CORBA版HelloWorld

注：文章转自：

http://lavasoft.blog.51cto.com/62575/240268/

一、定义IDL

module HelloApp{

interface Hello{

string sayHello();

oneway
void shutdown();

};

};

没有IDL的专门的开发工具，写起来容易出错，而且不美观，IDEA勉强支持语法高亮，但不支持格式化和语法校验！

二、从IDL生成存根

进入IDL文件存放目录，然后执行：idlj -fall Hello.idl



会生成一批Java文件：

helloCorba\src\HelloApp

HelloPOA.java

_HelloStub.java

HelloHolder.java

HelloHelper.java

Hello.java

HelloOperations.java

三、实现IDL接口，开发服务端程序

import HelloApp.Hello;

import HelloApp.HelloHelper;

import HelloApp.HelloPOA;

import org.omg.CORBA.ORB;

import org.omg.CosNaming.NameComponent;

import org.omg.CosNaming.NamingContextExt;

import org.omg.CosNaming.NamingContextExtHelper;

import org.omg.PortableServer.POA;

import org.omg.PortableServer.POAHelper;

class HelloImpl
extends HelloPOA {

private ORB orb;

public
void setORB(ORB orb_val) {

orb = orb_val;

}

// implement sayHello() method

public String sayHello() {

return
"\nHello world !!\n";

}

// implement shutdown() method

public
void shutdown() {

orb.shutdown(
false);

}

}

public
class HelloServer {

public
static
void main(String args[]) {

try {

//创建一个ORB实例

ORB orb = ORB.init(args,
null);

//得到一个RootPOA的引用，并激活POAManager

POA rootpoa = POAHelper.narrow(orb.resolve_initial_references(
"RootPOA"));

rootpoa.the_POAManager().activate();

// create servant and register it with the ORB

//创建一个HelloImpl实例（servant），并注册到ORB上

HelloImpl helloImpl =
new HelloImpl();

helloImpl.setORB(orb);

//从服务中得到对象的引用

org.omg.CORBA.Object ref = rootpoa.servant_to_reference(helloImpl);

Hello href = HelloHelper.narrow(ref);

//得到一个根名称的上下文

org.omg.CORBA.Object objRef = orb.resolve_initial_references(
"NameService");

// Use NamingContextExt which is part of the Interoperable

// Naming Service (INS) specification.

NamingContextExt ncRef = NamingContextExtHelper.narrow(objRef);

//在命名上下文中绑定这个对象

String name =
"Hello";

NameComponent path[] = ncRef.to_name(name);

ncRef.rebind(path, href);

System.out.println(
"HelloServer ready and waiting ...");

//启动线程服务，等待客户端的调用

orb.run();

}
catch (Exception e) {

System.err.println(
"ERROR: " + e);

e.printStackTrace(System.out);

}

System.out.println(
"HelloServer Exiting ...");

}

}

四、实现CORBA的客户端

import HelloApp.Hello;

import HelloApp.HelloHelper;

import org.omg.CORBA.ORB;

import org.omg.CosNaming.NamingContextExt;

import org.omg.CosNaming.NamingContextExtHelper;

public
class HelloClient {

static Hello helloImpl;

public
static
void main(String args[]) {

try {

//创建一个ORB实例

ORB orb = ORB.init(args,
null);

//获取根名称上下文

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);

//从命名上下文中获取接口实现对象

String name =
"Hello";

helloImpl = HelloHelper.narrow(ncRef.resolve_str(name));

//调用接口对象的方法

System.out.println(
"Obtained a handle on server object: " + helloImpl);

System.out.println(helloImpl.sayHello());

helloImpl.shutdown();

}
catch (Exception e) {

System.out.println(
"ERROR : " + e);

e.printStackTrace(System.out);

}

}

}

五、运行

1）运行CORBA服务

orbd -ORBInitialPort 1050 -ORBInitialHost 192.168.14.117

2）运行CORBA应用的服务端

java HelloServer -ORBInitialPort 1050

输出：

HelloServer ready and waiting ...

HelloServer Exiting ...

3）运行CORBA应用的客户端

java HelloClient -ORBInitialHost 192.168.14.117 -ORBInitialPort 1050

Obtained a handle on server object: IOR:000000000000001749444c3a48656c6c6f4170702f48656c6c6f3a312e30000000000001000000000000008a000102000000000f3139322e3136382e31342e313137000006db000000000031afabcb00000000206d3bb80000000001000000000000000100000008526f6f74504f410000000008000000010000000014000000000000020000000100000020000000000001000100000002050100010001002000010109000000010001010000000026000000020002

Hello world !!

orbd.exe

用法：orbd <选项>
其中，<选项> 包括：
-port 启动 ORBD 的激活端口，缺省值为 1049 (可选)
-defaultdb ORBD 文件的目录，缺省值为 "./orb.db" (可选)
-serverid ORBD 的服务器标识符，缺省值为 1 (可选)
-ORBInitialPort 初始端口（必需）
-ORBInitialHost 初始主机名称（必需）