创建第一个RMI应用

       学习使用RMI框架，抄写了一段例子代码：

     代码如下：

package com.you.rmi; import java.rmi.Remote; import java.rmi.RemoteException; import java.rmi.registry.LocateRegistry; import java.rmi.server.UnicastRemoteObject; import java.util.Date; import javax.naming.Context; import javax.naming.InitialContext; public class SimpleServer { public static void main(String[] args) { try { HelloService service1 = new HelloServiceImpl("service1"); HelloService service2 = new HelloServiceImpl("service2"); Context namingContext = new InitialContext(); LocateRegistry.createRegistry(1099); namingContext.rebind("rmi://localhost:1099/HelloService1", service1);//rebind注册对象，把对象与一个名字 namingContext.rebind("rmi://localhost:1099/HelloService2", service2);//绑定，如果改名字已经被绑定，不过抛出异常 System.out.println("服务器注册了两个HelloService对象"); } catch (Exception e) { e.printStackTrace(); } } } interface HelloService extends Remote{ public String echo(String msg) throws RemoteException; public Date getTime() throws RemoteException; } class HelloServiceImpl extends UnicastRemoteObject implements HelloService{ /** * */ private static final long serialVersionUID = 1L; private String name; public HelloServiceImpl(String name) throws RemoteException{ this.name = name; } @Override public String echo(String msg) { System.out.println(name + "调用echo()方法"); return "echo:" + msg + "from" + name; } @Override public Date getTime() { System.out.println(name + "调用getTime（）方法"); return new Date(); } }
package com.you.rmi; import java.rmi.RemoteException; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NameClassPair; import javax.naming.NamingEnumeration; import javax.naming.NamingException; 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()); } public static void main(String[] args) { try { String url = "rmi://localhost/"; Context namingContext = new InitialContext(); //获得远程对象的存根对象 HelloService service1 = (HelloService) namingContext.lookup(url + "HelloService1"); HelloService service2 = (HelloService) namingContext.lookup(url + "HelloService2"); //测试存根对象所属的类 Class stubClass = service1.getClass(); System.out.println("service1 是" + stubClass.getName() + "的实例"); Class[] interfaces = stubClass.getInterfaces(); for(int i = 0; i < interfaces.length; i++) { System.out.println("存根类实现了" + interfaces[i].getName()); System.out.println(service1.echo("hello")); System.out.println(service1.getTime()); System.out.println(service2.echo("hello")); System.out.println(service2.getTime()); showRemoteObjects(namingContext); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
在例子中没有LocateRegistry.createRegistry(1099);这句代码，一开始运行的时候，总是报错，报服务器拒绝连接的错误，加上这句话就运行成功了，虽然rmi的默认端口是1099，但是需要告诉服务器一声，不然服务器不会得到通知，拒绝连接。