Question

我是java RMI的新手，并且正在尝试运行示例java rmi程序。但我得到了java.rmi.notboundexception。以下是我的代码。

服务器代码

server.java 

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

public class Server implements Hello {

public Server() {}

public String sayHello() {
return "Hello, world!";
}

public static void main(String args[]) {
Hello stub = null;
Registry registry = null;

try {
    Server obj = new Server();
    stub = (Hello) UnicastRemoteObject.exportObject(obj, 0);
    registry = LocateRegistry.getRegistry();
    registry.bind("Hello", stub);

    System.err.println("Server ready");
} catch (Exception e) {
    System.err.println("Server exception: " + e.toString());
    e.printStackTrace();

/*  Rewritten as per EJP's remarks 
    try{
// Line 66 , where the error is pointing 
    registry.unbind("Hello");
    registry.bind("Hello",stub);
        System.err.println("Server ready");
    }catch(Exception ee){
    System.err.println("Server exception: " + ee.toString());
        ee.printStackTrace();
    }
}
*/ 


}
}

客户端代码 client.java

import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class Client {

private Client() {}

public static void main(String[] args) {

String host = (args.length < 1) ? null : args[0];
try {
    Registry registry = LocateRegistry.getRegistry(host);
    Hello stub = (Hello) registry.lookup("Hello");
    String response = stub.sayHello();
    System.out.println("response: " + response);
} catch (Exception e) {
    System.err.println("Client exception: " + e.toString());
    e.printStackTrace();
}
}
}

接口代码

Hello.java

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

public interface Hello extends Remote {
    String sayHello() throws RemoteException;
}

遵循的步骤

javac Server.java
javac Client.java
使用以下命令启动Java RMI注册表

启动rmiregistry

在这些之后，当我使用java server命令运行服务器时，我遇到了异常。在实施EJP提到的更改后，异常从原始帖子发生了变化。

C:\Users\hp\Desktop\NUS Modules\Distributed systems\Assignment1\HelloWorld\Hello
World\Server>java Server
Server exception: java.rmi.ServerException: RemoteException occurred in server t
hread; nested exception is:
    java.rmi.UnmarshalException: error unmarshalling arguments; nested excep
tion is:
    java.lang.ClassNotFoundException: Hello
java.rmi.ServerException: RemoteException occurred in server thread; nested exce
ption is:
    java.rmi.UnmarshalException: error unmarshalling arguments; nested excep
tion is:
    java.lang.ClassNotFoundException: Hello
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:420
)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:268)
    at sun.rmi.transport.Transport$1.run(Transport.java:178)
    at sun.rmi.transport.Transport$1.run(Transport.java:175)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:174)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:5
57)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTranspor
t.java:812)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport
.java:671)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.
java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:617)
    at java.lang.Thread.run(Thread.java:745)
    at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(Stream
RemoteCall.java:276)
    at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:
253)
    at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:379)
    at sun.rmi.registry.RegistryImpl_Stub.bind(Unknown Source)
    at Server.main(Server.java:61)
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested ex
ception is:
    java.lang.ClassNotFoundException: Hello
    at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:410
)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:268)
    at sun.rmi.transport.Transport$1.run(Transport.java:178)
    at sun.rmi.transport.Transport$1.run(Transport.java:175)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:174)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:5
57)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTranspor
t.java:812)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport
.java:671)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.
java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: Hello
    at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.rmi.server.LoaderHandler$Loader.loadClass(LoaderHandler.java:1207
)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:340)
    at sun.rmi.server.LoaderHandler.loadClassForName(LoaderHandler.java:1221 
)
    at sun.rmi.server.LoaderHandler.loadProxyInterfaces(LoaderHandler.java:7
31)
    at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:674)
    at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:611)
    at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:6
46)
    at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:311
)
    at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStrea
m.java:255)
    at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1559)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1515)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1
774)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:371)
    ... 13 more

请帮助解决此错误。代码中的任何错误或任何防火墙设置都需要完成。

java版 - 1.8 操作系统 - Windows 7

Answer 1

你试图解开那些不存在的东西。摆脱unbind（）调用并将以下bind（）调用更改为rebind（）。

但我没有看到在异常处理程序中执行任何操作的重点。相反，你应该打印实际的异常，看看它是什么，首先。

尝试运行简单的java rmi时获取ClassNotFoundException

1 个答案: