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

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?

---

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";

};
______________________________________________

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$1.run(Unknown Source)
        at java.开发者_开发百科security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Unknown Source)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
        at sun.rmi.transport.tcp.TCPTransport$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)

_______________________________
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:\>

---

Thanks in advance Perry

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Your server didn't have permission to accept a connection from that client.

Ergo your policy file wasn't where you said it was, or wasn't loaded for some other reason.

Run it with -Djava.security.debug=access,failure and you will see what protection domain you were in when the security exception occurred, and what permissions it had.

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

NB a file: codebase cannot work if it refers to a local filesystem, unless the client is also in the same machine, which makes RMI fairly pointless. Codebase URLs need to refer to locations that are accessible by the client. You can use shared file systems but you must provide a URL that is usable by the client. The server doesn't use its own codebase URL at all.

---

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.