2. Start the Server.

   The command you use to start the Server varies according to which external directory you are using. You can start one or more of the following instances of Server with different transports and external registries before starting the Client.

   2. RMI connector over JRMP, without an external directory.

      Start Server by typing the following command:

       
      $ java -classpath .:$classp -Ddebug=true \ 
        -Dagent.name=test-server-a \ 
        -Durl="service:jmx:rmi://" \ 
        -Djava.security.policy=java.policy \ 
        jini.Server & 
       
      

      In this command:

      • debug is set to true to provide more complete screen output when the Server runs.

      • The security policy is provided, to allow access to the Jini lookup service.

      • The name of the agent to be created is test-server-a.

      • The service URL specifies that the chosen connector is an RMI connector, running over the RMI default transport JRMP.

      When Server is launched, you will see confirmation of the creation of the RMI connector, and the registration of its URL in the Jini lookup service.

   3. RMI connector over JRMP, using an RMI registry as an external directory.

      Start Server by typing the following command:

       
      $ java -classpath .:$classp -Ddebug=true \ 
        -Dagent.name=test-server-b \ 
        -Durl="service:jmx:rmi:///jndi/${jndirmi}/server" \ 
        -Djava.security.policy=java.policy \ 
        jini.Server & 
       
      

      In this command:

      • The security policy is provided, to allow access to the Jini lookup service.

      • The name of the agent created is test-server-b.

      • The service URL specifies the chosen connector as RMI over JRMP, and the external directory in which the RMI connector stub, server, is stored is the RMI registry you identified as jndirmi in Section 4.1 "Initial Configuration".

      When Server is launched, you will see confirmation of the creation of the RMI connector, and the registration of its URL in the Jini lookup service.

   4. RMI connector over JRMP, using LDAP as the external directory.

      Start Server by typing the following command:

       
      $ java -classpath .:$classp -Ddebug=true \ 
        -Dagent.name=test-server-c \ 
        -Durl="service:jmx:rmi:///jndi/${jndildap}/cn=x,dc=Test" \ 
        -Djava.security.policy=java.policy \ 
        -Djava.naming.security.principal="$principal" \ 
        -Djava.naming.security.credentials="$credentials" \ 
        jini.Server & 
       
      

      In this command:

      • The security policy is provided, to allow access to the Jini lookup service.

      • The name of the agent created is test-server-c.The service URL specifies the chosen connector as RMI over JRMP, and the external directory in which the RMI connector stub is stored is the LDAP server you identified as jndildap in Section 4.1 "Initial Configuration".

      • The stub is registered in the Test domain component in the LDAP server.

      • The common name attribute principal and password credentials are given to gain access to the LDAP server.

      When Server is launched, you will see confirmation of the creation of the RMI connector, and the registration of its URL in the Jini lookup service under the agent name test-server-c.

   5. RMI connector over IIOP, without an external directory.

      Start Server by typing the following command:

       
      $ java -classpath .:$classp -Ddebug=true \ 
        -Dagent.name=test-server-d \ 
        -Durl="service:jmx:iiop://" \ 
        -Djava.security.policy=java.policy \ 
        jini.Server & 
       
      

      In this command:

      • The security policy is provided, to allow access to the Jini lookup service

      • The name of the agent created is test-server-d

      • The service URL specifies the chosen connector as RMI connector over IIOP.

      When the Server is launched, you will see confirmation of the creation of the RMI connector, and the registration of its automatically generated URL in the Jini lookup service.

   6. RMI connector over IIOP, using CORBA naming as the external directory.

      Start Server by typing the following command:

       
      $ java -classpath .:$classp -Ddebug=true \ 
        -Dagent.name=test-server-e \ 
        -Durl="service:jmx:iiop:///jndi/${jndiiiop}/server" \ 
        -Djava.security.policy=java.policy \ 
        jini.Server & 
       
      

      In this command:

      • The security policy is provided, to allow access to the Jini lookup service.

      • The name of the agent created is test-server-e.

      • The service URL specifies the chosen connector as RMI connector over IIOP. The external directory in which the RMI connector stub, server, is stored is the CORBA naming service you identified as jndiiiop in Section 4.1 "Initial Configuration".

      When Server is launched, you will see confirmation of the creation of the RMI connector, and the registration of its URL in the Jini lookup service under the name test-server-e.

   7. RMI connector over IIOP, using LDAP as the external directory.

      Start Server by typing the following command:

       
      $ java -classpath .:$classp -Ddebug=true \ 
        -Dagent.name=test-server-f \ 
        -Durl="service:jmx:iiop:///jndi/${jndildap}/cn=x,dc=Test" \ 
        -Djava.security.policy=java.policy \ 
        -Djava.naming.security.principal="$principal" \ 
        -Djava.naming.security.credentials="$credentials" \ 
        jini.Server & 
       
      

      In this command:

      • The security policy is provided, to allow access to the Jini lookup service.

      • The name of the agent created is test-server-f.

      • The service URL specifies the chosen connector as RMI over IIOP.

      • The external directory in which the RMI connector stub is stored is the LDAP server you identified as jndildap in Section 4.1 "Initial Configuration".

      • The stub is registered in the Test domain component in the LDAP server.

      • The common name attribute principal and password credentials are given to gain access to the LDAP server.

      When Server is launched, you will see confirmation of the creation of the RMI connector, and the registration of its URL in the Jini lookup service under the agent name test-server-f.

   • Start the Client.

   • After starting the Server using the transport and external directory of your choice, start the Client:

      
     $ java -classpath .:$classp -Ddebug=true \ 
       -Djava.security.policy=java.policy \ 
       jini.Client 
      
     

     You will see output confirming the detection of the agents created by the Server and registered in the lookup service. You will also see the identification and confirmation of the connection made to the agents.

     To look up a specific agent, you can do so by typing the following command:

      
     $ java -classpath .:$classp -Ddebug=true \ 
       -Djava.security.policy=java.policy \ 
       -Dagent.name=agentName \ 
       jini.Client 
      
     

     In the command shown above, agentName is the name of the agent you want to look up. You can also specify a partial agent name by using *; for example, x* for all agent names beginning with the letter x.

4.4 Java Naming and Directory Interface (JNDI) / LDAP Lookup Service

JMX technology allows you to register RMI connectors with a JNDI lookup service using an LDAP registry as a back end. This example performs the following operations:

The JNDI/LDAP lookup example is contained in the directory work_dir/jmx_examples/Lookup/ldap.

 
[...] 
 
public class Server { 
   public final static int JMX_DEFAULT_LEASE = 60; 
   private static boolean debug = false; 
   private final MBeanServer mbs; 
   public Server() { 
      mbs = MBeanServerFactory.createMBeanServer(); 
   } 
 
  public static DirContext getRootContext() throws NamingException { 
      final Hashtable env = new Hashtable(); 
 
      final String factory = 
        System.getProperty(Context.INITIAL_CONTEXT_FACTORY, 
                           "com.sun.jndi.ldap.LdapCtxFactory"); 
      final String ldapServerUrl = 
        System.getProperty(Context.PROVIDER_URL); 
      final String ldapUser = 
        System.getProperty(Context.SECURITY_PRINCIPAL, 
                           "cn=Directory Manager"); 
      final String ldapPasswd = 
        System.getProperty(Context.SECURITY_CREDENTIALS); 
      debug(Context.PROVIDER_URL + "=" + ldapServerUrl); 
      debug(Context.SECURITY_PRINCIPAL + "=" + ldapUser); 
      if (debug) { 
                  System.out.print(Context.SECURITY_CREDENTIALS + "="); 
                  final int len = (ldapPasswd==null)?0:ldapPasswd.length(); 
                  for (int i=0;i<len;i++) System.out.print("*"); 
                  System.out.println(); 
      } 
      env.put(Context.INITIAL_CONTEXT_FACTORY,factory); 
      env.put(Context.SECURITY_PRINCIPAL, ldapUser); 
      if (ldapServerUrl != null) 
           env.put(Context.PROVIDER_URL, ldapServerUrl); 
      if (ldapPasswd != null) 
           env.put(Context.SECURITY_CREDENTIALS, ldapPasswd); 
      InitialContext root = new InitialLdapContext(env,null); 
      return (DirContext)(root.lookup("")); 
  } 
   
[...] 
 

[...] 
 
public static void register(DirContext root, 
                           JMXServiceURL jmxUrl, 
                           String name) 
   throws NamingException, IOException { 
 
   final String mydn = System.getProperty("dn","cn="+name); 
 
   debug("dn: " + mydn ); 
 
   Object o = null; 
   try { 
       o = root.lookup(mydn); 
   } catch (NameNotFoundException n) { 
       Attributes attrs = new BasicAttributes(); 
       Attribute objclass = new BasicAttribute("objectClass"); 
       objclass.add("top"); 
       objclass.add("javaContainer"); 
       objclass.add("jmxConnector"); 
       attrs.put(objclass); 
       attrs.put("jmxAgentName", name); 
       o = root.createSubcontext(mydn,attrs); 
   } 
   if (o == null) throw new NameNotFoundException(); 
   final Attributes attrs = root.getAttributes(mydn); 
   final Attribute oc = attrs.get("objectClass"); 
   if (!oc.contains("jmxConnector")) { 
       final String msg = "The supplied node [" + mydn +  
         "] does not contain the jmxConnector objectclass"; 
       throw new NamingException(msg); 
   } 
    
   final Attributes newattrs = new BasicAttributes(); 
   newattrs.put("jmxAgentName",name); 
   newattrs.put("jmxServiceURL",jmxUrl.toString()); 
   newattrs.put("jmxAgentHost",InetAddress.getLocalHost().getHostName()); 
   newattrs.put("jmxProtocolType",jmxUrl.getProtocol()); 
   newattrs.put("jmxExpirationDate", 
                getExpirationDate(JMX_DEFAULT_LEASE)); 
   root.modifyAttributes(mydn,DirContext.REPLACE_ATTRIBUTE,newattrs); 
} 
 
[...] 
 

 
[...] 
 
   public JMXConnectorServer rmi(String url) 
     throws IOException, JMException, 
        NamingException, ClassNotFoundException { 
 
     JMXServiceURL jurl = new JMXServiceURL(url); 
     final HashMap env = new HashMap(); 
     // Prepare the environment Map 
     
[...] 
 
     JMXConnectorServer rmis = 
        JMXConnectorServerFactory.newJMXConnectorServer(jurl, env, mbs); 
 
     final String agentName = System.getProperty("agent.name", 
                                                 "DefaultAgent"); 
     start(rmis,env,agentName); 
     return rmis; 
   } 
     
[...] 
 

 
[...] 
 
    public void start(JMXConnectorServer server, Map env, String agentName) 
       throws IOException, NamingException { 
       server.start(); 
       final DirContext root=getRootContext(); 
       final JMXServiceURL address = server.getAddress(); 
       register(root,address,agentName); 
    } 
     
[...] 
 

 
[...] 
 
public class Client { 
 
   private static boolean debug = false; 
 
   public static void listAttributes(DirContext root, String dn) 
     throws NamingException { 
     final Attributes attrs = root.getAttributes(dn); 
     System.out.println("dn: " + dn); 
     System.out.println("attributes: " + attrs); 
   } 
    
   public static DirContext getRootContext() throws NamingException { 
      final Hashtable env = new Hashtable(); 
      // Prepare environment map 
      [...] 
       
      InitialContext root = new InitialLdapContext(env,null); 
      return (DirContext)(root.lookup("")); 
   } 
    
   // Confirm URL has not expired  
  [...]  
 
   public static List lookup(DirContext root, String protocolType, 
                             String name) 
      throws IOException, NamingException { 
      final ArrayList list = new ArrayList(); 
      String queryProtocol = 
         (protocolType==null)?"":"(jmxProtocolType="+protocolType+")"; 
      String query = 
          "(&" + "(objectClass=jmxConnector) " + 
          "(jmxServiceURL=*) " + 
          queryProtocol + 
          "(jmxAgentName=" + ((name!=null)?name:"*") + "))"; 
 
      SearchControls ctrls = new SearchControls(); 
      ctrls.setSearchScope(SearchControls.SUBTREE_SCOPE); 
      final NamingEnumeration results = root.search("", query, ctrls); 
      while (results.hasMore()) {  
           final SearchResult r = (SearchResult) results.nextElement(); 
           debug("Found node: " + r.getName()); 
           final Attributes attrs = r.getAttributes(); 
           final Attribute attr = attrs.get("jmxServiceURL"); 
           if (attr == null) continue; 
           final Attribute exp = attrs.get("jmxExpirationDate"); 
           if ((exp != null) && hasExpired((String)exp.get())) { 
               System.out.print(r.getName() + ": "); 
               System.out.println("URL expired since: " + exp.get()); 
               continue; 
           }   
           final String urlStr = (String)attr.get(); 
           if (urlStr.length() == 0) continue; 
 
    
           debug("Found URL: "+ urlStr); 
 
    
           final JMXServiceURL url = new JMXServiceURL(urlStr); 
           final JMXConnector conn = 
               JMXConnectorFactory.newJMXConnector(url,null); 
           list.add(conn); 
           if (debug) listAttributes(root,r.getName()); 
      } 
 
      return list; 
 
   }   
}