95 }
96
97 public void setConfigURL(String configURL) {
98 this.configURL = configURL;
99 }
100
101 public String getMulticastAddress() {
102 return multicastAddress;
103 }
104
105 public void setMulticastAddress(String multicastAddress) {
106 this.multicastAddress = multicastAddress;
107 }
108
109 public String getMulticastPort() {
110 return multicastPort;
111 }
112
113 public void setMulticastPort(String multicastPort) {
114 this.multicastPort = multicastPort;
115 }
116
117 public byte[] getState() {
118 return state;
119 }
120
121 public void setState(byte[] state) {
122 this.state = state;
123 }
124
125
129 public void receive(Message message) {
130 try {
131 if (logObj.isDebugEnabled()) {
132 logObj.debug("Received Message from: " + message.getSrc());
133 }
134
135 CayenneEvent event = messageObjectToEvent((Serializable ) message.getObject());
136 if (event != null) {
137 if (logObj.isDebugEnabled()) {
138 logObj.debug("Received CayenneEvent: " + event.getClass().getName());
139 }
140
141 onExternalEvent(event);
142 }
143 } catch (Exception ex) {
144 logObj.info("Exception while processing message: ", ex);
145 }
146
147 }
148
149 protected void startupExternal() throws Exception {
150
153 if (configURL != null) {
156 logObj.debug("creating channel with configuration from " + configURL);
157 channel = new JChannel(configURL);
158 } else {
159 String configString = buildConfigString();
160 logObj.debug("creating channel with properties: " + configString);
161 channel = new JChannel(configString);
162 }
163
164 channel.setOpt(Channel.LOCAL, Boolean.FALSE);
166 channel.connect(externalSubject);
167 logObj.debug("channel connected.");
168
169 if (receivesExternalEvents()) {
170 adapter = new PullPushAdapter(channel, this);
171 }
172 }
173
174
178 protected String buildConfigString() {
179 if (multicastAddress == null) {
180 throw new IllegalStateException ("'multcastAddress' is not set");
181 }
182
183 if (multicastPort == null) {
184 throw new IllegalStateException ("'multcastPort' is not set");
185 }
186
187 return "UDP(mcast_addr="
188 + multicastAddress
189 + ";mcast_port="
190 + multicastPort
191 + ";ip_ttl=32):"
192 + "PING(timeout=3000;num_initial_members=6):"
193 + "FD(timeout=3000):"
194 + "VERIFY_SUSPECT(timeout=1500):"
195 + "pbcast.NAKACK(gc_lag=10;retransmit_timeout=600,1200,2400,4800):"
196 + "pbcast.STABLE(desired_avg_gossip=10000):"
197 + "FRAG:"
198 + "pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;"
199 + "shun=true;print_local_addr=false)";
200 }
201
202 protected void shutdownExternal() throws Exception {
203 try {
204 if (adapter != null) {
205 adapter.stop();
206 }
207
208 channel.close();
209 } finally {
210 adapter = null;
211 channel = null;
212 }
213 }
214
215 protected void sendExternalEvent(CayenneEvent localEvent) throws Exception {
216 logObj.debug("Sending event remotely: " + localEvent);
217 Message message = new Message(null, null, eventToMessageObject(localEvent));
218 channel.send(message);
219 }
220
221
226 protected Serializable eventToMessageObject(CayenneEvent event) throws Exception {
227 return event;
228 }
229
230
235 protected CayenneEvent messageObjectToEvent(Serializable object) throws Exception {
236 return (object instanceof CayenneEvent) ? (CayenneEvent) object : null;
237 }
238 }
239 |
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