Emmanuel Lecharny schrieb: > On 6/5/10 12:18 PM, Felix Knecht wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> On 06/05/10 12:02, Emmanuel Lecharny wrote: >> >>> On 6/5/10 11:57 AM, Felix Knecht wrote: >>> >>>> -----BEGIN PGP SIGNED MESSAGE----- >>>> Hash: SHA1 >>>> >>>> The Cursor interface [1] throws almost for each method an >>>> 'Exception'. I >>>> suggest to make this less generic and throw either the (from javadoc) >>>> "UnsupportedOperationException" or in analogy to the Iterator a >>>> "NoSuchElementException" for methods like before,after,last,first, ... >>>> >>>> >>> I saw that while I was propagating the LdapException through the server. >>> >>> IMO, we should define a base CursorException class, and derive some more >>> specific exception like the one you suggest. >>> >> What would be the benefit of the Exception inflation instead of using >> already existing ones where it logically makes sense? >> > The idea is to use the best Exception for each error case. If the > existing exceptions fit, then I think we can avoid defining our own tree > of exceptions. But I doubt we can cover all the cases with those > existing exception. > > > As I'm not a specialist of the Store code, maybe Alex or Stefan can > bring a bit more light on this aspect.
The org.apache.directory.shared.ldap.cursor package already defines three exceptions, all extend "Exception": - InvalidCursorPositionException - InconsistentCursorStateException - CursorClosedException The InvalidCursorPositionException is thrown when calling Cursor.get() but the cursor isn't positioned correctly. An option is to use a NoSuchElementException instead. The InconsistentCursorStateException is never used. The CursorClosedException is thrown when Cursor.close() was called and afterwards another cursor method is called. An option is to use an IllegalStateException instead. Other exceptions are thrown by the underlying data stores if there are problems when getting data from an index table for example. I think most of them are IOExceptions. Here it makes sense to define a custom exception to wrap those guys. The question is (and I think I can remember we already had such a discussion): should we use checked or unchecked exceptions? If we use checked exceptions it makes sense to define a base CursorException and to derive the above mention exceptions from it. If we use unchecked exceptions we should reuse the existing IllegalStateException and NoSuchElementException. wdyt? Kind Regards, Stefan
