Remote Method Invocation (RMI) notes for release Alpha2.


- RMI is supported for Java applications and in the AppletViewer.

- RMI requires local installation of the rmi package appropriate for
  Solaris or Win95/NT.

- Any application that exports remote objects must be allowed
  by the SecurityManager to use ServerSockets to listen for and accept
  incoming socket connections. 

- Applets may not export remote objects since the SecurityManager 
  prevents using ServerSocket.  This will be supported in a future
  update.

- The current serialization policy allows private fields of objects to
  be serialized by default.  The final release will require
  that objects declare that they are serializable.

- The core Java classes have received no special treatment of their
  private data. Private data in system classes can be exposed with
  serialization.  These classes will be properly protected before FCS.

- This release differs from the specification in the following ways:

  * Support for cloning of remote server objects is not implemented.

  * The mechanisms to support the java.rmi.server.Unreferenced
    interface are not implemented.

  * Servers ignore the java.rmi.server.ClientClassDisable property and
    will attempt to load client specified classes as long as a
    security manager is present.

- The RMI package will expire on 30 Sep 1996:

- The RMI package is compatible with:

  * JDK 1.0.2 on Solaris
  * JDK 1.0.2 on Win32 and NT


- When compiling rmi based programs with the classpath set to use
  the rmi.zip file, javac may incorectly report an error reguarding
  the importing of java.rmi.*.  The compiler correctly compiles the
  file and writes the output. To avoid the error message, the rmi.zip
  file can be unzip'ed and the classpath set the class directory.
  i.e.
	% mkdir $RMIHOME/classes;
	% cd $RMIHOME/classes
	% unzip $RMIHOME/lib/rmi.zip
	% setenv CLASSPATH $RMIHOME/classes

- Simple RMI clients should use System.exit to terminate,
  currently the RMI runtime threads will keep the VM from exiting.
  This does not apply to Applets.

- Stub classes loaded in an applet do not identify their URL if
  they are passed to a RMI based service.  Instead, the service must
  be configured using the property java.rmi.server.StubClassBase
  with the URL to load classes from.

- The roles of the Remote and RemoteObject have been switched from earlier
  releases, their definitions are:

  * Interface java.rmi.Remote identifies a remote interface.
  * Class java.rmi.server.RemoteObject is the implementation that
    supports the remote objects.  Clients and servers rarely need to
    refer to the RemoteObject class.

- On some network configurations the Registry operations of bind,
  rebind and unbind will throw a AccessException in cases where it
  should not.  The Registry implementation restricts these operations
  to clients on the same host as the Registry.  If the hostname or IP
  address does not match the exception is thrown. In some DHCP and PPP
  network configurations the assigned IP address and hostname do not
  match the name assigned to the node.  A workaround is to statically
  and explicitly assign the IP address for the node.

  On Solaris, another alternative is to change the node name have the
  IP address assigned by PPP, or to set the nodename to "localhost"
  which is bound to the IP address 127.0.0.1.