RMI，ServerException: RemoteException

Question

我遵循了这个教程：http://download.oracle.com/javase/1.5.0/docs/guide/rmi/hello/hello-world.html#2并创建了3个简单的文件(接口Hello.java、类Server.java和Client.java)。不幸的是，当我尝试像这样运行服务器时：

start java -classpath "D:\[...]\RMISample\src" example.hello.Server

我得到了以下例外：

    Server exception: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: example.hello.Hello
java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: example.hello.Hello
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:396)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:250)
    at sun.rmi.transport.Transport$1.run(Transport.java:159)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
    at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(Unknown Source)
    at sun.rmi.transport.StreamRemoteCall.executeCall(Unknown Source)
    at sun.rmi.server.UnicastRef.invoke(Unknown Source)
    at sun.rmi.registry.RegistryImpl_Stub.bind(Unknown Source)
    at example.hello.Server.main(Server.java:26)
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: example.hello.Hello
    at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:386)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:250)
    at sun.rmi.transport.Transport$1.run(Transport.java:159)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: example.hello.Hello
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:247)
    at sun.rmi.server.LoaderHandler.loadProxyInterfaces(LoaderHandler.java:711)
    at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:655)
    at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:592)
    at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:628)
    at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:294)
    at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:238)
    at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1530)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1492)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1731)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350)
    ... 12 more

会出什么问题呢？问候

Answer 1

当您启动服务器应用程序时，您必须指出RMI应该在何处查找类，您可以使用java.rmi.server.codebase属性来执行此操作，因此正确的命令如下所示：

java -classpath "D:\[...]\bin" 
-Djava.rmi.server.codebase=file:/D:\[...]\bin/ example.hello.Server