Java RMI HelloWorld

Java RMI HelloWorld

 

RMI 远程方法调用. 顾名思义就是可以像调用本地程序方法一样调用远程(其他JVM)的程序方法.

 

分为3个部分:

Stub:中介,代理. 封装了远程对象的调用,客户端需要通过stub与server交流

RemoteServer,:远端服务提供者.也就是RemoteObject

Client:客户端

 

代码示意:

 

RemoteObject, 远程服务提供者, 我写了一个main方法,在本地6600端口启动这个服务,

想要启动服务,只要run即可

package demo2;   import java.rmi.Naming; import java.rmi.RemoteException; import java.rmi.registry.LocateRegistry; import java.rmi.server.UnicastRemoteObject;   public class RemoteEchoServer extends UnicastRemoteObject implements RemoteEcho {       protected RemoteEchoServer() throws RemoteException {         super();     }       @Override     public Object echo(Object object) throws RemoteException {         return object;     }       public static void main(String[] args) throws Exception {         RemoteEchoServer server = new RemoteEchoServer();         LocateRegistry.createRegistry(6600);         Naming.rebind("rmi://127.0.0.1:6600/RemoteEchoServer", server);     }   }

 

 

Stub,代理,与RemoteObject交流均需要通过它

 

package demo2;   import java.rmi.Remote; import java.rmi.RemoteException;   public interface RemoteEcho extends Remote {     Object echo(Object object) throws RemoteException; }

 

对Stub的进一步封装,即如何得到Stub对象

package demo2;   import java.rmi.Naming;   public class RemoteEchoFactory {       public static RemoteEcho getEcho() throws Exception {         return (RemoteEcho) Naming.lookup("rmi://127.0.0.1:6600/RemoteEchoServer");     } }

 

 

下面就是Client, server启动后,就能正常跑下面这个程序

package demo2;   public class RemoteEchoClient {     public static void main(String[] args) throws Exception {         long start = System.currentTimeMillis();         RemoteEcho echo = RemoteEchoFactory.getEcho();         System.out.println(echo.echo("kiss u"));         System.out.println(System.currentTimeMillis()-start);     } }

 

Client 通过本地的Factory得到封装好的Stub, 他指向了RemoteObject, 然后就可以像调用本地方法一样直接用.