走在架構(gòu)師的大道上 Jack.Wang's home

       1）首先要熟悉idl語(yǔ)言，這個(gè)是專門進(jìn)行接口設(shè)計(jì)的語(yǔ)言，它與java沒(méi)關(guān)系，有自己的語(yǔ)法，具體的規(guī)則需要大家自己再網(wǎng)上研究，這里不多說(shuō)了（或者訪問(wèn)如下網(wǎng)站詳細(xì)察看http://www.iona.com/support/docs/manuals/orbix/33/html/orbix33cxx_pguide/IDL.html）。

module HelloApp
{
  
 interface Hello
    {
        string sayHello();
        oneway void shutdown();
     };
};

這 里定義了一個(gè)簡(jiǎn)單的interface, 將其保存為hello.idl, 然后再dos命令框里面輸入 idlj.exe -fall hello.idl 編譯。之后會(huì)出現(xiàn)一個(gè)叫做HelloApp的目錄，corba就是通過(guò)這個(gè)目錄里面的類來(lái)進(jìn)行c-s之間的數(shù)據(jù)溝通。

      2）下一步，就是我們的server端：

// A server for the Hello object

import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import org.omg.PortableServer.*;
import org.omg.PortableServer.POA;
import java.util.Properties;

public class HelloServer {

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

      // get reference to rootpoa & activate the POAManager
      POA rootpoa =
        (POA)orb.resolve_initial_references("RootPOA");
      rootpoa.the_POAManager().activate();

      // create servant and register it with the ORB
      HelloImpl helloImpl = new HelloImpl();
      helloImpl.setORB(orb);

      // get object reference from the servant
      org.omg.CORBA.Object ref =
        rootpoa.servant_to_reference(helloImpl);

      // and cast the reference to a CORBA reference
      Hello href = HelloHelper.narrow(ref);
  
      // get the root naming context
      // NameService invokes the transient name service
      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);

      // bind the Object Reference in Naming
      String name = "Hello1";
      NameComponent path[] = ncRef.to_name( name );
      ncRef.rebind(path, href);

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

      // wait for invocations from clients
      orb.run();
    }
 
      catch (Exception e) {
        System.err.println("ERROR: " + e);
        e.printStackTrace(System.out);
      }
  
      System.out.println("HelloServer Exiting ...");
 
  } //end main
} // end class

將其保存為HelloServer.java.放在剛才的hello.idl的目錄。編譯這個(gè)文件就不多說(shuō)了。

       3）還記得在hello中定義的interface嗎？我們需要對(duì)自己定義的接口中的方法進(jìn)行實(shí)現(xiàn)，因此HelloImp.java

// The servant -- object implementation -- for the Hello
// example.  Note that this is a subclass of HelloPOA, whose
// source file is generated from the compilation of
// Hello.idl using j2idl.

import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import org.omg.PortableServer.*;
import org.omg.PortableServer.POA;

import java.util.Properties;

class HelloImpl extends HelloPOA //必須繼承這個(gè)類，在helloApp目錄中已自動(dòng)生成

 {
  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);
  }
} //end class
同樣放在server所在目錄中。

      4）接下來(lái)是客戶端（HelloClient.java）：

// A sample Java IDL object client application.
import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;

public class HelloClient
{
  static Hello helloImpl;
  String [] x=new String[6];
  public static void main(String args[]){
     try{
        // create and initialize the ORB
      ORB orb = ORB.init(args, null);

        System.out.println("ORB initialised\n");

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

        // Use NamingContextExt instead of NamingContext,
        // part of the Interoperable naming Service. 
        NamingContextExt ncRef =
          NamingContextExtHelper.narrow(objRef);
 
        // resolve the Object Reference in Naming
        String name = "Hello1";
        helloImpl =
          HelloHelper.narrow(ncRef.resolve_str(name));

        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);
   }
  } //end main

} // end class

這個(gè)文件最好放在一個(gè)新建的目錄，已表示和server有區(qū)別，放在一起也沒(méi)有關(guān)系。如果分開的話，記著把HelloApp這個(gè)目錄復(fù)制到client的目錄來(lái)。

5）好啦！已經(jīng)可以開始爽了，我們編譯所有的java文件

6）再dos窗口輸入orbd.exe –ORBInitialPort 1234（端口號(hào)可以自定義，但是記得s-c要保持一致）,啟動(dòng)corba服務(wù)。

7）啟動(dòng)服務(wù)器：java HelloServer –ORBInitialPort 1234 –ORBInitialHost localhost

8）啟動(dòng)客戶端：java HelloClient –ORBInitialPort 1234 –ORBInitialHost localhost

9）嚴(yán)格執(zhí)行上述過(guò)程是應(yīng)該直接成功的。 已經(jīng)經(jīng)過(guò)測(cè)試。