運行codebase相關的Java RMI代碼時遇到了如下錯誤。
運行參數：
java \
-Djava.security.policy=jndi.policy \
-Djava.naming.provider.url=rmi://$ip:1099 \
-Djava.naming.factory.initial=com.sun.jndi.rmi.registry.RegistryContextFactory \
com.basics.RMI.DynamicCodeDownloading.MethodInterfaceServer
錯誤log：
Exception in thread "main" javax.naming.CommunicationException [Root exception is java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: com.basics.RMI.DynamicCodeDownloading.MethodInterface]
at com.sun.jndi.rmi.registry.RegistryContext.rebind(RegistryContext.java:177)
at com.sun.jndi.rmi.registry.RegistryContext.rebind(RegistryContext.java:182)
at javax.naming.InitialContext.rebind(InitialContext.java:433)
at com.basics.RMI.DynamicCodeDownloading.MethodInterfaceServer.main(MethodInterfaceServer.java:36)
Caused by: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: com.basics.RMI.DynamicCodeDownloading.MethodInterface
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:389)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:283)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:260)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:375)
at sun.rmi.registry.RegistryImpl_Stub.rebind(RegistryImpl_Stub.java:155)
at com.sun.jndi.rmi.registry.RegistryContext.rebind(RegistryContext.java:175)
... 3 more
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: com.basics.RMI.DynamicCodeDownloading.MethodInterface
at sun.rmi.registry.RegistryImpl_Skel.dispatch(RegistryImpl_Skel.java:137)
at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:468)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:300)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: com.basics.RMI.DynamicCodeDownloading.MethodInterface
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.rmi.server.LoaderHandler$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:348)
at sun.rmi.server.LoaderHandler.loadClassForName(LoaderHandler.java:1221)
at sun.rmi.server.LoaderHandler.loadProxyInterfaces(LoaderHandler.java:731)
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:646)
at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:311)
at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:265)
at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1800)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1748)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2042)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:431)
at sun.rmi.registry.RegistryImpl_Skel.dispatch(RegistryImpl_Skel.java:135)
... 14 more
解決辦法：
rmiresigtry 1099 的運行目錄應該在 命令運行的目錄。此時，RMI Registry可以找到當前目錄下的class。
This one works because it puts the required class on the Registry's CLASSPATH, but only if that class isn't in a package. If it was, it wouldn't work.
參考：