Java Enterprise Best Practices

Don’t Throw RemoteException in Your Server Code

The javadocs for RemoteException say the following:

A RemoteException is the common superclass for a number of communication-related exceptions that may occur during the execution of a remote method call. Each method of a remote interface, an interface that extends java.rmi.Remote, must list RemoteException in its throws clause.

This might make it seem like it’s OK, and maybe even a good thing, for your server-side code to throw instances of RemoteException. It’s certainly easy, if you’re working on a server and discover a new exceptional condition, to add a line of code such as the following:

throw new RemoteException("You can't deposit a negative amount of money");

It might even seem like good programming practice—after all, the client code already catches RemoteException. But it’s a very bad idea to use RemoteException in this way.

To understand why, you need to understand what RemoteException really means. The real meaning of RemoteException is that something has gone wrong between your client code and server code. That is, your client made a method call on a stub. Your server code is expecting to receive a method invocation via its skeleton. If something goes wrong between that call to the stub and the resulting invocation made by the skeleton, it will be signalled by an instance of RemoteException. Exceptions that happen within the server should be signalled by instances of some other exception class that doesn’t extend RemoteException ...