跟我从头学TAO编程系列 (2) -- 编写最简单的TAO应用程序

跟我从头学TAO编程系列

编写最简单的TAO应用程序

Stone Jiang [email protected]

http://www.ace-tao.org

http://www.ace-tao.org/home/link.php?url=d3d3LmFjZS10YW8ub3JnL2Jicw%3D%3D

如果您对TAO有一定了解，却不知如何驾驭它，那请跟我来从头学学TAO编译。

如果您对TAO还不是非常了解的话，请跟我来，一起对TAO有一个初步的认识。

上一篇我们学会了如何下载、编译和安装TAO，这一节我们来编写最简单的TAO应用程序--Hello TAO!

1. 编写TAO应用程序的一般步骤

1)	定义接口，编写idl文件
2)	编写mpc文件，生成工程文件
3)	编写server端代码
4)	编写client端代码
5)	编译,调试运行，查看结果

2.定义接口

接口(interface)在TAO(corba)编程在非重要，它定义了客户端（主动发起请求一方）向服务端（被动等待请求）之间通讯消息格式。在本例在， 我们定义了一个名为"Hello"的接口。Hello接口中具有两个方法：

get_string() 和

shutdown()

TAO用接口定义语言(idl)来表示具体的接口定义。见Hello.idl文件

//@file: Test.idl //@author: StoneJiang //@ref : http://www.ace-tao.org /// Put the interfaces in a module, to avoid global namespace pollution module Test { /// A very simple interface interface Hello { /// Return a simple string string get_string (); /// A method to shutdown the ORB /** * This method is used to simplify the test shutdown process */ oneway void shutdown (); }; };

我们将接口Hello放在 module Test中，避免全局名字污染。

3.编写mpc文件

在上一篇我们简单的讲解了mpc在编译和ACE,TAO中的应用，在本节我们进一步使用mpc工具，为我们生成项目工程文件。

见Hello.mpc

//@file: Hello.mpc //@author: StoneJiang // @ref : http://www.ace-tao.org project(*idl): taoidldefaults { idlflags += -Sp IDL_Files { Test.idl } custom_only = 1 } project(*Server): taoserver { after += *idl Source_Files { Hello.cpp server.cpp } Source_Files { TestC.cpp TestS.cpp } IDL_Files { } } project(*Client): taoclient { after += *idl Source_Files { client.cpp } Source_Files { TestC.cpp } IDL_Files { } }

Hello.mpc定义了三个项目(project),其中*作为占位符，替换文件名Hello，所以这三个项目分别为

1) Hello_idl

2) Hello_Server

3) Hello_Client

4. 服务端代码的编写

服务端由 Server.cpp, Hello.cpp, Hello.h组成

// $Id: server.cpp 82798 2008-09-21 10:07:12Z johnnyw $ //@file: server.cpp //@author: StoneJiang //@ref : http://www.ace-tao.org #include "Hello.h" #include "ace/Get_Opt.h" #include "ace/OS_NS_stdio.h" const ACE_TCHAR *ior_output_file = ACE_TEXT ("test.ior"); int parse_args (int argc, ACE_TCHAR *argv[]) { ACE_Get_Opt get_opts (argc, argv, ACE_TEXT("o:")); int c; while ((c = get_opts ()) != -1) switch (c) { case 'o': ior_output_file = get_opts.opt_arg (); break; case '?': default: ACE_ERROR_RETURN ((LM_ERROR, "usage: %s " "-o <iorfile> " <br> "-e shutdown server" <br> "\n", <br> argv [0]), <br> -1); <br> } <br> // Indicates sucessful parsing of the command line <br> return 0; <br>} </iorfile> int ACE_TMAIN(int argc, ACE_TCHAR *argv[]) { try { CORBA::ORB_var orb = CORBA::ORB_init (argc, argv); CORBA::Object_var poa_object = orb->resolve_initial_references("RootPOA"); PortableServer::POA_var root_poa = PortableServer::POA::_narrow (poa_object.in ()); if (CORBA::is_nil (root_poa.in ())) ACE_ERROR_RETURN ((LM_ERROR, " (%P|%t) Panic: nil RootPOA\n"), 1); PortableServer::POAManager_var poa_manager = root_poa->the_POAManager (); if (parse_args (argc, argv) != 0) return 1; poa_manager->activate (); Hello *hello_impl = 0; ACE_NEW_RETURN (hello_impl, Hello (orb.in ()), 1); PortableServer::ServantBase_var owner_transfer(hello_impl); PortableServer::ObjectId_var id = root_poa->activate_object (hello_impl); CORBA::Object_var object = root_poa->id_to_reference (id.in ()); Test::Hello_var hello = Test::Hello::_narrow (object.in ()); CORBA::String_var ior = orb->object_to_string (hello.in ()); // Output the IOR to the <ior_output_file><br> FILE *output_file= ACE_OS::fopen (ior_output_file, "w"); <br> if (output_file == 0) <br> ACE_ERROR_RETURN ((LM_ERROR, <br> "Cannot open output file for writing IOR: %s\n", <br> ior_output_file), <br> 1); <br> ACE_OS::fprintf (output_file, "%s", ior.in ()); <br> ACE_OS::fclose (output_file); </ior_output_file> ACE_DEBUG ((LM_DEBUG, "(%P|%t) server - wait for requsting from client.\n")); orb->run (); ACE_DEBUG ((LM_DEBUG, "(%P|%t) server - event loop finished\n")); root_poa->destroy (1, 1); orb->destroy (); } catch (const CORBA::Exception& ex) { ex._tao_print_exception ("Exception caught:"); return 1; } return 0; }

//@file: Hello.cpp //@author: StoneJiang // @ref : http://www.ace-tao.org #include "Hello.h" #include "ace/Log_Msg.h" Hello::Hello (CORBA::ORB_ptr orb) : orb_ (CORBA::ORB::_duplicate (orb)) { } char * Hello::get_string (void) { ACE_DEBUG ((LM_DEBUG, "(%P|%t) server - get_string().\n")); return CORBA::string_dup ("Hello TAO!"); } void Hello::shutdown (void) { ACE_DEBUG ((LM_DEBUG, "(%P|%t) server - shutdown().\n")); this->orb_->shutdown (0); }

//@file: Hello.h //@author: StoneJiang //@ref : http://www.ace-tao.org #ifndef HELLO_H #define HELLO_H #include /**/ "ace/pre.h" #include "TestS.h" /// Implement the Test::Hello interface class Hello : public virtual POA_Test::Hello { public: /// Constructor Hello (CORBA::ORB_ptr orb); // = The skeleton methods virtual char * get_string (void); virtual void shutdown (void); private: /// Use an ORB reference to convert strings to objects and shutdown /// the application. CORBA::ORB_var orb_; }; #include /**/ "ace/post.h" #endif /* HELLO_H */

5. 客户端代码的编写

服务端由 client.cpp组件

// @file: client.cpp StoneJiang // @ref : http://www.ace-tao.org #include "TestC.h" #include "ace/Get_Opt.h" const ACE_TCHAR *ior = ACE_TEXT ("file://test.ior"); int end = 0; int parse_args (int argc, ACE_TCHAR *argv[]) { ACE_Get_Opt get_opts (argc, argv, ACE_TEXT("k: e")); int c; while ((c = get_opts ()) != -1) switch (c) { case 'k': ior = get_opts.opt_arg (); break; case 'e': end = 1; break; case '?': default: ACE_ERROR_RETURN ((LM_ERROR, "usage: %s " "-k <ior> " <br> "\n", <br> argv [0]), <br> -1); <br> } <br> // Indicates sucessful parsing of the command line <br> return 0; <br>} </ior> int ACE_TMAIN(int argc, ACE_TCHAR *argv[]) { try { CORBA::ORB_var orb = CORBA::ORB_init (argc, argv); if (parse_args (argc, argv) != 0) return 1; CORBA::Object_var tmp = orb->string_to_object(ior); Test::Hello_var hello = Test::Hello::_narrow(tmp.in ()); if (CORBA::is_nil (hello.in ())) { ACE_ERROR_RETURN ((LM_DEBUG, "Nil Test::Hello reference \n", ior), 1); } CORBA::String_var the_string = hello->get_string (); ACE_DEBUG ((LM_DEBUG, "(%P|%t) - string returned \n", the_string.in ())); if (end) { hello->shutdown (); } orb->destroy (); } catch (const CORBA::Exception& ex) { ex._tao_print_exception ("Exception caught:"); return 1; } return 0; }

6. 编译、调试和运行

6.1 生成工程文件

在Dos Shell中输入

mwc.pl -type vc9

如下图:

6.2 打开工程文件

用Visual Studio 2008打开工程文档

编译后得到 server.exe和client.exe

6.3 运行服务端

6.4 运行客户端

6.5 运行客户端，并让服务端退出

7. 结束

到此，我们最简单的已经运行成功。

完整的源代码将上传到http://www.ace-tao.org/home/link.php?url=d3d3LmFjZS10YW8ub3JnL2Jicw%3D%3D

源代码中已为你生成了vc9,vc8,vc71以及linux GNUmakefile文件。

我们将接下来对本例在的代码作解释,敬请关注。

有任何问题，请来邮件 [email protected]或在bbs (http://www.ace-tao.org/bbs)上留言。

http://www.ace-tao.org/home/link.php?url=d3d3LmFjZS10YW8ub3JnL2Jicw%3D%3D