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tnameserv(1)                                                                                    tnameserv(1)



NAME
       tnameserv - Java IDL name server starter script

SYNOPSIS
       tnameserv -ORBInitialPort portNumber

DESCRIPTION
       The  CORBA COS (Common Object Services) Naming Service provides a tree-like directory for object ref-erences references
       erences much like a filesystem provides a directory structure for files.  The Naming Service provided
       with Java IDL is a simple implementation of the COS Naming Service specification.

       Object references are stored in the namespace by name and each object reference-name pair is called a
       name binding.  Name bindings may be organized under naming contexts.  Naming contexts are  themselves
       name bindings and serve the same organizational function as a file system subdirectory.  All bindings
       are stored under the initial naming context.  The initial naming context is the only persistent bind-ing binding
       ing in the namespace; the rest of the namespace is lost if the Java IDL name server process halts and
       restarts.

       For an applet or application to use COS naming, its ORB must know the name and port of a host running
       a  naming  service  or have access to a stringified initial naming context for that name server.  The
       naming service can either be the Java IDL name server or another COS-compliant name service.

USAGE
   Starting the Java IDL Name Server
       You must start the Java IDL name server before an application or applet that uses its naming service.
       Installation  of  the Java IDL product creates a script named tnameserv that starts the Java IDL name
       server.  Start the name server so it runs in the background.

       If you do not specify otherwise, the Java IDL name server listens on port 900 for the bootstrap  pro-tocol protocol
       tocol  used  to implement the ORB resolve_initial_references() and list_initial_references() methods.
       Specify a different port, for example, 1050, as follows:

              example% tnameserv -ORBInitialPort 1050

       Clients of the name server must be made aware of the  new  port  number.   Do  this  by  setting  the
       org.omg.CORBA.ORBInitialPort property to the new port number when creating the ORB object.

   Stopping the Java IDL Name Server
       To  stop  the Java IDL name server, use the relevant operating system command, such as kill(1).  Note
       that names registered with the Java IDL name service disappear when the server is terminated.

   Sample Client: Adding Objects
       The following sample program illustrates how to add names to the namespace.  It is  a  self-contained
       Name Server client that creates the following simple tree.

               Initial
            Naming Context
              /      \
             /        \
          plans      personal
                       /\
                      /  \
               calendar   schedule

       In  this example, "plans" is an object reference and "personal" is a naming context that contains two
       object references: "calendar" and "schedule".

       import java.util.Properties;
       import org.omg.CORBA.*;
       import org.omg.CosNaming.*;

       public class NameClient
       {
          public static void main(String args[])
          {
             try {

       In the above section, Starting the Java IDL Name Server, the nameserver was  started  on  port  1050.
       The following code ensures that the client program is aware of this port number.

               Properties props = new Properties();
               props.put("org.omg.CORBA.ORBInitialPort", "1050");
               ORB orb = ORB.init(args, props);

       The  following code obtains the initial naming context and assigns it to ctx.  The second line copies
       ctx into a dummy object reference, objref, that we will attach to various  names  and  add  into  the
       namespace.

               NamingContext ctx = NamingContextHelper.narrow
                   (orb.resolve_initial_references("NameService"));
               NamingContext objref = ctx;

       The  following code creates a name "plans" of type "text" and binds it to our dummy object reference.
       "plans" is then added under the initial naming context using rebind.  The rebind method allows us  to
       run this program over and over again without getting the exceptions we would get from using bind.

               NameComponent nc1 = new NameComponent("plans", "text");
               NameComponent[] name1 = {nc1};
               ctx.rebind(name1, objref);
               System.out.println("plans rebind sucessful!");

       The  following  code  creates  a naming context called "Personal" of type "directory".  The resulting
       object reference, ctx2, is bound to the name and added under the initial naming context.

               NameComponent nc2 = new NameComponent("Personal", "directory");
               NameComponent[] name2 = {nc2};
               NamingContext ctx2 = ctx.bind_new_context(name2);
               System.out.println("new naming context added..");

       The remainder of the code binds the dummy object reference using the names "schedule" and  "calendar"
       under the "Personal" naming context (ctx2).

               NameComponent nc3 = new NameComponent("schedule", "text");
               NameComponent[] name3 = {nc3};
               ctx2.rebind(name3, objref);
               System.out.println("schedule rebind sucessful!");

               NameComponent nc4 = new NameComponent("calender", "text");
               NameComponent[] name4 = {nc4};
               ctx2.rebind(name4, objref);
               System.out.println("calender rebind sucessful!");

           } catch (Exception e) {
               e.printStackTrace(System.err);
           }
         }
       }


   Sample Client: Browsing the Namespace
       The following sample program illustrates how to browse the namespace.

       import java.util.Properties;
       import org.omg.CORBA.*;
       import org.omg.CosNaming.*;

       public class NameClientList
       {
          public static void main(String args[])
          {
             try {

       In  the  above  section,  Starting the Java IDL Name Server, the nameserver was started on port 1050.
       The following code ensures that the client program is aware of this port number.

               Properties props = new Properties();
               props.put("org.omg.CORBA.ORBInitialPort", "1050");
               ORB orb = ORB.init(args, props);

       The following code obtains the initial naming context.

               NamingContext nc = NamingContextHelper.narrow
                  (orb.resolve_initial_references("NameService"));

       The list method lists the bindings in the naming context.  In this case, up to 1000 bindings from the
       initial naming context will be returned in the BindingListHolder; any remaining bindings are returned
       in the BindingIteratorHolder.

               BindingListHolder bl = new BindingListHolder();
               BindingIteratorHolder blIt= new BindingIteratorHolder();
               nc.list(1000, bl, blIt);

       The following code gets the array of bindings out of the returned BindingListHolder.  If there are no
       bindings, the program ends.

               Binding bindings[] = bl.value;
               if (bindings.length == 0) return;

       The remainder of the code loops through the bindings and prints the names out.

               for (int i=0; i < bindings.length; i++) {

                   // get the object reference for each binding
                   org.omg.CORBA.Object obj = nc.resolve
                            (bindings[i].binding_name);
                   String objStr = orb.object_to_string(obj);
                   int lastIx = bindings[i].binding_name.length-1;

                   // check to see if this is a naming context
                   if (bindings[i].binding_type == BindingType.ncontext) {
                     System.out.println
                            ("Context: " + bindings[i].binding_name[lastIx].id);
                   } else {
                       System.out.println
                              ("Object: " + bindings[i].binding_name[lastIx].id);
                   }
               }

              } catch (Exception e) {
               e.printStackTrace(System.err);
              }
          }
       }


SEE ALSO
       kill(1)



                                                13 June 2000                                    tnameserv(1)