<refmiscinfo class="copyright"> Copyright 2001 Sun Microsystems, Inc. All rights reserved. Copyright 2001 Sun Microsystems, Inc. Tous droits réservés. </refmiscinfo>
</refmeta>
<refnamediv><refname>tnameserv</refname><refpurpose>Java IDL name server starter script</refpurpose></refnamediv>
<indexterm id="tnameserv-1-indx-1"><primary sortas="Java IDL name server starter script">Java IDL name server starter script — tnameserv</primary></indexterm><indexterm id="tnameserv-1-indx-2"><primary sortas="tnameserv">tnameserv — Java IDL name server starter script</primary></indexterm><para>The <acronym>CORBA</acronym> <acronym>COS</acronym> (Common Object Services) Naming Service provides
a tree-like directory for object references much like a filesystem provides a directory structure for files. The Naming Service provided with Java <acronym remap="small">IDL</acronym> is a simple implementation of the <acronym remap="small">COS</acronym> Naming Service specification.</para>
<para>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
binding in the namespace; the rest of the namespace is lost if the Java <acronym>IDL</acronym> name server process halts and restarts.</para>
<para>For an applet or application to use <acronym>COS</acronym> naming, its <acronym>ORB</acronym> 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 <acronym>IDL</acronym> name server or another <acronym>COS</acronym>-compliant name service.</para>
</refsect1>
<refsect1><title>&usge-tt;</title>
<refsect2><title>Starting the Java IDL Name Server</title>
<indexterm id="tnameserv-1-indx-3"><primary sortas="tnameserv">tnameserv — Java IDL name server starter script</primary><secondary>Starting the Java IDL Name Server</secondary></indexterm><para>You must start the Java <acronym>IDL</acronym> name server before an application or applet that uses its naming service. Installation of the Java <acronym>IDL</acronym> product creates a script named <literal>
tnameserv</literal> that starts the Java <acronym>IDL</acronym> name server. Start the name server so it runs in the background.</para>
<para>If you do not specify otherwise, the Java <acronym>IDL</acronym> name server listens on port 900 for the bootstrap protocol used to implement the <acronym>ORB</acronym> <function>resolve_initial_references</function> and <function>list_initial_references</function> methods. Specify a different port, for example <literal>1050</literal>, as follows:<informalexample><para><screen>example% <userinput>
<para>Clients of the name server must be made aware of the new port number. Do this by setting the <literal>org.omg.CORBA.ORBInitialPort</literal> property to the new port number when creating the <acronym>ORB</acronym> object.</para>
</refsect2>
<refsect2><title>Stopping the Java IDL Name Server</title>
<indexterm id="tnameserv-1-indx-4"><primary sortas="tnameserv">tnameserv — Java IDL name server starter script</primary><secondary>Stopping the Java IDL Name Server</secondary></indexterm><para>To stop the Java <acronym remap="small">IDL</acronym> name server, use the relevant operating system command, such as <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
Notice that names registered with the Java <acronym remap="small">IDL</acronym> name service disappear when the server is terminated.</para>
<indexterm id="tnameserv-1-indx-5"><primary sortas="tnameserv">tnameserv — Java IDL name server starter script</primary><secondary>Sample Client: Browsing the Namespace</secondary></indexterm><indexterm id="tnameserv-1-indx-6"><primary sortas="tnameserv">tnameserv — Java IDL name server starter script</primary><secondary>Sample Client: Adding Objects to the Namespace</secondary></indexterm>
<para>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.<informalexample><screen> Initial
Naming Context
/ \
/ \
plans personal
/\
/ \
calendar schedule
</screen>
</informalexample>In this example, <literal>plans</literal> is an object reference and <literal>personal</literal> is a naming context that contains two object references, <literal>calendar</literal> and <literal>schedule</literal>.<informalexample><screen>import java.util.Properties;
import org.omg.CORBA.*;
import org.omg.CosNaming.*;
public class NameClient
{
public static void main(String args[])
{
try {
</screen>
</informalexample>In the above section, <literal>Starting the Java IDL Name Server</literal>, the nameserver was started on port <literal>1050</literal>. The following code ensures that the client program is aware of this port number.<informalexample><screen> Properties props = new Properties();
</informalexample>The following code obtains the initial naming context and assigns it to <literal>ctx</literal>. The second line copies <literal>ctx</literal> into a dummy object reference, <literal>objref</literal>, that we will attach to various names and add into the namespace.<informalexample><screen> NamingContext ctx = NamingContextHelper.narrow
(orb.resolve_initial_references("NameService"));
NamingContext objref = ctx;
</screen>
</informalexample>The following code creates a name <literal>plans</literal> of type <literal>text</literal> and binds it to our dummy object reference. <literal>plans</literal> is then added under the initial naming context using <literal>rebind</literal>. The <literal>rebind</literal> method allows us to run this program over and over again without getting the exceptions we would get from using <literal>
bind</literal>.<informalexample><screen> NameComponent nc1 = new NameComponent("plans", "text");
NameComponent[] name1 = {nc1};
ctx.rebind(name1, objref);
System.out.println("plans rebind sucessful!");
</screen>
</informalexample>The following code creates a naming context called <literal>Personal</literal> of type <literal>directory</literal>. The resulting object reference, <literal>ctx2</literal>, is bound to the name and added under the initial naming context.<informalexample><screen> NameComponent nc2 = new NameComponent("Personal", "directory");
NameComponent[] name2 = {nc2};
NamingContext ctx2 = ctx.bind_new_context(name2);
System.out.println("new naming context added..");
</screen>
</informalexample>The remainder of the code binds the dummy object reference using the names <literal>schedule</literal> and <literal>calendar</literal> under the <literal>Personal</literal> naming context (<literal>ctx2</literal>).<informalexample><screen> 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);
}
}
}
</screen>
</informalexample></para>
</refsect2>
<refsect2><title>Sample Client: Browsing the Namespace</title>
<para>The following sample program illustrates how to browse the namespace.<informalexample><?Pub Caret><screen>import java.util.Properties;
import org.omg.CORBA.*;
import org.omg.CosNaming.*;
public class NameClientList
{
public static void main(String args[])
{
try {
</screen>
</informalexample>In the above section, <literal>Starting the Java IDL Name Server</literal>, the nameserver was started on port <literal>1050</literal>. The following code ensures that the client program is aware of this port number.<informalexample><screen> Properties props = new Properties();
</informalexample>The following code obtains the initial naming context.<informalexample><screen> NamingContext nc = NamingContextHelper.narrow
(orb.resolve_initial_references("NameService"));
</screen>
</informalexample>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 <literal>BindingListHolder</literal>. Any remaining bindings are returned in the <literal>BindingIteratorHolder</literal>.<informalexample><screen> BindingListHolder bl = new BindingListHolder();
BindingIteratorHolder blIt= new BindingIteratorHolder();
nc.list(1000, bl, blIt);
</screen>
</informalexample>The following code gets the array of bindings out of the returned <literal>BindingListHolder</literal>. If there are no bindings, the program ends.<informalexample><screen> Binding bindings[] = bl.value;
if (bindings.length == 0) return;
</screen>
</informalexample>The remainder of the code loops through the bindings and prints the names out. <screen> 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) {
<para>See <olink targetdocent="REFMAN5" localinfo="attributes-5"><citerefentry><refentrytitle>attributes</refentrytitle><manvolnum>5</manvolnum></citerefentry></olink> for a description of the following attributes:</para>
