运行rmi服务器，classnotfound [英] running rmi server, classnotfound

问题描述

我正在尝试运行一个将类绑定到命名服务器的java应用程序，但是我经常得到一个ClassNotFoundException

首先我启动注册表： / p>

rmiregistry

然后从eclipse我尝试执行服务器但是得到这个错误

java.rmi.ServerException：在服务器线程中发生RemoteException;嵌套异常是：
java.rmi.UnmarshalException：error unmarshalling arguments;嵌套异常是：
java.lang.ClassNotFoundException：progInternet2008.commons.NominabileFactory
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）
在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）
在java。 util.concurrent.ThreadPoolExecutor $ Worker.runTask（ThreadPoolExecutor.java:886）
在java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:908）
在java.lang.Thread。运行（Threa d.java:619）
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer（StreamRemoteCall.java:255）
at sun.rmi.transport.StreamRemoteCall.executeCall（StreamRemoteCall.java:233）
at sun.rmi.server.UnicastRef.invoke（UnicastRef.java:359）
at sun.rmi.registry.RegistryImpl_Stub.rebind（Unknown Source）
at progInternet2008.Pozzobon.tesi.Slave。 main（Slave.java:54）
导致：java.rmi.UnmarshalException：error unmarshalling arguments;嵌套异常是：
java.lang.ClassNotFoundException：progInternet2008.commons.NominabileFactory
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）
在java.util.concurrent.ThreadPoolExecutor $ Worker.runTask（ThreadPoolExecutor.java:886）
在java.util.concurrent.ThreadPoolExecutor $ Worker .run（ThreadPoolExecutor.java:908）
在java.lang.Thread.run（Thread.java:619）
引起的：java.lang.ClassNotFoundException：progInternet2008.commons.NominabileFactory
在java.net.URLClassLoader $ 1.run（URLClassLoader.java:200）
在java.security.AccessController.doPrivileged（本机方法）
在java.net.URLClassLoader.findClass（URLClassLoader.java:188 ）
在java.lang.ClassLoader.loadClass（ClassLoader.java:307）
在java.lang.ClassLoader.loadClass（ClassLoader.java:252）
在java.lang.ClassLoader。 loadClassInternal（ClassLoader.java:320）
java.lang.Class.forName0（Native Method）
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）
在java.rmi.server.RMI ClassLoader $ 2.loadProxyClass（RMIClassLoader.java:628）
在java.rmi.server.RMIClassLoader.loadProxyClass（RMIClassLoader.java:294）
at sun.rmi.server.MarshalInputStream.resolveProxyClass（MarshalInputStream.java ：238）
在java.io.ObjectInputStream.readProxyDesc（ObjectInputStream.java:1531）
在java.io.ObjectInputStream.readClassDesc（ObjectInputStream.java:1493）
在java.io. ObjectInputStream.readOrdinaryObject（ObjectInputStream.java:1732）
在java.io.ObjectInputStream.readObject0（ObjectInputStream.java:1329）
在java.io.ObjectInputStream.readObject（ObjectInputStream.java:351）
... 12更多

我已经阅读了RMI Java教程，但仍然无法使其正常工作...

作为VM参数我设置了这个：

-Djava.rmi.server .codebase = file：$ {workspace_loc} / progInternet2008

请帮助我

（我使用Java 6）

解决方案

异常发生是因为rmiregistry应用程序不知道从中加载类。当您尝试绑定RMI注册表中的对象时，注册表会下载该对象的类定义。其他一些答案告诉你通过设置rmiregistry应用程序的类路径来解决这个问题，以便它在启动时具有类定义，并且不需要下载任何东西，但Sun的Java RMI教程 明确地说这样做 。我怀疑这有可能导致注册表中的类的版本与服务器上的类之间的冲突。

正确的处理问题的方法是设置您尝试执行的java.rmi.server.codebase属性。该属性要求使用正斜杠终止目录路径，如下所示：

 
 -Djava.rmi.server.codebase = file： $ {workspace_loc} / progInternet2008 / 
 

如果$ {workspace_loc}变量是相对路径和rmiregistry应用程序，您可能还会遇到问题没有在同一目录中启动，所以相对路径不正确。如果您使路径绝对，或者在适当的目录中启动rmiregistry，则ClassNotFoundException应该消失。请参阅。

Hi I'm trying to run a java application that binds a class to the naming server, but i constantly get a ClassNotFoundException

First I start the registry:

rmiregistry

then from eclipse I try to execute the server but get this error

java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: java.lang.ClassNotFoundException: progInternet2008.commons.NominabileFactory 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:619) at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359) at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source) at progInternet2008.Pozzobon.tesi.Slave.main(Slave.java:54) Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: java.lang.ClassNotFoundException: progInternet2008.commons.NominabileFactory 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:619) Caused by: java.lang.ClassNotFoundException: progInternet2008.commons.NominabileFactory at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) 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:1531) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1493) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351) ... 12 more

I've read the RMI Java tutorial but still could not get it working...

As VM Arguments I've set this:

-Djava.rmi.server.codebase=file:${workspace_loc}/progInternet2008

please help me

(I'm using Java 6)

解决方案

The exception is occurring because the rmiregistry application doesn't know where to load classes from. When you attempt to bind an object in the RMI registry, the registry downloads the class definition for that object. Some of the other answers are telling you to get around this by setting the classpath for the rmiregistry app so that it has the class definitions when it is started and doesn't need to download anything, but Sun's Java RMI tutorial explicitly says not to do this. I suspect this has the potential to cause conflicts between the version of the class in the registry and the class on the server.

The correct way to handle the problem is to set the java.rmi.server.codebase property as you were trying to do. The property requires that a directory path be terminated with a forward slash, like so:

-Djava.rmi.server.codebase=file:${workspace_loc}/progInternet2008/

You may also be having trouble if the ${workspace_loc} variable is a relative path and the rmiregistry application was not started in the same directory so the relative path is not correct for it. If you either make the path absolute, or start the rmiregistry in the appropriate directory, the ClassNotFoundException should go away. See the tutorial on the java.rmi.server.codebase property for a little more detailed information.

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