javaRMI使用入门程序及配置

　　本例子包含了共5个文件，分别是HelloClient，Hello，HelloServer，Configur，config.properties

--------------------------------------------------------------------------------

/*Hello.Java*/
/*
* Created on 2004-11-10
*
*/
package test.rmi;

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

/**
* @author dogcome
*
* <p>远程方法调用接口，定义远程调用方法</p>
*/
public interface Hello extends Remote {

String sayHello() throws RemoteException;

}

--------------------------------------------------------------------------------

/*HelloServer*/
/*
* Created on 2004-11-10
*
*/
package test.rmi;

import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;

/**
* @author dogcome
*
*<p>服务器端，实现了Hello接口中的方法，用于实现远程调用方法的具体业务逻辑</p>
*/
public class HelloServer extends UnicastRemoteObject implements Hello {
String name;
public HelloServer(String s) throws RemoteException {
super();
name=s;
}

public String sayHello() throws RemoteException {
// TODO Auto-generated method stub
return "Hello world!";
}

public static void main(String[] args) {
/**下面这句话若要加上，则需要进行权限的认证，即增加.policy文件
* 并且在命令行中使用如下格式
* java -Djava.security.policy=java.policy test.rmi.HelloServer
*/
/*System.setSecurityManager(new RMISecurityManager());*/
Registry registry = null;
try {
/**启动注册服务器，使用了这个语句就不再需要在命令行环境中
*启动registry服务了
*/
registry = LocateRegistry.getRegistry();
/* 若没有获得连接，则此句会抛出异常，后面在捕捉后进行相关处理 */
registry.list();
System.out.println("Register the exist server!"); //$NON-NLS-1$
} catch (RemoteException re) {
try {
int port = Integer.parseInt(Configur
.getString("HelloServer.RegistryServerPort")); //$NON-NLS-1$
registry = LocateRegistry.createRegistry(port);
System.out.println("Create Registry Server!"); //$NON-NLS-1$
} catch (Exception e) {
e.printStackTrace();