Listings 1.3 and 1.4 gives the definition of the IBookkeepingInfo and IBookkeepingEditor interfaces in Java. Some functions are returning a Handle that encapsulates the actual return value. The return value is either a single object (see type definitions in section 1) or a java.util.Vector object containing such objects.
Note that the two files methods should never be used except for debug purposes. As a matter of fact, the first one would output the full list of available files, which would kill the server for lack of memory on the production system. The second method would execute any SQL query which would allow a user to delete or corrupt data.
The methods are only there for internal debug purposes and should never be exposed to the end user.