第一个RMI程序!

接口:

import java.rmi.*;
public interface PerfectTimeI extends Remote{
public String GetTime() throws RemoteException;
}

服务提供:

import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
import java.io.*;
import java.net.*;

public class myServer extends  UnicastRemoteObject
 implements PerfectTimeI{
 public String GetTime()throws RemoteException
 {
  return Long.toString(System.currentTimeMillis());
 }
 public myServer() throws RemoteException
 {
  //super();
 }
 public static void main(String[] args) throws Exception  {
  myServer s=new myServer();
  Naming.rebind("/myServer",s);
  System.out.println("Ready to do time");
 }

}

客户端:

import java.rmi.*;
import java.rmi.registry.*;

public class myClient{
 public static void main(String[] args)  {
   System.setSecurityManager(new RMISecurityManager());

      try {

          PerfectTimeI t = (PerfectTimeI) Naming.lookup("/myServer");

         for (int i = 0; i < 10; i++) {

             System.out.println("PerfectTime:" + t.GetTime());

         }

      } catch (Exception e) {

          e.printStackTrace();

      }

 }
}
因为rmi有安全限制，所以在客户端必须建立一个策略文件。假设名为client.policy 

grant {
// Allow everything for now
permission java.security.AllPermission;
};

命令行:
第一个窗口:

d:/javac *.java

d:/rmic -v1.1 -d d: myServer

d:/start rmiregistry

第二个窗口:

d:/java myServer 

第三个窗口:

d:/java myClient  不行

d:/start java -Djava.security.policy=client.policy myclient