The RMI runtime implementation will now preserve the server-side stack trace information of an exception that is thrown from a remote call, in addition to filling in the client-side stack trace as it did previous releases. Therefore, when such an exception becomes accessible to client code, its stack trace will now contain all of its original server-side trace data followed by the client-side trace.
In J2SE 1.4.0, certain static methods of java.rmi.server.RMIClassLoader delegate their behavior to an instance of a new service provider interface, java.rmi.server.RMIClassLoaderSpi. This service provider object can be configured to augment RMI's dynamic class-loading behavior for a given application. By default, the service provider implements the standard behavior of all of the static methods in RMIClassLoader.
The java.rmi.server.hostname property can now be dynamically updated to indicate that future exports should use a new host name. Therefore, the new host name value will be contained in the stub for an object that is exported after the property is updated.
For more information, see http://java.sun.com/j2se/1.4/docs/guide/rmi/relnotes.html.