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
1 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
1 // eg3_impl.cc - This is the source code of example 3 used in Chapter 2
2 // "The Basics" of the omniORB user guide.
3 //
4 // This is the object implementation.
5 //
6 // Usage: eg3_impl
7 //
8 // On startup, the object reference is registered with the
9 // COS naming service. The client uses the naming service to
10 // locate this object.
11 //
12 // The name which the object is bound to is as follows:
13 // root [context]
14 // |
15 // test [context] kind [my_context]
16 // |
17 // Echo [object] kind [Object]
18 //
19
20 #include "echo.hh"
21
22 #ifdef HAVE_STD
23 # include <iostream>
24 using namespace std;
25 #else
26 # include <iostream.h>
27 #endif
28
29 static CORBA::Boolean bindObjectToName(CORBA::ORB_ptr, CORBA::Object_ptr);
30
31
32 class Echo_i : public POA_Echo
33 {
34 public:
35 inline Echo_i() {}
36 virtual ~Echo_i() {}
37 virtual char* echoString(const char* mesg);
38 };
39
40
41 char* Echo_i::echoString(const char* mesg)
42 {
43 return CORBA::string_dup(mesg);
44 }
45
46 //////////////////////////////////////////////////////////////////////
47
48 int
49 main(int argc, char **argv)
50 {
51 try {
52 CORBA::ORB_var orb = CORBA::ORB_init(argc, argv);
53 CORBA::Object_var obj = orb->resolve_initial_references("RootPOA");
54 PortableServer::POA_var poa = PortableServer::POA::_narrow(obj);
55
56 PortableServer::Servant_var<Echo_i> myecho = new Echo_i();
57
58 PortableServer::ObjectId_var myechoid = poa->activate_object(myecho);
59
60 // Obtain a reference to the object, and register it in
61 // the naming service.
62 obj = myecho->_this();
63
64 CORBA::String_var sior(orb->object_to_string(obj));
65 cout << sior << endl;
66
67 if (!bindObjectToName(orb, obj))
68 return 1;
69
70 PortableServer::POAManager_var pman = poa->the_POAManager();
71 pman->activate();
72
73 orb->run();
74 }
75 catch (CORBA::SystemException& ex) {
76 cerr << "Caught CORBA::" << ex._name() << endl;
77 }
78 catch (CORBA::Exception& ex) {
79 cerr << "Caught CORBA::Exception: " << ex._name() << endl;
80 }
81 return 0;
82 }
83
84 //////////////////////////////////////////////////////////////////////
85
86 static CORBA::Boolean
87 bindObjectToName(CORBA::ORB_ptr orb, CORBA::Object_ptr objref)
88 {
89 CosNaming::NamingContext_var rootContext;
90
91 try {
92 // Obtain a reference to the root context of the Name service:
93 CORBA::Object_var obj = orb->resolve_initial_references("NameService");
94
95 // Narrow the reference returned.
96 rootContext = CosNaming::NamingContext::_narrow(obj);
97 if (CORBA::is_nil(rootContext)) {
98 cerr << "Failed to narrow the root naming context." << endl;
99 return 0;
100 }
101 }
102 catch (CORBA::NO_RESOURCES&) {
103 cerr << "Caught NO_RESOURCES exception. You must configure omniORB "
104 << "with the location" << endl
105 << "of the naming service." << endl;
106 return 0;
107 }
108 catch (CORBA::ORB::InvalidName&) {
109 // This should not happen!
110 cerr << "Service required is invalid [does not exist]." << endl;
111 return 0;
112 }
113
114 try {
115 // Bind a context called "test" to the root context:
116
117 CosNaming::Name contextName;
118 contextName.length(1);
119 contextName[0].id = (const char*) "test"; // string copied
120 contextName[0].kind = (const char*) "my_context"; // string copied
121 // Note on kind: The kind field is used to indicate the type
122 // of the object. This is to avoid conventions such as that used
123 // by files (name.type -- e.g. test.ps = postscript etc.)
124
125 CosNaming::NamingContext_var testContext;
126 try {
127 // Bind the context to root.
128 testContext = rootContext->bind_new_context(contextName);
129 }
130 catch(CosNaming::NamingContext::AlreadyBound& ex) {
131 // If the context already exists, this exception will be raised.
132 // In this case, just resolve the name and assign testContext
133 // to the object returned:
134 CORBA::Object_var obj = rootContext->resolve(contextName);
135 testContext = CosNaming::NamingContext::_narrow(obj);
136 if (CORBA::is_nil(testContext)) {
137 cerr << "Failed to narrow naming context." << endl;
138 return 0;
139 }
140 }
141
142 // Bind objref with name Echo to the testContext:
143 CosNaming::Name objectName;
144 objectName.length(1);
145 objectName[0].id = (const char*) "Echo"; // string copied
146 objectName[0].kind = (const char*) "Object"; // string copied
147
148 try {
149 testContext->bind(objectName, objref);
150 }
151 catch(CosNaming::NamingContext::AlreadyBound& ex) {
152 testContext->rebind(objectName, objref);
153 }
154 // Note: Using rebind() will overwrite any Object previously bound
155 // to /test/Echo with obj.
156 // Alternatively, bind() can be used, which will raise a
157 // CosNaming::NamingContext::AlreadyBound exception if the name
158 // supplied is already bound to an object.
159 }
160 catch (CORBA::TRANSIENT& ex) {
161 cerr << "Caught system exception TRANSIENT -- unable to contact the "
162 << "naming service." << endl
163 << "Make sure the naming server is running and that omniORB is "
164 << "configured correctly." << endl;
165
166 return 0;
167 }
168 catch (CORBA::SystemException& ex) {
169 cerr << "Caught a CORBA::" << ex._name()
170 << " while using the naming service." << endl;
171 return 0;
172 }
173 return 1;
174 }
server.cpp
1 // eg3_clt.cc - This is the source code of example 3 used in Chapter 2
2 // "The Basics" of the omniORB user guide.
3 //
4 // This is the client. It uses the COSS naming service
5 // to obtain the object reference.
6 //
7 // Usage: eg3_clt
8 //
9 //
10 // On startup, the client lookup the object reference from the
11 // COS naming service.
12 //
13 // The name which the object is bound to is as follows:
14 // root [context]
15 // |
16 // text [context] kind [my_context]
17 // |
18 // Echo [object] kind [Object]
19 //
20
21 #include "echo.hh"
22
23 #ifdef HAVE_STD
24 # include <iostream>
25 using namespace std;
26 #else
27 # include <iostream.h>
28 #endif
29
30 static CORBA::Object_ptr getObjectReference(CORBA::ORB_ptr orb);
31
32 static void hello(Echo_ptr e)
33 {
34 if (CORBA::is_nil(e)) {
35 cerr << "hello: The object reference is nil!\n" << endl;
36 return;
37 }
38
39 CORBA::String_var src = (const char*) "Hello!";
40
41 CORBA::String_var dest = e->echoString(src);
42
43 cerr << "I said, \"" << (char*)src << "\"." << endl
44 << "The Echo object replied, \"" << (char*)dest <<"\"." << endl;
45 }
46
47 //////////////////////////////////////////////////////////////////////
48
49 int
50 main (int argc, char **argv)
51 {
52 try {
53 CORBA::ORB_var orb = CORBA::ORB_init(argc, argv);
54
55 CORBA::Object_var obj = getObjectReference(orb);
56
57 Echo_var echoref = Echo::_narrow(obj);
58
59 for (CORBA::ULong count=0; count < 10; count++)
60 hello(echoref);
61
62 orb->destroy();
63 }
64 catch (CORBA::TRANSIENT&) {
65 cerr << "Caught system exception TRANSIENT -- unable to contact the "
66 << "server." << endl;
67 }
68 catch (CORBA::SystemException& ex) {
69 cerr << "Caught a CORBA::" << ex._name() << endl;
70 }
71 catch (CORBA::Exception& ex) {
72 cerr << "Caught CORBA::Exception: " << ex._name() << endl;
73 }
74 return 0;
75 }
76
77 //////////////////////////////////////////////////////////////////////
78
79 static CORBA::Object_ptr
80 getObjectReference(CORBA::ORB_ptr orb)
81 {
82 CosNaming::NamingContext_var rootContext;
83
84 try {
85 // Obtain a reference to the root context of the Name service:
86 CORBA::Object_var obj;
87 obj = orb->resolve_initial_references("NameService");
88
89 // Narrow the reference returned.
90 rootContext = CosNaming::NamingContext::_narrow(obj);
91
92 if (CORBA::is_nil(rootContext)) {
93 cerr << "Failed to narrow the root naming context." << endl;
94 return CORBA::Object::_nil();
95 }
96 }
97 catch (CORBA::NO_RESOURCES&) {
98 cerr << "Caught NO_RESOURCES exception. You must configure omniORB "
99 << "with the location" << endl
100 << "of the naming service." << endl;
101 return CORBA::Object::_nil();
102 }
103 catch (CORBA::ORB::InvalidName& ex) {
104 // This should not happen!
105 cerr << "Service required is invalid [does not exist]." << endl;
106 return CORBA::Object::_nil();
107 }
108
109 // Create a name object, containing the name test/context:
110 CosNaming::Name name;
111 name.length(2);
112
113 name[0].id = (const char*) "test"; // string copied
114 name[0].kind = (const char*) "my_context"; // string copied
115 name[1].id = (const char*) "Echo";
116 name[1].kind = (const char*) "Object";
117 // Note on kind: The kind field is used to indicate the type
118 // of the object. This is to avoid conventions such as that used
119 // by files (name.type -- e.g. test.ps = postscript etc.)
120
121 try {
122 // Resolve the name to an object reference.
123 return rootContext->resolve(name);
124 }
125 catch (CosNaming::NamingContext::NotFound& ex) {
126 // This exception is thrown if any of the components of the
127 // path [contexts or the object] aren‘t found:
128 cerr << "Context not found." << endl;
129 }
130 catch (CORBA::TRANSIENT& ex) {
131 cerr << "Caught system exception TRANSIENT -- unable to contact the "
132 << "naming service." << endl
133 << "Make sure the naming server is running and that omniORB is "
134 << "configured correctly." << endl;
135 }
136 catch (CORBA::SystemException& ex) {
137 cerr << "Caught a CORBA::" << ex._name()
138 << " while using the naming service." << endl;
139 }
140 return CORBA::Object::_nil();
141 }
client.cpp
5. 编写makefile，用于生成c++的客户端和服务端
1 CXX=g++ 2 FLAGS=-Wall 3 4 all:server client 5 6 server:server.cpp echoSK.cc echo.hh 7 $(CXX) $(FLAGS) -o [email protected] server.cpp echoSK.cc -lomnithread -lomniORB4 8 9 client:client.cpp echoSK.cc echo.hh 10 $(CXX) $(FLAGS) -o [email protected] client.cpp echoSK.cc -lomnithread -lomniORB4 11 12 clean: 13 rm server client 14 15
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:900/NameService
9. 启动客户端
./client -ORBInitRef NameService=corbaloc::localhost:900/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
1 //import HelloApp.*;
2 import org.omg.CosNaming.*;
3 import org.omg.CosNaming.NamingContextPackage.*;
4 import org.omg.CORBA.*;
5
6 public class javaclient
7 {
8 static Echo echoImpl;
9
10 public static void main(String args[])
11 {
12 try{
13 // create and initialize the ORB
14 ORB orb = ORB.init(args, null);
15
16 // get the root naming context
17 org.omg.CORBA.Object objRef =
18 orb.resolve_initial_references("NameService");
19 // Use NamingContextExt instead of NamingContext. This is
20 // part of the Interoperable naming Service.
21 NamingContextExt ncRef = NamingContextExtHelper.narrow(objRef);
22
23 // resolve the Object Reference in Naming
24 //String name = "Hello";
25 NameComponent name0=new NameComponent("test","my_context");
26 NameComponent name1=new NameComponent("Echo","Object");
27 echoImpl = EchoHelper.narrow(ncRef.resolve(new NameComponent[]{name0,name1}));
28
29 System.out.println("Obtained a handle on server object: " + echoImpl);
30 System.out.println(echoImpl.echoString("Hello"));
31 //echoImpl.shutdown();
32
33 } catch (Exception e) {
34 System.out.println("ERROR : " + e) ;
35 e.printStackTrace(System.out);
36 }
37 }
38
39 }
javaclient.java
13. 编译java 客户端
javac *.java
14. 执行java客户端
java javaclient -ORBInitRef NameService=corbaloc::localhost:900/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
1 #!/bin/bash 2 3 rm client 4 rm server 5 rm *.class 6 rm echo.hh 7 rm echoSK.cc 8 rm _EchoStub.java 9 rm EchoHelper.java 10 rm EchoHolder.java 11 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。
时间： 2024-11-01 18:47:50