java rmi 简单例子

//接口

package cn.wsl.rmi.server;

import java.io.IOException;
import java.util.Date;

public interface Hello {

 public String echo(String msg) throws IOException;

 public Date getTime_r() throws Exception;
}

//create remote interface

package cn.wsl.rmi.server;

import java.rmi.Remote;

public interface HelloService extends Remote, Hello {

}

//create remote class

package cn.wsl.rmi.server;

import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.util.Date;

public class HelloServiceImpl implements HelloService {
 private String name;

 public HelloServiceImpl(String name) throws RemoteException {
  this.name = name;
  UnicastRemoteObject.exportObject(this, 0);// 把自身对象导出为远程对象，0是随机监听的端口，其他数字为指定的
 }

 @Override
 public String echo(String msg) throws RemoteException {// RemoteException
               // is IOException `s
               // subclass
  System.out.println(name + " echo() method;");
  return "echo " + name;
 }

 @Override
 public Date getTime_r() throws RemoteException {// RemoteException is
             // Exception `s subclass

  System.out.println(name + ": invoke getTime_r() method;");
  return new Date();
 }

}

//create server program

package cn.wsl.rmi.server;

import javax.naming.Context;
import javax.naming.InitialContext;

public class SimpleServer {
 public static void main(String[] args) {
  try {
   HelloService hello1 = new HelloServiceImpl("hello1");// create
                 // romte
                 // object
   HelloService hello2 = new HelloServiceImpl("hello2");

   Context nameContext = new InitialContext();
   nameContext.rebind("rmi:hello1", hello1);// 注册远程对象，注册名字 以 rmi 开头
   nameContext.rebind("rmi:hello2", hello2);// rebind方法默认绑定到1099端口、、
   System.out.println("bind succes!");
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}

//create client program

package cn.wsl.rmi.client;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NameClassPair;
import javax.naming.NamingEnumeration;

import cn.wsl.rmi.server.HelloService;

public class SimpleClient {

 public static void showRemoteObjects(Context namingContext)
   throws Exception {
  NamingEnumeration<NameClassPair> e = namingContext.list("rmi:");
  while (e.hasMore()) {
   System.out.println(e.next(). getName_r());
  }
 }

 public static void main(String args[]) {
  String url = "rmi://localhost/";
  try {
   Context namingContext = new InitialContext();
   HelloService hello1 = (HelloService) namingContext.lookup(url
     + "hello1");
   HelloService hello2 = (HelloService) namingContext.lookup(url
     + "hello2");
   Class stubClass = hello1. getClass_r();
   System.out.println("hello1 : " + stubClass. getName_r());
   Class[] interfaces = stubClass. getInterfaces_r();
   for (int i = 0; i < interfaces.length; i++) {
    System.out.println("interfaces : " + interfaces[i]. getName_r());
   }
   System.out.println(hello1.echo("hello "));
   System.out.println(hello1. getTime_r());
   System.out.println(hello2.echo("hello "));
   System.out.println(hello2. getTime_r());
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}

运行

结果