RMI入门

不考虑使用RMI plugin for eclipse插件。

1. 环境：

eclipse 3.6.2

jdk 1.6.0.24

2.一个简单的demo设计：

2.1

2.2

2.2.1 IHello.java

注意：接口 extends Remote；方法throws RemoteException

/**
 *  Copyright(c) 2010-2011 Yan.Dev. All Rights Reserved.
 */
package com.yan.dev.rmi.server.service;

import java.rmi.Remote;
import java.rmi.RemoteException;

/**
 * Comment for IHello.java
 * 
 * @author <a href="mailto:[e-mail]">yan.dev</a>
 * 
 * @blog:<a href="http://yan-dev.iteye.com"><b>yan.dev's Blog</b></a>
 * @version 1.0
 * @time 2011-3-21 下午04:10:44
 */
public interface IHello extends Remote {
	public void sayHello()throws RemoteException;

}

 

2.2.2 HelloImpl.java

注意：extends UnicastRemoteObject；无参构造函数

/**
 *  Copyright(c) 2010-2011 Yan.Dev. All Rights Reserved.
 */
package com.yan.dev.rmi.server.service.impl;

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

import com.yan.dev.rmi.server.service.IHello;

/**
 * Comment for HelloImpl.java
 * 
 * @author <a href="mailto:[e-mail]">yan.dev</a>
 * 
 * @blog:<a href="http://yan-dev.iteye.com"><b>yan.dev's Blog</b></a>
 * @version 1.0
 * @time 2011-3-21 下午04:13:28
 */
public class HelloImpl extends UnicastRemoteObject implements IHello {
	/**
	 * @throws RemoteException
	 */
	public HelloImpl() throws RemoteException {
		super();
	}

	@Override
	public void sayHello() {
		System.out.println("ok");
	}

}

2.2.3 Server.java

注意：localhost可以替换为server的ip地址

/**
 *  Copyright(c) 2010-2011 Yan.Dev. All Rights Reserved.
 */
package com.yan.dev.rmi.server;

import java.net.MalformedURLException;
import java.rmi.AlreadyBoundException;
import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;

import com.yan.dev.rmi.server.service.IHello;
import com.yan.dev.rmi.server.service.impl.HelloImpl;

/**
 * Comment for Server.java
 * 
 * @author <a href="mailto:[e-mail]">yan.dev</a>
 * 
 * @blog:<a href="http://yan-dev.iteye.com"><b>yan.dev's Blog</b></a>
 * @version 1.0
 * @time 2011-3-21 下午04:11:34
 */
public class Server {
	public static void main(String[] args) {
		int port =1234;
		try {
			LocateRegistry.createRegistry(port);
			// 创建一个远程对象
			IHello hello = new HelloImpl();
			Naming.bind("//localhost:"+port+"/hello", hello);
			System.out.println("Server start succeed, listening...");
		} catch (RemoteException e) { 
			e.printStackTrace();
		} catch (MalformedURLException e) { 
			e.printStackTrace();
		} catch (AlreadyBoundException e) { 
			e.printStackTrace();
		}
	}
}

2.2.4 Client.java

注意：loalhost与server的ip地址一致

 

/**
 *  Copyright(c) 2010-2011 Yan.Dev. All Rights Reserved.
 */
package com.yan.dev.rmi.client;

import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.NotBoundException;
import java.rmi.RemoteException;

import com.yan.dev.rmi.server.service.IHello;

/**
 * Comment for Client.java
 *
 * @author <a href="mailto:[e-mail]">yan.dev</a>
 * 
 * @blog:<a href="http://yan-dev.iteye.com"><b>yan.dev's Blog</b></a>
 * @version 1.0
 * @time 2011-3-21 下午04:17:12
 */
public class Client {

	/**
	 * @param args
	 */
	public static void main(String[] args) { 
		try {
			IHello hello = (IHello) Naming.lookup("rmi://localhost:1234/hello");
			hello.sayHello();
		} catch (MalformedURLException e) { 
			e.printStackTrace();
		} catch (RemoteException e) { 
			e.printStackTrace();
		} catch (NotBoundException e) { 
			e.printStackTrace();
		}
	}

}

3运行

运行Server，

 运行Client

 

 

 

3.1本机

 

 

3.2远程

注意：修改ip地址

eclipse中export server.jar,启动main类选择Server

命令行中运行java -jar server.jar。

运行client连接server。

 

 

 

 

评论

1 楼 yan.dev 2011-03-22  

Server.java 中
1.
Naming.bind("//localhost:"+port+"/hello", hello);
可以改为
Naming.rebind("rmi://localhost:"+port+"/hello", hello);
或
Naming.rebind("//localhost:"+port+"/hello", hello);
2.
如果没有
LocateRegistry.createRegistry(port);
那么需要在类目录下运行,如（.../bin/）
  rmiregistry 1234
此时最好用rebind,否则多次运行server会提示已经banding对象异常