Java RMI (Server: TCP Connection Idle/Client: Unmarshalexception (EOFException))

Question

I'm trying to implement Sun Tutorials RMI application that calculates Pi. I'm having some serious problems and I cant find the solution eventhough I've been searching the entire web and several javaskilled people. I'm hoping you can put an end to my frustrations.

The crazy thing is that I can run the application from the cmd on my desktop computer. Trying the exact same thing with the exact same code in the exact same directories on my laptop produces the following errors. The problem occures when I try to connect the client to the server.

I don't believe that the error is due to my policyfile as I can run it on the desktop. It must be elsewhere. Have anyone tried the same and can you give me a hint as to where my problem is, please?

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POLICYFILE SERVER: grant { permission java.security.AllPermissions; permission java.net.SocketPermission"*", "connect, resolve"; };

POLICYFILE CLIENT: grant { permission java.security.AllPermissions; permission java.net.SocketPermission"*", "connect, resolve";

};

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SERVERSIDE ERRORS: Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\STUDENT>cd\

C:>start rmiregistry

C:>java -cp c:\java;c:\java\compute.jar -Djava.rmi.server.codebase=file:/c:/jav a/compute.jar -Djava.rmi.server.hostname=localhost -Djava.security.policy=c:/jav a/servertest.policy engine.ComputeEngine ComputeEngine bound

Exception in thread "RMI TCP Connection(idle)" java.security.AccessControlExcept ion: access denied (java.net.SocketPermission 127.0.0.1:1440 accept,resolve) at java.security.AccessControlContext.checkPermission(Unknown Source) at java.security.AccessController.checkPermission(Unknown Source) at java.lang.SecurityManager.checkPermission(Unknown Source) at java.lang.SecurityManager.checkAccept(Unknown Source) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.checkAcceptPermi ssion(Unknown Source) at sun.rmi.transport.tcp.TCPTransport.checkAcceptPermission(Unknown Sour ce) at sun.rmi.transport.Transport$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Unknown Source) at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Sou rce) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Sour ce) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source ) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source)

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CLIENTSIDE ERRORS: Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\STUDENT>cd\

C:>java -cp c:\java;c:\java\compute.jar -Djava.rmi.server.codebase=file:\C:\jav a\files\ -Djava.security.policy=c:/java/clienttest.policy client.ComputePi local host 45

ComputePi exception: java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is: java.io.EOFException at sun.rmi.transport.StreamRemoteCall.executeCall(Unknown Source) at sun.rmi.server.UnicastRef.invoke(Unknown Source) at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(Unkn own Source) at java.rmi.server.RemoteObjectInvocationHandler.invoke(Unknown Source) at $Proxy0.executeTask(Unknown Source) at client.ComputePi.main(ComputePi.java:18) Caused by: java.io.EOFException at java.io.DataInputStream.readByte(Unknown Source) ... 6 more

C:>

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Thanks in advance Perry

Answer 1

I tried the same and I found that Java simply ignored the policy file, no matter where I put it or what I put into it or which option I used to make the VM pick it up.

In the end, I create my own SecurityManager in the code and did everything manually.

Answer 2

hmmmm... Please ignore my question above. I got it working right after posting this note (obviously).

It seems it was the Policyfiles. btw it was the wrong files I posted here. THe ones I used just now didn´t include the socketpermissions.

However I know for sure that I tried using these files already (maybe in af different encoding). My thought is that the encoding of the policyfile is important for the java compiler to be able to read and understand the file.

Does anyone has an answer to this?