我在 CORBA 中用 Java 和 C++ 创建了一个简单的应用程序，客户端-服务器应用程序，看看：
interface Task
{
string getThingToDo();
};
#include "Task.idl"
interface Employee
{
typedef sequence <Task> tasks;
string getLastname();
Task getTask(in short id);
};
#include "Employee.idl"
interface Work
{
Employee getEmployee(in short id);
};
TaskImpl.h和TaskImpl.cpp：
#include "Task.hh"
class TaskImpl : public POA_Task
{
private:
CORBA::String_var thingToDo;
public:
TaskImpl(const char* thingToDo);
char* getThingToDo();
};
#include "TaskImpl.h"
TaskImpl::TaskImpl(const char* thingToDo)
{
this->thingToDo = CORBA::string_dup(thingToDo);
}
char* TaskImpl::getThingToDo()
{
return CORBA::string_dup(this->thingToDo.in());
}
EmployeeImpl.h和EmployeeImpl.cpp：
#include "Employee.hh"
#include "TaskImpl.h"
class EmployeeImpl : public POA_Employee
{
private:
CORBA::String_var lastname;
int id;
Employee::tasks thingsToDo;
public:
EmployeeImpl(const char* lastname, int id);
char* getLastname();
Task_ptr getTask(::CORBA::Short id);
};
#include "EmployeeImpl.h"
EmployeeImpl::EmployeeImpl(const char* lastname, int id)
{
this->lastname = CORBA::string_dup(lastname);
this->id = id;
this->thingsToDo.length(3);
TaskImpl *t1, *t2, *t3;
t1 = new TaskImpl("Print all the documents");
t2 = new TaskImpl("Write the report");
t3 = new TaskImpl("Make backup");
this->thingsToDo[0] = t1->_this();
this->thingsToDo[1] = t2->_this();
this->thingsToDo[2] = t3->_this();
}
char* EmployeeImpl::getLastname()
{
return CORBA::string_dup(this->lastname.in());
}
Task_ptr EmployeeImpl::getTask(::CORBA::Short id)
{
return Task::_duplicate(this->thingsToDo[id-1]);
}
WorkImpl.h和WorkImpl.cpp：
#include "Work.hh"
#include <vector>
#include "EmployeeImpl.h"
using namespace std;
class WorkImpl : public POA_Work
{
private:
vector<EmployeeImpl> employees;
public:
WorkImpl();
Employee_ptr getEmployee(::CORBA::Short id);
};
#include "WorkImpl.h"
WorkImpl::WorkImpl()
{
EmployeeImpl ei1(CORBA::string_dup("Doe"), 1);
EmployeeImpl ei2(CORBA::string_dup("Smith"), 2);
EmployeeImpl ei3(CORBA::string_dup("Brown"), 3);
employees.push_back(ei1);
employees.push_back(ei2);
employees.push_back(ei3);
}
Employee_ptr WorkImpl::getEmployee(::CORBA::Short id)
{
return employees[id]._this();
}
服务器.cpp：
#include "WorkImpl.h"
#include <omniORB4/CORBA.h>
#include <omniORB4/Naming.hh>
#include <iostream>
using std::cout;
using std::cerr;
int main(int argc, char **argv)
{
try
{
CORBA::ORB_ptr serverORB = CORBA::ORB_init(argc, argv);
CORBA::Object_var myPOAObj = serverORB->resolve_initial_references("RootPOA");
PortableServer::POA_var myPOA = PortableServer::POA::_narrow(myPOAObj);
PortableServer::POAManager_var myManager = myPOA->the_POAManager();
myManager->activate();
WorkImpl *work = new WorkImpl();
try
{
CORBA::Object_var nameServiceObj = serverORB->resolve_initial_references("NameService");
if(!CORBA::is_nil(nameServiceObj))
{
CosNaming::NamingContext_ptr namingContext = CosNaming::NamingContext::_narrow(nameServiceObj);
CosNaming::Name serviceName;
serviceName.length(1);
serviceName[0].id = CORBA::string_dup("WorkService");
namingContext->rebind(serviceName, work->_this());
cout << "WorkService is running ...\n";
}
}catch(CosNaming::NamingContext::NotFound&){
cerr << "CosNaming::NamingContext::NotFound\n";
}catch(CosNaming::NamingContext::InvalidName&){
cerr << "CosNaming::NamingContext::InvalidName\n";
}catch(CosNaming::NamingContext::CannotProceed&){
cerr << "CosNaming::NamingContext::CannotProceed\n";
}
serverORB->run();
delete work;
serverORB->destroy();
}catch(CORBA::SystemException&){
cerr << "Caught CORBA::SystemException\n";
}catch(CORBA::Exception&){
cerr << "Caught CORBA::Exception \n";
}catch(omniORB::fatalException &fe){
cerr << "Caught omniORB::fatalException\n";
cerr << "File: " << fe.file() << "\n";
cerr << "Line: " << fe.line() << "\n";
cerr << "Msg: " << fe.errmsg() << "\n";
}catch(...){
cerr << "Caught unknown exception\n";
}
return 0;
}
客户端.java：
package OtherPackage;
import java.util.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import java.io.*;
public class Client
{
public static void main(String [] args)
{
try
{
org.omg.CORBA.ORB clientORB = org.omg.CORBA.ORB.init(args, null);
if (clientORB == null)
{
System.out.println("Problem while creating ORB");
System.exit(1);
}
org.omg.CORBA.Object objRef = clientORB.resolve_initial_references("NameService");
NamingContextExt ncRef = NamingContextExtHelper.narrow(objRef);
Work work = WorkHelper.narrow(ncRef.resolve_str("WorkService"));
Employee e = work.getEmployee((short)1);
System.out.println(e.getLastname());
Task t = e.getTask((short)1);
System.out.println(t.getThingToDo());
}catch(Exception e){ System.out.println(e.getMessage());
}
}
}
当我有这样的EmployeeImpl.cpp时：
#include "EmployeeImpl.h"
EmployeeImpl::EmployeeImpl(const char* lastname, int id)
{
this->lastname = CORBA::string_dup(lastname);
this->id = id;
this->thingsToDo.length(3);
TaskImpl *t1, *t2, *t3;
t1 = new TaskImpl("Print all the documents");
t2 = new TaskImpl("Write the report");
t3 = new TaskImpl("Make backup");
this->thingsToDo[0] = Task::_duplicate(t1->_this());
this->thingsToDo[1] = Task::_duplicate(t2->_this());
this->thingsToDo[2] = Task::_duplicate(t3->_this());
}
char* EmployeeImpl::getLastname()
{
return CORBA::string_dup(this->lastname.in());
}
Task_ptr EmployeeImpl::getTask(::CORBA::Short id)
{
return this->thingsToDo[id-1]._retn();
}
我第一次运行客户，我看到：
Smith
Print all the documents
哪个是对的。但是当我第二次（和第三次，等等......）运行我的客户时，我看到：
Smith
null
问题出在哪里？我想了很多，又写了EmployeeImpl.cpp：
#include "EmployeeImpl.h"
EmployeeImpl::EmployeeImpl(const char* lastname, int id)
{
this->lastname = CORBA::string_dup(lastname);
this->id = id;
this->thingsToDo.length(3);
TaskImpl *t1, *t2, *t3;
t1 = new TaskImpl("Print all the documents");
t2 = new TaskImpl("Write the report");
t3 = new TaskImpl("Make backup");
this->thingsToDo[0] = t1->_this();
this->thingsToDo[1] = t2->_this();
this->thingsToDo[2] = t3->_this();
}
char* EmployeeImpl::getLastname()
{
return CORBA::string_dup(this->lastname.in());
}
Task_ptr EmployeeImpl::getTask(::CORBA::Short id)
{
return Task::_duplicate(this->thingsToDo[id-1]);
}
现在一切似乎都很好，每次我运行客户端时。但我不确定它是否以 CORBA 方式好。有什么建议么？
使用这些命令编译和运行服务器和客户端文件（我在 Kubuntu 12.04 上使用 omniORB 4.1.6 和 default-jdk 包）：
Compile (and run) server files (just copy and paste):
g++ -c *.cpp -I$OMNIORB_HOME/include -I$OMNIORB_HOME/include/omniORB4
g++ -c *.cc -I$OMNIORB_HOME/include -I$OMNIORB_HOME/include/omniORB4
g++ -o Server Server.o EmployeeSK.o WorkSK.o WorkImpl.o EmployeeImpl.o TaskImpl.o TaskSK.o -L$OMNIORB_HOME/lib -lomnithread -lomniORB4
./Server -ORBInitRef NameService=corbaloc::localhost:2809/NameService
Compile (and run) client files (just copy and paste):
cd EmployeePackage; javac -cp .. *.java
cd OtherPackage; javac -cp .. *.java
cd java; java OtherPackage.Client -ORBInitRef NameService=corbaloc::localhost:2809/NameService