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 2005119@gmail.com
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<2005119@gmail.com> //@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<2005119@gmail.com> // @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<2005119@gmail.com> //@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 "                            "-e shutdown server"                            "/n",                            argv [0]),                           -1);       }   // Indicates sucessful parsing of the command line   return 0; } 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       FILE *output_file= ACE_OS::fopen (ior_output_file, "w");       if (output_file == 0)         ACE_ERROR_RETURN ((LM_ERROR,                            "Cannot open output file for writing IOR: %s/n",                            ior_output_file),                            1);       ACE_OS::fprintf (output_file, "%s", ior.in ());       ACE_OS::fclose (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<2005119@gmail.com> // @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<2005119@gmail.com> //@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<2005119@gmail.com> // @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 "                            "/n",                            argv [0]),                           -1);       }   // Indicates sucessful parsing of the command line   return 0; } 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 <%s>/n",                              ior),                             1);         }       CORBA::String_var the_string = hello->get_string ();       ACE_DEBUG ((LM_DEBUG, "(%P|%t) - string returned <%C>/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 2005119@gmail.com或在bbs (http://www.ace-tao.org/bbs)上留言。
http://www.ace-tao.org/home/link.php?url=d3d3LmFjZS10YW8ub3JnL2Jicw%3D%3D