这是代码:
界面“通讯”
package itu.exercies.RMI.server; import java.rmi.Remote; import java.rmi.RemoteException; public interface ICommunication extends Remote { public String doCommunicate(String name) throws RemoteException; }
界面实现“CommunicationImpl”:
package itu.exercies.RMI.server; import java.rmi.RemoteException; import java.rmi.server.UnicastRemoteObject; public class CommunicationImpl extends UnicastRemoteObject implements ICommunication { /** * */ private static final long serialVersionUID = 1L; public CommunicationImpl() throws RemoteException { super(); } @Override public String doCommunicate(String name) throws RemoteException { return "Hello this is server,whats up " +name+ " ?!\n"; } }
这是我的主要服务器类“CommunicationServer”:
package itu.exercies.RMI.server; import java.net.MalformedURLException; import java.rmi.Naming; import java.rmi.RemoteException; public class CommunicationServer { /** * @param args * @throws RemoteException * @throws MalformedURLException */ public static void main(String[] args) throws RemoteException,MalformedURLException { CommunicationImpl imp = new CommunicationImpl(); Naming.rebind("CommunicationImpl",imp); System.out.println("Server started..."); System.out.println("Object successfully registered. It is bound to the name 'CommunicationImpl'."); } }
这是我的客户端“CommunicationClient”:
package itu.exercies.RMI.client; import java.net.MalformedURLException; import java.rmi.Naming; import java.rmi.NotBoundException; import java.rmi.RemoteException; import itu.exercies.RMI.server.CommunicationImpl; public class CommunicationClient { public static void main(String[] args) throws MalformedURLException,RemoteException,NotBoundException { String url = new String("rmi://localhost/CommunicationImpl"); CommunicationImpl comm = (CommunicationImpl)Naming.lookup(url); String reply = comm.doCommunicate("Wiktor"); System.out.println(reply); } }
现在我试图运行它:
>我使用终端导航到我的项目的bin目录
我从那里经营rmiregistry
>我从新的终端窗口运行我的CommunicationServer(它打印出的消息,使其似乎工作)
>我打开第三个终端窗口,当我尝试运行我的CommunicationClient时,它会抛出异常.
java itu.exercies.RMI.client.CommunicationClientException in thread “main” java.lang.ClassCastException: $Proxy0 cannot be cast to itu.exercies.RMI.server.CommunicationImpl
at itu.exercies.RMI.client.CommunicationClient.main(CommunicationClient.java:14)
到目前为止,我试图通过使用rmic创建一个“CommunicationImpl”对象的存根来修复它,但现在而不是’$Proxy0′,错误是指’CommunicationImpl_Stub’:
Exception in thread “main” java.lang.ClassCastException: itu.exercies.RMI.server.CommunicationImpl_Stub cannot be cast to itu.exercies.RMI.server.CommunicationImpl
at itu.exercies.RMI.client.CommunicationClient.main(CommunicationClient.java:14)
在这一点上,我不知道要查找错误.有人可以给我任何建议吗?
解决方法
CommunicationImpl comm = (CommunicationImpl) Naming.lookup(url);
同
ICommunication comm = (ICommunication) Naming.lookup(url);
CommunicationImpl是ICommunication的服务器实现.客户端既不知道也不关心实现,只有接口.