Java java.rmi.Naming用法及代碼示例

// Java Program to create a registry
// Server's Side 
// Importing java.rmi package to enable object of one JVM
// to invoke methods on object in another JVM
import java.rmi.*;
import java.rmi.AlreadyBoundException;
import java.rmi.Naming;
import java.rmi.NotBoundException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.*;
// Interface
// creating remote interface
interface demo extends Remote {
    public String msg(String msg) throws RemoteException;
}
// Class 1
// Helper Class
class demoRemote
    extends UnicastRemoteObject implements demo {
    demoRemote() throws RemoteException { super(); }
    // @Override
    public String msg(String msg) throws RemoteException
    {
        // Display message only
        System.out.println("GeeksForGeeks");
        return null;
    }
}
// Class 2
// Main class
public class GFG_Server {
    // Main driver method
    public static void main(String args[])
        throws RemoteException, NotBoundException,
               AlreadyBoundException
    {
        // Try block to check for exceptions
        try {
            // Creating a new registry by creating
            // an object of Registry class
            Registry registry
                = LocateRegistry.createRegistry(3000);
            demo obj = new demoRemote();
            // binding obj to remote registry
            Naming.bind("rmi://localhost:3000"
                            + "/geeksforgeeks",
                        (Remote)obj);
            // Display message when program
            // is executed successfully
            System.out.println(
                "registry created successfully");
        }
        // Catch block to handle the exceptions
        catch (Exception e) {
            // Getting the name of the exception using
            // the toString() method over exception object
            System.err.println(e.toString());
        }
    }
}

// Java Program to look for the object
// Client Side 
// Importing java.rmi package to enable object of one JVM
// to invoke methods on object in another JVM
import java.rmi.*;
// Main class
public class GFG_Client {
    // Main driver method
    public static void main(String args[])
    {
        // try block to check for exceptions
        try {
            // Looking for object in remote registry
            demo client = (demo)Naming.lookup(
                "rmi://localhost:3000/obj");
            // Print and display the client message
            System.out.println(client.msg());
        }
        // Catch block to handle the exception
        catch (Exception e) {
        }
    }
}