10.3.1 Registering the Connector Server with the Jini Lookup Service

The following code extract is taken from the Server class in the Jini Lookup Service examples directory.

Example 10–6 Creating Connector Servers for Registration in the Jini Lookup Service

public class Server { 
   private final MBeanServer mbs; 
   private static boolean debug = false; 
   public Server() { 
     mbs = MBeanServerFactory.createMBeanServer(); 
   } 
 
  public JMXConnectorServer rmi(String url) 
      throws IOException, JMException, ClassNotFoundException { 
      JMXServiceURL jurl = new JMXServiceURL(url); 
      final HashMap env = new HashMap(); 
      // Environment map attributes 
     [...] 
     JMXConnectorServer rmis = 
        JMXConnectorServerFactory.newJMXConnectorServer(jurl, env, mbs); 
 
     final String agentName = System.getProperty("agent.name", 
                                                 "DefaultAgent"); 
 
     start(rmis,env,agentName); 
 
     return rmis; 
   } 
    
[...] 

Example 10–6 shows the creation of an MBean server mbs. As was the case for the SLP examples, the JMX service URL and the agent name are passed to Server when it is launched at the command line.

We then see the creation of an RMI connector server named rmis, using the system properties defined by the environment map env and the address jurl. The RMI connector server rmis is started. The RMI connector server address will be registered in the Jini lookup service under the name agentName. Subsequent code not shown here creates a corresponding JMXMP connector server named jmxmp, that will also be registered with the Jini lookup service, as shown in the following code extract.

Example 10–7 Registering the Connector Server with the Jini Lookup Service

public void start(JMXConnectorServer server, Map env, String agentName) 
      throws IOException, ClassNotFoundException { 
      server.start(); 
      final ServiceRegistrar registrar=getRegistrar(); 
      final JMXConnector proxy = server.toJMXConnector(env); 
      register(registrar,proxy,agentName); 
   } 
    
   public static ServiceRegistrar getRegistrar() 
      throws IOException, ClassNotFoundException, 
         MalformedURLException { 
      final String jurl = 
         System.getProperty("jini.lookup.url","jini://localhost"); 
      final LookupLocator lookup = new LookupLocator(jurl); 
      final ServiceRegistrar registrar = lookup.getRegistrar(); 
      if (registrar instanceof Administrable) 
          debug("Registry is administrable."); 
      return registrar; 
   } 
    
   public static ServiceRegistration register(ServiceRegistrar registrar, 
                                              JMXConnector proxy, 
                                              String name) 
      throws IOException { 
      Entry[] serviceAttrs = new Entry[] { 
              new net.jini.lookup.entry.Name(name) 
                       }; 
		        
      System.out.println("Registering proxy: AgentName=" + name ); 
      debug("" + proxy); 
      ServiceItem srvcItem = new ServiceItem(null, proxy, serviceAttrs); 
      ServiceRegistration srvcRegistration = 
             registrar.register(srvcItem, Lease.ANY); 
      debug("Registered ServiceID: " + 
                              srvcRegistration.getServiceID().toString()); 
      return srvcRegistration; 
   } 

Example 10–7 shows the creation of a connector server named server with the environment map env and the service URL jurl. The connector server instance server then gets a pointer to the Jini lookup service by calling the Jini lookup service method LookupLocator.getRegistrar().

The connector server is registered in the Jini lookup service in the form of a proxy, using the Jini lookup service locator registrar and the agent name under which the connector server will be registered. The proxy is in fact a client stub for the connector server, obtained by a call to the toJMXConnector() method of JMXConnectorServer.

The registration itself is performed by a call to the register() method of the Jini lookup service class ServiceRegistrar, with an array of service items.