Java源码：CORBA入门

/ns/wz/comp/data/20020809011942.htm

Java源码：CORBA入门


本文出自:www.chinajavaworld.com 作者: jdeveloper

Below is a simple example of a CORBA program
download the source file

1. produce a idl file like this
hello.idl
module HelloApp {
interface Hello {
string sayHello();
};
};

2. produce stub and skeleton files through idltojava.exe
idltojava hello.idl
idltojava is now named as idlj.exe and is included in the JDK.

3. write a server program like this

// HelloServer.java

import HelloApp.*;

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

import java.io.*;
class HelloServant extends _HelloImplBase
{
public String sayHello()
{
return "\nHello world !!\n";
}

}

public class HelloServer {

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

// create servant and register it with the ORB
HelloServant helloRef = new HelloServant();
orb.connect(helloRef);

// get the root naming context
org.omg.CORBA.Object objRef =
orb.resolve_initial_references("NameService");
NamingContext ncRef = NamingContextHelper.narrow(objRef);

// bind the Object Reference in Naming
NameComponent nc = new NameComponent("Hello", "");
NameComponent path[] = {nc};
ncRef.rebind(path, helloRef);

// wait for invocations from clients
java.lang.Object sync = new java.lang.Object();
synchronized (sync) {
sync.wait();
}

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

4. write a client program like this
// HelloClient.java
import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CORBA.*;

public class HelloClient
{
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");
NamingContext ncRef = NamingContextHelper.narrow(objRef);
// test
System.out.println("OK..");
// resolve the Object Reference in Naming
NameComponent nc = new NameComponent("Hello", "");
NameComponent path[] = {nc};
Hello helloRef = HelloHelper.narrow(ncRef.resolve(path));

// call the Hello server object and print results
//String oldhello = helloRef.lastMessage();
//System.out.println(oldhello);
String Hello = helloRef.sayHello();
System.out.println(Hello);

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

5. complie these files

javac *.java HelloApp/*.java

6. run the application

a. first you've to run the Name Service prior to the others likethis
c:\>tnameserv
b. run server
c:\>java HelloServer
c. run client
c:\>java HelloClient