客户端使用java，服务端使用c++的corba编程环境搭建

我们先用c++实现服务端和客户端，然后再用java编写客户端。

1. 首先安装omniORB，omniORB提供 omniidl命令，以及一些头文件和库。

omniORB一般是需要你自己进行编译。

2. 编写idl文件，本实验中文件名为 echo.idl

 interface Echo { string echoString(in string mesg); };

echo.idl

3. 使用omniidl -bcxx echo.idl 生成 echo.hh 和 echoSK.cc

4. 编写用c++实现的服务端和客户端，本实验中是 server.cpp client.cpp

 // eg3_impl.cc - This is the source code of example 3 used in Chapter 2
 //               "The Basics" of the omniORB user guide.
 //
 //               This is the object implementation.
 //
 // Usage: eg3_impl
 //
 //        On startup, the object reference is registered with the
 //        COS naming service. The client uses the naming service to
 //        locate this object.
 //
 //        The name which the object is bound to is as follows:
 //              root  [context]
 //               |
 //              test  [context] kind [my_context]
 //               |
 //              Echo  [object]  kind [Object]
 //

 #include "echo.hh"

 #ifdef HAVE_STD
 #  include <iostream>
    using namespace std;
 #else
 #  include <iostream.h>
 #endif

 static CORBA::Boolean bindObjectToName(CORBA::ORB_ptr, CORBA::Object_ptr);

 class Echo_i : public POA_Echo
 {
 public:
   inline Echo_i() {}
   virtual ~Echo_i() {}
   virtual char* echoString(const char* mesg);
 };

 char* Echo_i::echoString(const char* mesg)
 {
   return CORBA::string_dup(mesg);
 }

 //////////////////////////////////////////////////////////////////////

 int
 main(int argc, char **argv)
 {
   try {
     CORBA::ORB_var          orb = CORBA::ORB_init(argc, argv);
     CORBA::Object_var       obj = orb->resolve_initial_references("RootPOA");
     PortableServer::POA_var poa = PortableServer::POA::_narrow(obj);

     PortableServer::Servant_var<Echo_i> myecho = new Echo_i();

     PortableServer::ObjectId_var myechoid = poa->activate_object(myecho);

     // Obtain a reference to the object, and register it in
     // the naming service.
     obj = myecho->_this();

     CORBA::String_var sior(orb->object_to_string(obj));
     cout << sior << endl;

     if (!bindObjectToName(orb, obj))
       return ;

     PortableServer::POAManager_var pman = poa->the_POAManager();
     pman->activate();

     orb->run();
   }
   catch (CORBA::SystemException& ex) {
     cerr << "Caught CORBA::" << ex._name() << endl;
   }
   catch (CORBA::Exception& ex) {
     cerr << "Caught CORBA::Exception: " << ex._name() << endl;
   }
   return ;
 }

 //////////////////////////////////////////////////////////////////////

 static CORBA::Boolean
 bindObjectToName(CORBA::ORB_ptr orb, CORBA::Object_ptr objref)
 {
   CosNaming::NamingContext_var rootContext;

   try {
     // Obtain a reference to the root context of the Name service:
     CORBA::Object_var obj = orb->resolve_initial_references("NameService");

     // Narrow the reference returned.
     rootContext = CosNaming::NamingContext::_narrow(obj);
     if (CORBA::is_nil(rootContext)) {
       cerr << "Failed to narrow the root naming context." << endl;
       return ;
     }
   }
   catch (CORBA::NO_RESOURCES&) {
     cerr << "Caught NO_RESOURCES exception. You must configure omniORB "
      << "with the location" << endl
      << "of the naming service." << endl;
     return ;
   }
   catch (CORBA::ORB::InvalidName&) {
     // This should not happen!
     cerr << "Service required is invalid [does not exist]." << endl;
     return ;
   }

   try {
     // Bind a context called "test" to the root context:

     CosNaming::Name contextName;
     contextName.length();
     contextName[].id   = (const char*) "test";       // string copied
     contextName[].kind = (const char*) "my_context"; // string copied
     // Note on kind: The kind field is used to indicate the type
     // of the object. This is to avoid conventions such as that used
     // by files (name.type -- e.g. test.ps = postscript etc.)

     CosNaming::NamingContext_var testContext;
     try {
       // Bind the context to root.
       testContext = rootContext->bind_new_context(contextName);
     }
     catch(CosNaming::NamingContext::AlreadyBound& ex) {
       // If the context already exists, this exception will be raised.
       // In this case, just resolve the name and assign testContext
       // to the object returned:
       CORBA::Object_var obj = rootContext->resolve(contextName);
       testContext = CosNaming::NamingContext::_narrow(obj);
       if (CORBA::is_nil(testContext)) {
         cerr << "Failed to narrow naming context." << endl;
         return ;
       }
     }

     // Bind objref with name Echo to the testContext:
     CosNaming::Name objectName;
     objectName.length();
     objectName[].id   = (const char*) "Echo";   // string copied
     objectName[].kind = (const char*) "Object"; // string copied

     try {
       testContext->bind(objectName, objref);
     }
     catch(CosNaming::NamingContext::AlreadyBound& ex) {
       testContext->rebind(objectName, objref);
     }
     // Note: Using rebind() will overwrite any Object previously bound
     //       to /test/Echo with obj.
     //       Alternatively, bind() can be used, which will raise a
     //       CosNaming::NamingContext::AlreadyBound exception if the name
     //       supplied is already bound to an object.
   }
   catch (CORBA::TRANSIENT& ex) {
     cerr << "Caught system exception TRANSIENT -- unable to contact the "
          << "naming service." << endl
      << "Make sure the naming server is running and that omniORB is "
      << "configured correctly." << endl;

     return ;
   }
   catch (CORBA::SystemException& ex) {
     cerr << "Caught a CORBA::" << ex._name()
      << " while using the naming service." << endl;
     return ;
   }
   return ;
 }

server.cpp

 // eg3_clt.cc - This is the source code of example 3 used in Chapter 2
 //              "The Basics" of the omniORB user guide.
 //
 //              This is the client. It uses the COSS naming service
 //              to obtain the object reference.
 //
 // Usage: eg3_clt
 //
 //
 //        On startup, the client lookup the object reference from the
 //        COS naming service.
 //
 //        The name which the object is bound to is as follows:
 //              root  [context]
 //               |
 //              text  [context] kind [my_context]
 //               |
 //              Echo  [object]  kind [Object]
 //

 #include "echo.hh"

 #ifdef HAVE_STD
 #  include <iostream>
    using namespace std;
 #else
 #  include <iostream.h>
 #endif

 static CORBA::Object_ptr getObjectReference(CORBA::ORB_ptr orb);

 static void hello(Echo_ptr e)
 {
   if (CORBA::is_nil(e)) {
     cerr << "hello: The object reference is nil!\n" << endl;
     return;
   }

   CORBA::String_var src = (const char*) "Hello!";

   CORBA::String_var dest = e->echoString(src);

   cerr << "I said, \"" << (char*)src << "\"." << endl
        << "The Echo object replied, \"" << (char*)dest <<"\"." << endl;
 }

 //////////////////////////////////////////////////////////////////////

 int
 main (int argc, char **argv)
 {
   try {
     CORBA::ORB_var orb = CORBA::ORB_init(argc, argv);

     CORBA::Object_var obj = getObjectReference(orb);

     Echo_var echoref = Echo::_narrow(obj);

     for (CORBA::ULong count=; count < ; count++)
       hello(echoref);

     orb->destroy();
   }
   catch (CORBA::TRANSIENT&) {
     cerr << "Caught system exception TRANSIENT -- unable to contact the "
          << "server." << endl;
   }
   catch (CORBA::SystemException& ex) {
     cerr << "Caught a CORBA::" << ex._name() << endl;
   }
   catch (CORBA::Exception& ex) {
     cerr << "Caught CORBA::Exception: " << ex._name() << endl;
   }
   return ;
 }

 //////////////////////////////////////////////////////////////////////

 static CORBA::Object_ptr
 getObjectReference(CORBA::ORB_ptr orb)
 {
   CosNaming::NamingContext_var rootContext;

   try {
     // Obtain a reference to the root context of the Name service:
     CORBA::Object_var obj;
     obj = orb->resolve_initial_references("NameService");

     // Narrow the reference returned.
     rootContext = CosNaming::NamingContext::_narrow(obj);

     if (CORBA::is_nil(rootContext)) {
       cerr << "Failed to narrow the root naming context." << endl;
       return CORBA::Object::_nil();
     }
   }
   catch (CORBA::NO_RESOURCES&) {
     cerr << "Caught NO_RESOURCES exception. You must configure omniORB "
      << "with the location" << endl
      << "of the naming service." << endl;
     return CORBA::Object::_nil();
   }
   catch (CORBA::ORB::InvalidName& ex) {
     // This should not happen!
     cerr << "Service required is invalid [does not exist]." << endl;
     return CORBA::Object::_nil();
   }

   // Create a name object, containing the name test/context:
   CosNaming::Name name;
   name.length();

   name[].id   = (const char*) "test";       // string copied
   name[].kind = (const char*) "my_context"; // string copied
   name[].id   = (const char*) "Echo";
   name[].kind = (const char*) "Object";
   // Note on kind: The kind field is used to indicate the type
   // of the object. This is to avoid conventions such as that used
   // by files (name.type -- e.g. test.ps = postscript etc.)

   try {
     // Resolve the name to an object reference.
     return rootContext->resolve(name);
   }
   catch (CosNaming::NamingContext::NotFound& ex) {
     // This exception is thrown if any of the components of the
     // path [contexts or the object] aren't found:
     cerr << "Context not found." << endl;
   }
   catch (CORBA::TRANSIENT& ex) {
     cerr << "Caught system exception TRANSIENT -- unable to contact the "
          << "naming service." << endl
      << "Make sure the naming server is running and that omniORB is "
      << "configured correctly." << endl;
   }
   catch (CORBA::SystemException& ex) {
     cerr << "Caught a CORBA::" << ex._name()
      << " while using the naming service." << endl;
   }
   return CORBA::Object::_nil();
 }

client.cpp

5. 编写makefile，用于生成c++的客户端和服务端

 CXX=g++
 FLAGS=-Wall

 all:server client

 server:server.cpp echoSK.cc echo.hh
     $(CXX) $(FLAGS) -o $@ server.cpp echoSK.cc -lomnithread -lomniORB4

 client:client.cpp echoSK.cc echo.hh
     $(CXX) $(FLAGS) -o $@ client.cpp echoSK.cc -lomnithread -lomniORB4

 clean:
     rm server client

makefile

6. 执行make命令，生成 server 和client 的二进制文件

7. 启动 tnameserv

sudo tnameserv

该命令会同时告诉我们端口号，这里是900

8. 启动服务端

./server -ORBInitRef NameService=corbaloc::localhost:/NameService

9. 启动客户端

./client -ORBInitRef NameService=corbaloc::localhost:/NameService

10. 现在为止，我们已经用 c++ 实现了服务端和客户端，接下来我们用java实现客户端，服务端依然使用之前 make 生成的。

11. 现在用idlj 生成一些必要的 java 文件

idlj echo.idl

12. 编写java客户端，本实验中是 javaclient.java

 //import HelloApp.*;
 import org.omg.CosNaming.*;
 import org.omg.CosNaming.NamingContextPackage.*;
 import org.omg.CORBA.*;

 public class javaclient
 {
   static Echo echoImpl;

   public static void main(String args[])
     {
       try{
         // create and initialize the ORB
     ORB orb = ORB.init(args, null);

         // get the root naming context
         org.omg.CORBA.Object objRef =
         orb.resolve_initial_references("NameService");
         // Use NamingContextExt instead of NamingContext. This is
         // part of the Interoperable naming Service.
         NamingContextExt ncRef = NamingContextExtHelper.narrow(objRef);

         // resolve the Object Reference in Naming
         //String name = "Hello";
         NameComponent name0=new NameComponent("test","my_context");
         NameComponent name1=new NameComponent("Echo","Object");
         echoImpl = EchoHelper.narrow(ncRef.resolve(new NameComponent[]{name0,name1}));

         System.out.println("Obtained a handle on server object: " + echoImpl);
         System.out.println(echoImpl.echoString("Hello"));
         //echoImpl.shutdown();

     } catch (Exception e) {
           System.out.println("ERROR : " + e) ;
       e.printStackTrace(System.out);
       }
     }

 }

javaclient.java

13. 编译java 客户端

javac *.java

14. 执行java客户端

java javaclient -ORBInitRef NameService=corbaloc::localhost:/NameService

15. 附带给出一个脚本，用于删除那些由程序生成的文件，可以用来清理项目

 #!/bin/bash

 rm client
 rm server
 rm *.class
 rm echo.hh
 rm echoSK.cc
 rm _EchoStub.java
 rm EchoHelper.java
 rm EchoHolder.java
 rm EchoOperations.java

rmunneededfile.sh

16. 结束

Trouble shooting：

1. 编译出来c++的server，在运行时出现没有找到.so的问题，于是使用ldd命令找到运行server时缺少的库，实际的.so所在的目录是/usr/local/lib,尝试将该目录添加到PATH环境变量中，发现没有效果（大概寻找.so时搜索的路径不是PATH环境变量），于是在/usr/lib下建了所缺少的.so的符号链接，问题解决。

2. 在ubuntu中，编译omniORB会出现无法找到python头文件的问题，原因是python的头文件存在于单独的包中，名为 libpython2.7-dev。