Java RMI无法绑定服务器

Question

I'm working on Java RMI application, and having problem binding a server to the registry. I'm working on eclipse using rmi plugin, and everything worked fine before I had to format my pc. Also, I'm sure the code is ok since it's the one given to me as a solution, so there must be something wrong with my configuration. Here's the code:

public static void main (String[] args){

    try{

         RMIChatServer myObject = new RMIChatServerImpl();

        System.setSecurityManager(new RMISecurityManager());

        Naming.rebind("Hello", myObject);

        System.out.println("Remote object bound to registry");
    }
    catch( Exception e){

        System.out.println("Failed to register object " + e);
        e.printStackTrace();
        System.exit(1);

    }

}

Exceptions it gives:

Failed to register object java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: access to class loader denied
java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: access to class loader denied
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:419)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:267)
    at sun.rmi.transport.Transport$1.run(Transport.java:177)
    at sun.rmi.transport.Transport$1.run(Transport.java:174)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
    at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:273)
    at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:251)
    at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:377)
    at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)
    at java.rmi.Naming.rebind(Naming.java:177)
    at RMIChatServerImpl.main(RMIChatServerImpl.java:175)
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: access to class loader denied
    at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:409)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:267)
    at sun.rmi.transport.Transport$1.run(Transport.java:177)
    at sun.rmi.transport.Transport$1.run(Transport.java:174)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.ClassNotFoundException: access to class loader denied
    at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:447)
    at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:184)
    at java.rmi.server.RMIClassLoader$2.loadClass(RMIClassLoader.java:637)
    at java.rmi.server.RMIClassLoader.loadClass(RMIClassLoader.java:264)
    at sun.rmi.server.MarshalInputStream.resolveClass(MarshalInputStream.java:216)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1593)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1514)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1750)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    ... 13 more
Caused by: java.security.AccessControlException: access denied ("java.io.FilePermission" "\D:\uni\YEAR 3\Enterprise Programming\java\czat solution 2\bin\-" "read")
    at java.security.AccessControlContext.checkPermission(AccessControlContext.java:366)
    at java.security.AccessController.checkPermission(AccessController.java:555)
    at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
    at sun.rmi.server.LoaderHandler$Loader.checkPermissions(LoaderHandler.java:1176)
    at sun.rmi.server.LoaderHandler$Loader.access$000(LoaderHandler.java:1130)
    at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:411)
    ... 22 more

I researched the problem and most say that it's because of codebase settings (I also use security policy), I have tried different settings, and currently using 'compute from classpath' option provided by rmi plugin, which worked before, but fails now :( Please advice!

Answer 1

FWIW

I upgraded from JDK1.6.0_33 to 1.7.0_21 and had the same problem. I found this document and resolved the problem by starting rmiregistry with:

rmiregistry -J-Djava.rmi.server.useCodebaseOnly=false

Answer 2

So, quick summary of the problem and the solution:

If you're running on JDK 7.1/ 6.29 (possible some other version) RMI server will not bind if you set its codebase to the file or directory on your hard disk. The same code works just fine under older version of JDK (tested on 6.24). Thanks for your help!

Answer 3

The underlying problem here is that the RMI Registry is running under a SecurityManager and its .policy file doesn't grant java.io.FilePermission" "\\D:\\uni\\YEAR 3\\Enterprise Programming\\java\\czat solution 2\\bin\\-" "read" .

The clue to that is that this is a ServerException , ie thrown at the target of the call, and that the call itself is rebind() .

See this post for an explanation.

Answer 4

Yes this problem occurs in Java 1.7 and above. So always go through the enhancements document if you upgrade your Java version. It is a fairly simple solution. You just need to start the rmiregistry in a different way.

Go through this document- http://docs.oracle.com/javase/7/docs/technotes/guides/rmi/enhancements-7.html

Answer 5

Have you tried to explicitly give access to the file using the *.policy file? as described on http://docs.oracle.com/javase/7/docs/technotes/guides/security/permissions.html

grant codebase "file:/path/to/code" {
    permission java.io.FilePermission "\D:\uni\YEAR 3\Enterprise Programming\java\czat solution 2\bin\-", "read";
}

I have the same issue with openjdk... probably caused by this commit: http://hg.openjdk.java.net/jdk7u/jdk7u-gate/jdk/rev/7ed2fd310470