Philip Ogren wrote:
In the tutorial there is a section titled "Retaining references to
JCas objects between calls to process()" which tells you not to retain
references to JCas objects.
JCas objects (as well as non-JCas Java cover objects you get using the
non-JCas methods) are tiny objects that refer to data in an associated
CAS. If that CAS still has the data, you can retain these references.
If the CAS is reset, and then perhaps refilled subsequently with other
data, these old references could still point into the CAS, but what
they'd be pointing to would be meaningless.
This is why this advice is given.
If for instance, you do your own custom application which loads and
calls a series of annotators, passing a common CAS among them, it's fine
to hold onto JCas (or non-JCas Java) references you might have in the
application, over the set of process() calls. Just be sure to not use
the references, once you've reset the CAS.
I hope this clarifies things a bit.
-Marshall
