1 | package omq.common.broker; |
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2 | |
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3 | import java.io.IOException; |
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4 | import java.lang.reflect.Proxy; |
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5 | import java.util.HashMap; |
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6 | import java.util.Hashtable; |
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7 | import java.util.Map; |
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8 | import java.util.Properties; |
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9 | |
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10 | import omq.Remote; |
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11 | import omq.client.listener.ResponseListener; |
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12 | import omq.client.proxy.MultiProxymq; |
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13 | import omq.client.proxy.Proxymq; |
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14 | import omq.common.util.OmqConnectionFactory; |
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15 | import omq.common.util.ParameterQueue; |
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16 | import omq.common.util.Serializer; |
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17 | import omq.exception.AlreadyBoundException; |
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18 | import omq.exception.InitBrokerException; |
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19 | import omq.exception.RemoteException; |
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20 | import omq.server.RemoteObject; |
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21 | import omq.supervisor.Supervisor; |
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22 | |
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23 | import org.apache.log4j.Logger; |
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24 | |
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25 | import com.rabbitmq.client.AMQP.BasicProperties; |
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26 | import com.rabbitmq.client.Channel; |
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27 | import com.rabbitmq.client.Connection; |
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28 | import com.rabbitmq.client.QueueingConsumer; |
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29 | import com.rabbitmq.client.QueueingConsumer.Delivery; |
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30 | import com.rabbitmq.client.ShutdownListener; |
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31 | import com.rabbitmq.client.ShutdownSignalException; |
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32 | |
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33 | /** |
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34 | * A "broker" allows a new connection to a RabbitMQ server. Under this |
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35 | * connection it can have binded object and proxies. |
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36 | * |
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37 | * @author Sergi Toda <sergi.toda@estudiants.urv.cat> |
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38 | * |
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39 | */ |
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40 | public class Broker { |
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41 | |
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42 | private static final Logger logger = Logger.getLogger(Broker.class.getName()); |
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43 | |
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44 | private Connection connection; |
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45 | private Channel channel; |
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46 | private ResponseListener responseListener; |
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47 | private Serializer serializer; |
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48 | private boolean clientStarted = false; |
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49 | private boolean connectionClosed = false; |
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50 | private Properties environment = null; |
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51 | private Map<String, RemoteObject> remoteObjs; |
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52 | private Map<String, Object> proxies = new Hashtable<String, Object>(); |
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53 | private Map<String, Object> multiProxies = new Hashtable<String, Object>(); |
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54 | |
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55 | // Supervisor |
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56 | private Supervisor supervisor; |
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57 | |
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58 | public Broker(Properties env) throws Exception { |
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59 | // Load log4j configuration |
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60 | // URL log4jResource = Broker.class.getResource("/log4j.xml"); |
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61 | // DOMConfigurator.configure(log4jResource); |
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62 | |
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63 | remoteObjs = new HashMap<String, RemoteObject>(); |
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64 | serializer = new Serializer(env); |
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65 | environment = env; |
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66 | connection = OmqConnectionFactory.getNewConnection(env); |
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67 | channel = connection.createChannel(); |
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68 | addFaultTolerance(); |
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69 | if (!connection.isOpen() || !channel.isOpen()) { |
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70 | if (connection.isOpen()) { |
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71 | connection.close(); |
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72 | } |
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73 | throw new InitBrokerException("The connection didn't work"); |
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74 | } |
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75 | |
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76 | // try { |
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77 | // tryConnection(env); |
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78 | // } catch (Exception e) { |
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79 | // channel.close(); |
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80 | // connection.close(); |
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81 | // throw new InitBrokerException("The connection didn't work"); |
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82 | // } |
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83 | } |
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84 | |
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85 | /** |
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86 | * This method stops the broker's connection and all the threads created |
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87 | * |
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88 | * @throws Exception |
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89 | */ |
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90 | public void stopBroker() throws Exception { |
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91 | logger.warn("Stopping broker"); |
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92 | // Stop the client |
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93 | if (clientStarted) { |
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94 | responseListener.kill(); |
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95 | // TODO proxies = null; ?? |
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96 | } |
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97 | // Stop all the remote objects working |
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98 | for (String reference : remoteObjs.keySet()) { |
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99 | unbind(reference); |
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100 | } |
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101 | |
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102 | // Close the connection once all the listeners are died |
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103 | closeConnection(); |
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104 | |
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105 | clientStarted = false; |
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106 | // connectionClosed = false; |
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107 | environment = null; |
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108 | remoteObjs = null; |
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109 | } |
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110 | |
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111 | /** |
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112 | * @return Broker's connection |
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113 | * @throws Exception |
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114 | */ |
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115 | public Connection getConnection() throws Exception { |
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116 | return connection; |
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117 | } |
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118 | |
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119 | /** |
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120 | * This method close the broker's connection |
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121 | * |
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122 | * @throws IOException |
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123 | */ |
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124 | public void closeConnection() throws IOException { |
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125 | logger.warn("Clossing connection"); |
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126 | connectionClosed = true; |
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127 | connection.close(); |
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128 | // connectionClosed = false; |
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129 | } |
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130 | |
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131 | /** |
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132 | * Return the broker's channel |
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133 | * |
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134 | * @return Broker's channel |
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135 | * @throws Exception |
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136 | */ |
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137 | public synchronized Channel getChannel() throws Exception { |
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138 | return channel; |
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139 | } |
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140 | |
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141 | /** |
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142 | * Creates a new channel using the Broker's connection |
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143 | * |
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144 | * @return newChannel |
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145 | * @throws IOException |
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146 | */ |
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147 | public synchronized Channel getNewChannel() throws IOException { |
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148 | return connection.createChannel(); |
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149 | } |
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150 | |
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151 | /** |
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152 | * Publishes a request using a thread safe channel -if the channel is closed |
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153 | * it tries to open it once |
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154 | * |
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155 | * @param exchange |
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156 | * @param routingKey |
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157 | * @param props |
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158 | * @param bytesRequest |
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159 | * @throws IOException |
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160 | */ |
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161 | public synchronized void publishMessge(String exchange, String routingKey, BasicProperties props, byte[] bytesRequest) |
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162 | throws IOException { |
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163 | if (!channel.isOpen()) { |
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164 | logger.error("Broker's channel is closed opening a new one", channel.getCloseReason()); |
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165 | channel = getNewChannel(); |
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166 | } |
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167 | channel.basicPublish(exchange, routingKey, props, bytesRequest); |
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168 | } |
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169 | |
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170 | /** |
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171 | * Returns the remote object for specified reference. |
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172 | * |
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173 | * @param reference |
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174 | * - Binding name |
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175 | * @param contract |
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176 | * - Remote Interface |
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177 | * @return newProxy |
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178 | * @throws RemoteException |
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179 | */ |
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180 | @SuppressWarnings("unchecked") |
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181 | public synchronized <T extends Remote> T lookup(String reference, Class<T> contract) throws RemoteException { |
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182 | try { |
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183 | |
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184 | if (!clientStarted) { |
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185 | initClient(); |
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186 | } |
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187 | |
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188 | if (!proxies.containsKey(reference)) { |
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189 | Proxymq proxy = new Proxymq(reference, contract, this); |
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190 | Class<?>[] array = { contract }; |
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191 | Object newProxy = Proxy.newProxyInstance(contract.getClassLoader(), array, proxy); |
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192 | proxies.put(reference, newProxy); |
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193 | return (T) newProxy; |
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194 | } |
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195 | return (T) proxies.get(reference); |
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196 | |
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197 | } catch (Exception e) { |
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198 | throw new RemoteException(e); |
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199 | } |
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200 | } |
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201 | |
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202 | /** |
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203 | * Returns the remote object for specified reference. This function returns |
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204 | * an special type of proxy, every method invoked will be multi and |
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205 | * asynchronous. |
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206 | * |
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207 | * @param reference |
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208 | * - Binding name |
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209 | * @param contract |
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210 | * - Remote Interface |
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211 | * @return newProxy |
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212 | * @throws RemoteException |
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213 | */ |
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214 | @SuppressWarnings("unchecked") |
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215 | public synchronized <T extends Remote> T lookupMulti(String reference, Class<T> contract) throws RemoteException { |
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216 | try { |
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217 | if (!multiProxies.containsKey(reference)) { |
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218 | MultiProxymq proxy = new MultiProxymq(reference, contract, this); |
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219 | Class<?>[] array = { contract }; |
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220 | Object newProxy = Proxy.newProxyInstance(contract.getClassLoader(), array, proxy); |
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221 | multiProxies.put(reference, newProxy); |
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222 | return (T) newProxy; |
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223 | } |
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224 | return (T) multiProxies.get(reference); |
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225 | |
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226 | } catch (Exception e) { |
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227 | throw new RemoteException(e); |
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228 | } |
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229 | } |
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230 | |
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231 | /** |
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232 | * Binds the reference to the specified remote object. This function uses |
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233 | * the broker's environment |
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234 | * |
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235 | * @param reference |
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236 | * - Binding name |
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237 | * @param remote |
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238 | * - RemoteObject to bind |
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239 | * @throws RemoteException |
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240 | * If the remote operation failed |
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241 | * @throws AlreadyBoundException |
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242 | * If name is already bound. |
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243 | */ |
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244 | public void bind(String reference, RemoteObject remote) throws RemoteException, AlreadyBoundException { |
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245 | bind(reference, remote, environment); |
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246 | } |
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247 | |
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248 | public void bind(String reference, String UID, RemoteObject remote) throws RemoteException, AlreadyBoundException { |
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249 | bind(reference, UID, remote, environment); |
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250 | } |
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251 | |
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252 | /** |
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253 | * Binds the reference to the specified remote object. This function uses |
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254 | * the broker's environment |
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255 | * |
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256 | * @param reference |
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257 | * - Binding name |
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258 | * @param remote |
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259 | * - RemoteObject to bind |
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260 | * @param env |
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261 | * - RemoteObject environment. You can set how many threads will |
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262 | * be listen to the reference, the multiqueue name and the |
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263 | * properties of the object queue and multiqueue |
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264 | * @throws RemoteException |
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265 | * If the remote operation failed |
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266 | * @throws AlreadyBoundException |
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267 | * If name is already bound. |
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268 | */ |
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269 | public void bind(String reference, RemoteObject remote, Properties env) throws RemoteException, AlreadyBoundException { |
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270 | if (remoteObjs.containsKey(reference)) { |
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271 | throw new AlreadyBoundException(reference); |
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272 | } |
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273 | // Try to start the remtoeObject listeners |
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274 | try { |
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275 | remote.startRemoteObject(reference, this, env); |
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276 | remoteObjs.put(reference, remote); |
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277 | } catch (Exception e) { |
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278 | throw new RemoteException(e); |
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279 | } |
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280 | } |
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281 | |
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282 | public void bind(String reference, String UID, RemoteObject remote, Properties env) throws RemoteException, AlreadyBoundException { |
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283 | if (remoteObjs.containsKey(reference)) { |
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284 | throw new AlreadyBoundException(reference); |
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285 | } |
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286 | // Try to start the remtoeObject listeners |
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287 | try { |
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288 | remote.startRemoteObject(reference, UID, this, env); |
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289 | remoteObjs.put(reference, remote); |
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290 | } catch (Exception e) { |
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291 | throw new RemoteException(e); |
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292 | } |
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293 | } |
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294 | |
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295 | /** |
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296 | * Unbinds a remoteObject from its reference and kills all the threads |
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297 | * created. |
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298 | * |
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299 | * @param reference |
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300 | * - Binding name |
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301 | * @throws RemoteException |
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302 | * If the remote operation failed |
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303 | * @throws IOException |
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304 | * If there are problems while killing the threads |
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305 | */ |
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306 | public void unbind(String reference) throws RemoteException, IOException { |
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307 | if (remoteObjs.containsKey(reference)) { |
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308 | RemoteObject remote = remoteObjs.get(reference); |
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309 | remote.kill(); |
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310 | remoteObjs.remove(reference); |
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311 | } else { |
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312 | throw new RemoteException("The object referenced by 'reference' does not exist in the Broker"); |
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313 | } |
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314 | |
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315 | } |
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316 | |
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317 | /** |
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318 | * This method ensures the client will have only one ResponseListener. |
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319 | * |
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320 | * @throws Exception |
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321 | */ |
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322 | private synchronized void initClient() throws Exception { |
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323 | if (responseListener == null) { |
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324 | responseListener = new ResponseListener(this); |
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325 | responseListener.start(); |
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326 | clientStarted = true; |
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327 | } |
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328 | } |
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329 | |
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330 | /** |
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331 | * This function is used to send a ping message to see if the connection |
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332 | * works |
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333 | * |
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334 | * @param env |
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335 | * @throws Exception |
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336 | */ |
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337 | public void tryConnection(Properties env) throws Exception { |
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338 | Channel channel = connection.createChannel(); |
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339 | String message = "ping"; |
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340 | |
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341 | String exchange = env.getProperty(ParameterQueue.USER_NAME) + "ping"; |
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342 | String queueName = exchange; |
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343 | String routingKey = "routingKey"; |
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344 | |
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345 | channel.exchangeDeclare(exchange, "direct"); |
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346 | channel.queueDeclare(queueName, false, false, false, null); |
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347 | channel.queueBind(queueName, exchange, routingKey); |
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348 | |
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349 | channel.basicPublish(exchange, routingKey, null, message.getBytes()); |
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350 | |
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351 | QueueingConsumer consumer = new QueueingConsumer(channel); |
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352 | |
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353 | channel.basicConsume(queueName, true, consumer); |
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354 | Delivery delivery = consumer.nextDelivery(1000); |
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355 | |
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356 | channel.exchangeDelete(exchange); |
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357 | channel.queueDelete(queueName); |
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358 | |
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359 | channel.close(); |
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360 | |
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361 | if (!message.equalsIgnoreCase(new String(delivery.getBody()))) { |
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362 | throw new IOException("Ping initialitzation has failed"); |
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363 | } |
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364 | } |
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365 | |
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366 | /** |
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367 | * This method adds a ShutdownListener to the Broker's connection. When this |
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368 | * connection falls, a new connection will be created and this will also |
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369 | * have the listener. |
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370 | */ |
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371 | private void addFaultTolerance() { |
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372 | connection.addShutdownListener(new ShutdownListener() { |
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373 | @Override |
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374 | public void shutdownCompleted(ShutdownSignalException cause) { |
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375 | logger.warn("Shutdown message received. Cause: " + cause.getMessage()); |
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376 | if (!connectionClosed) |
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377 | if (cause.isHardError()) { |
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378 | if (connection.isOpen()) { |
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379 | try { |
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380 | connection.close(); |
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381 | } catch (IOException e) { |
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382 | e.printStackTrace(); |
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383 | } |
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384 | } |
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385 | try { |
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386 | connection = OmqConnectionFactory.getNewWorkingConnection(environment); |
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387 | channel = connection.createChannel(); |
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388 | addFaultTolerance(); |
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389 | } catch (Exception e) { |
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390 | e.printStackTrace(); |
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391 | } |
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392 | } else { |
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393 | Channel channel = (Channel) cause.getReference(); |
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394 | if (channel.isOpen()) { |
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395 | try { |
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396 | channel.close(); |
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397 | } catch (IOException e) { |
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398 | e.printStackTrace(); |
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399 | } |
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400 | } |
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401 | } |
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402 | } |
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403 | }); |
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404 | } |
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405 | |
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406 | public Properties getEnvironment() { |
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407 | return environment; |
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408 | } |
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409 | |
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410 | public ResponseListener getResponseListener() { |
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411 | return responseListener; |
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412 | } |
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413 | |
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414 | public Serializer getSerializer() { |
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415 | return serializer; |
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416 | } |
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417 | |
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418 | public Map<String, RemoteObject> getRemoteObjs() { |
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419 | return remoteObjs; |
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420 | } |
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421 | |
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422 | /* |
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423 | * Supervisor |
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424 | */ |
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425 | public void setSupervisor(String supervisorName, String brokerSet, String brokerName) throws Exception { |
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426 | // Create a RemoteBrokerImpl |
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427 | bind(brokerSet, brokerName, new RemoteBrokerImpl()); |
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428 | // Subscribe broker |
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429 | supervisor = lookup(supervisorName, Supervisor.class); |
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430 | supervisor.subscribe(brokerSet, brokerName); |
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431 | logger.info("Supervisor set: " + supervisorName + ", BrokerSet: " + brokerSet + ", BrokerName: " + brokerName); |
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432 | } |
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433 | |
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434 | public Supervisor getSupervisor() { |
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435 | return supervisor; |
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436 | } |
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437 | } |
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