Java Enterprise Best Practices

Name

NoSuchObjectException

Where thrown

In the RMI infrastructure on the server side.

When thrown

As part of the standard distributed communication between client and server. This is thrown after the RMI infrastructure on the server has already demarshalled the arguments and is trying to actually call a method on your code.

Why thrown

Every remote method call contains an ObjID, which uniquely identifies the object on which the method call is being made. The RMI infrastructure maintains a hashtable of instances of ObjID to RemoteServers. This error indicates that the ObjID passed over the wire was not a key in this table.

What it means

This usually occurs when a client has a stub to a server that no longer is running in the server process. This is a strange exception to encounter because stubs try to maintain leases on servers (which usually prevents a server from being shut down). As such, this exception usually indicates a failure in the distributed garbage collector (it doesn’t indicate that the server process crashed; if the server process crashed, an instance of ConnectException would have been thrown instead).