tnameserv.1 revision 5116:d45bc4307996
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Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19." or visit www.oracle.com if you need additional information or have any 20." questions. 21." 22.TH tnameserv 1 "10 May 2011" 23 24.LP 25.SH "Name" 26Java IDL: Transient Naming Service \- \f2tnameserv\fP 27.LP 28.LP 29This document discusses using the Java IDL Transient Naming Service, \f2tnameserv\fP. Java IDL also includes the Object Request Broker Daemon (ORBD). ORBD is a daemon process containing a Bootstrap Service, a Transient Naming Service, a \f3Persistent\fP Naming Service, and a Server Manager. The Java IDL tutorials all use ORBD, however, you can substitute \f2tnameserv\fP for \f2orbd\fP in any of the examples that use a Transient Naming Service. For documentation on the \f2orbd\fP tool, link to its orbd(1) or the 30.na 31\f2Java IDL Naming Service Included with ORBD\fP @ 32.fi 33http://download.oracle.com/javase/7/docs/technotes/guides/idl/jidlNaming.html topic. 34.LP 35.LP 36Topics in this section include: 37.LP 38.RS 3 39.TP 2 40o 41Java\ IDL Transient Naming Service 42.TP 2 43o 44Starting the Java\ IDL Transient Naming Service 45.TP 2 46o 47Stopping the Java\ IDL Transient Naming Service 48.TP 2 49o 50Sample Client: Adding Objects to the Namespace 51.TP 2 52o 53Sample Client: Browsing the Namespace 54.RE 55 56.LP 57.SH "Java\ IDL Transient Naming Service" 58.LP 59.LP 60The CORBA COS (Common Object Services) Naming Service provides a tree\-like directory for object references much like a filesystem provides a directory structure for files. The Transient Naming Service provided with Java IDL, \f2tnameserv\fP, is a simple implementation of the COS Naming Service specification. 61.LP 62.LP 63Object references are stored in the namespace by name and each object reference\-name pair is called a name \f2binding\fP. Name bindings may be organized under \f2naming contexts\fP. Naming contexts are themselves name bindings and serve the same organizational function as a file system subdirectory. All bindings are stored under the \f2initial naming context\fP. The initial naming context is the only persistent binding in the namespace; the rest of the namespace is lost if the Java IDL naming service process halts and restarts. 64.LP 65.LP 66For an applet or application to use COS naming, its ORB must know the port of a host running a naming service or have access to a stringified initial naming context for that naming service. The naming service can either be the Java\ IDL naming service or another COS\-compliant naming service. 67.LP 68.SH "Starting the Java\ IDL Transient Naming Service" 69.LP 70.LP 71You must start the Java\ IDL naming service before an application or applet that uses its naming service. Installation of the Java\ IDL product creates a script (Solaris: \f2tnameserv\fP) or executable file (Windows NT: \f2tnameserv.exe\fP) that starts the Java\ IDL naming service. Start the naming service so it runs in the background. 72.LP 73.LP 74If you do not specify otherwise, the Java\ IDL naming service listens on port 900 for the bootstrap protocol used to implement the ORB \f2resolve_initial_references()\fP and \f2list_initial_references()\fP methods, as follows: 75.LP 76.nf 77\f3 78.fl 79 tnameserv \-ORBInitialPort \fP\f4nameserverport\fP\f3& 80.fl 81\fP 82.fi 83 84.LP 85.LP 86If you do not specify the name server port, port 900 is used by default. When running Solaris software, you must become root to start a process on a port under 1024. For this reason, we recommend that you use a port number greater than or equal to 1024. To specify a different port, for example, 1050, and to run the naming service in the background, from a UNIX command shell, enter: 87.LP 88.nf 89\f3 90.fl 91 tnameserv \-ORBInitialPort 1050& 92.fl 93\fP 94.fi 95 96.LP 97.LP 98From an MS\-DOS system prompt (Windows), enter: 99.LP 100.nf 101\f3 102.fl 103 start tnameserv \-ORBInitialPort 1050 104.fl 105\fP 106.fi 107 108.LP 109.LP 110Clients of the name server must be made aware of the new port number. Do this by setting the \f2org.omg.CORBA.ORBInitialPort\fP property to the new port number when creating the ORB object. 111.LP 112.SS 113Running the server and client on different hosts 114.LP 115.LP 116In most of the Java IDL and RMI\-IIOP tutorials, the Naming Service, Server, and Client are all running on the development machine. In real world deployment, it is likely that the client and server will run on different host machines than the Naming Service. 117.LP 118.LP 119For the client and server to find the Naming Service, they must be made aware of the port number and host on which the naming service is running. Do this by setting the \f2org.omg.CORBA.ORBInitialPort\fP and \f2org.omg.CORBA.ORBInitialHost\fP properties in the client and server files to the machine name and port number on which the Naming Service is running. An example of this is shown in 120.na 121\f2The Hello World Example Using RMI\-IIOP\fP @ 122.fi 123http://download.oracle.com/javase/7/docs/technotes/guides/rmi\-iiop/rmiiiopexample.html. You could also use the command line options \f2\-ORBInitialPort\fP \f2nameserverport#\fP and \f2\-ORBInitialHost\fP \f2nameserverhostname\fP to tell the client and server where to find the Naming Service. 124.na 125\f2Java IDL: Running the Hello World Example on TWO Machines\fP @ 126.fi 127http://download.oracle.com/javase/7/docs/technotes/guides/idl/tutorial/jidl2machines.html shows one way of doing this using the command line option. 128.LP 129.LP 130For example, suppose the Transient Naming Service, \f2tnameserv\fP is running on port 1050 on host \f2nameserverhost\fP. The client is running on host \f2clienthost\fP and the server is running on host \f2serverhost\fP. 131.LP 132.RS 3 133.TP 2 134o 135Start \f2tnameserv\fP on the host \f2nameserverhost\fP, as follows: 136.nf 137\f3 138.fl 139 tnameserv \-ORBInitialPort 1050 140.fl 141 142.fl 143\fP 144.fi 145.TP 2 146o 147Start the server on the \f2serverhost\fP, as follows: 148.nf 149\f3 150.fl 151 java Server \-ORBInitialPort 1050 \-ORBInitialHost nameserverhost 152.fl 153\fP 154.fi 155.TP 2 156o 157Start the client on the \f2clienthost\fP, as follows: 158.nf 159\f3 160.fl 161 java Client \-ORBInitialPort 1050 \-ORBInitialHost nameserverhost 162.fl 163\fP 164.fi 165.RE 166 167.LP 168.SS 169The \-J option 170.LP 171This command\-line option is available for use with \f2tnameserve\fP: 172.RS 3 173.TP 3 174\-Joption 175Pass \f2option\fP to the Java virtual machine, where \f2option\fP is one of the options described on the reference page for java(1). For example, \f3\-J\-Xms48m\fP sets the startup memory to 48 megabytes. It is a common convention for \f3\-J\fP to pass options to the underlying virtual machine. 176.RE 177 178.LP 179.SH "Stopping the Java\ IDL Transient Naming Service" 180.LP 181.LP 182To stop the Java\ IDL naming service, use the relevant operating system command, such as \f2kill\fP for a Unix process, or \f2Ctrl\-C\fP for a Windows process. The naming service will continue to wait for invocations until it is explicitly shutdown. Note that names registered with the Java\ IDL naming service disappear when the service is terminated. 183.LP 184.SH "Sample Client: Adding Objects to the Namespace" 185.LP 186.LP 187The following sample program illustrates how to add names to the namespace. It is a self\-contained Transient Naming Service client that creates the following simple tree. 188.LP 189.RS 3 190.TP 2 191o 192\f4Initial Naming Context\fP 193.RS 3 194.TP 2 195* 196\f3plans\fP 197.TP 2 198* 199\f4Personal\fP 200.RS 3 201.TP 2 202- 203\f3calendar\fP 204.TP 2 205- 206\f3schedule\fP 207.RE 208.RE 209.RE 210 211.LP 212.LP 213In this example, \f3plans\fP is an object reference and \f3Personal\fP is a naming context that contains two object references: \f3calendar\fP and \f3schedule\fP. 214.LP 215.nf 216\f3 217.fl 218import java.util.Properties; 219.fl 220import org.omg.CORBA.*; 221.fl 222import org.omg.CosNaming.*; 223.fl 224 225.fl 226public class NameClient 227.fl 228{ 229.fl 230 public static void main(String args[]) 231.fl 232 { 233.fl 234 try { 235.fl 236\fP 237.fi 238 239.LP 240In the above section, Starting the Java IDL Transient Naming Service, the nameserver was started on port 1050. The following code ensures that the client program is aware of this port number. 241.nf 242\f3 243.fl 244 Properties props = new Properties(); 245.fl 246 props.put("org.omg.CORBA.ORBInitialPort", "1050"); 247.fl 248 ORB orb = ORB.init(args, props); 249.fl 250 251.fl 252\fP 253.fi 254 255.LP 256This code obtains the initial naming context and assigns it to \f3ctx\fP. The second line copies \f3ctx\fP into a dummy object reference \f3objref\fP that we'll attach to various names and add into the namespace. 257.nf 258\f3 259.fl 260 NamingContext ctx = 261.fl 262NamingContextHelper.narrow(orb.resolve_initial_references("NameService")); 263.fl 264 NamingContext objref = ctx; 265.fl 266 267.fl 268\fP 269.fi 270 271.LP 272This 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 \f2rebind\fP. The \f2rebind\fP method allows us to run this program over and over again without getting the exceptions we'd get from using \f2bind\fP. 273.nf 274\f3 275.fl 276 NameComponent nc1 = new NameComponent("plans", "text"); 277.fl 278 NameComponent[] name1 = {nc1}; 279.fl 280 ctx.rebind(name1, objref); 281.fl 282 System.out.println("plans rebind sucessful!"); 283.fl 284 285.fl 286\fP 287.fi 288 289.LP 290This code creates a naming context called "Personal" of type "directory". The resulting object reference, \f3ctx2\fP, is bound to the name and added under the initial naming context. 291.nf 292\f3 293.fl 294 NameComponent nc2 = new NameComponent("Personal", "directory"); 295.fl 296 NameComponent[] name2 = {nc2}; 297.fl 298 NamingContext ctx2 = ctx.bind_new_context(name2); 299.fl 300 System.out.println("new naming context added.."); 301.fl 302 303.fl 304\fP 305.fi 306 307.LP 308The remainder of the code binds the dummy object reference using the names "schedule" and "calendar" under the "Personal" naming context (\f3ctx2\fP). 309.nf 310\f3 311.fl 312 NameComponent nc3 = new NameComponent("schedule", "text"); 313.fl 314 NameComponent[] name3 = {nc3}; 315.fl 316 ctx2.rebind(name3, objref); 317.fl 318 System.out.println("schedule rebind sucessful!"); 319.fl 320 321.fl 322 NameComponent nc4 = new NameComponent("calender", "text"); 323.fl 324 NameComponent[] name4 = {nc4}; 325.fl 326 ctx2.rebind(name4, objref); 327.fl 328 System.out.println("calender rebind sucessful!"); 329.fl 330 331.fl 332 333.fl 334 } catch (Exception e) { 335.fl 336 e.printStackTrace(System.err); 337.fl 338 } 339.fl 340 } 341.fl 342} 343.fl 344\fP 345.fi 346 347.LP 348.SH "Sample Client: Browsing the Namespace" 349.LP 350.LP 351The following sample program illustrates how to browse the namespace. 352.LP 353.nf 354\f3 355.fl 356import java.util.Properties; 357.fl 358import org.omg.CORBA.*; 359.fl 360import org.omg.CosNaming.*; 361.fl 362 363.fl 364public class NameClientList 365.fl 366{ 367.fl 368 public static void main(String args[]) 369.fl 370 { 371.fl 372 try { 373.fl 374\fP 375.fi 376 377.LP 378In the above section, Starting the Java IDL Transient Naming Service, the nameserver was started on port 1050. The following code ensures that the client program is aware of this port number. 379.nf 380\f3 381.fl 382 383.fl 384 Properties props = new Properties(); 385.fl 386 props.put("org.omg.CORBA.ORBInitialPort", "1050"); 387.fl 388 ORB orb = ORB.init(args, props); 389.fl 390 391.fl 392 393.fl 394\fP 395.fi 396 397.LP 398The following code obtains the intial naming context. 399.nf 400\f3 401.fl 402 NamingContext nc = 403.fl 404NamingContextHelper.narrow(orb.resolve_initial_references("NameService")); 405.fl 406 407.fl 408\fP 409.fi 410 411.LP 412The \f2list\fP 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. 413.nf 414\f3 415.fl 416 BindingListHolder bl = new BindingListHolder(); 417.fl 418 BindingIteratorHolder blIt= new BindingIteratorHolder(); 419.fl 420 nc.list(1000, bl, blIt); 421.fl 422 423.fl 424\fP 425.fi 426 427.LP 428This code gets the array of bindings out of the returned BindingListHolder. If there are no bindings, the program ends. 429.nf 430\f3 431.fl 432 Binding bindings[] = bl.value; 433.fl 434 if (bindings.length == 0) return; 435.fl 436 437.fl 438\fP 439.fi 440 441.LP 442The remainder of the code loops through the bindings and prints the names out. 443.nf 444\f3 445.fl 446 for (int i=0; i < bindings.length; i++) { 447.fl 448 449.fl 450 // get the object reference for each binding 451.fl 452 org.omg.CORBA.Object obj = nc.resolve(bindings[i].binding_name); 453.fl 454 String objStr = orb.object_to_string(obj); 455.fl 456 int lastIx = bindings[i].binding_name.length\-1; 457.fl 458 459.fl 460 // check to see if this is a naming context 461.fl 462 if (bindings[i].binding_type == BindingType.ncontext) { 463.fl 464 System.out.println( "Context: " + 465.fl 466bindings[i].binding_name[lastIx].id); 467.fl 468 } else { 469.fl 470 System.out.println("Object: " + 471.fl 472bindings[i].binding_name[lastIx].id); 473.fl 474 } 475.fl 476 } 477.fl 478 479.fl 480 } catch (Exception e) { 481.fl 482 e.printStackTrace(System.err); 483.fl 484 } 485.fl 486 } 487.fl 488} 489.fl 490\fP 491.fi 492 493.LP 494 495