Bitter connections and coupling - Bitter Java - page 204

Split Cleaners
D ESCRIPTION : When a resource is allocated separately from where it is
freed, cleanup can be lost.
M OST FREQUENT SCALE : Application.
R EFACTORED SOLUTION NAME : Pairing Connections with Cleanup.
R EFACTORED SOLUTION TYPE : Software.
R EFACTORED SOLUTION DESCRIPTION : Connections should be allocated
and cleared in close proximity, and finally blocks should be used for con-
nection cleanup. In this way, inspection will quickly show whether a con-
nection has been cleansed appropriately.
R OOT CAUSES : Haste, sloth.
A NECDOTAL EVIDENCE : “That connection probably gets cleaned up
somewhere else.”
S YMPTOMS , CONSEQUENCES : Resources, like database or file connections,
run out prematurely.
Hardwired Connections
D ESCRIPTION : For business-to-business connections, a common imple-
mentation is to enumerate all of the fields in an entire interface, complete
with parameter and return types. The connection is then made through
some form of a remote procedure call. This approach makes the connec-
tion difficult to maintain and support as the interfaces change.
M OST FREQUENT SCALE : Enterprise.
R EFACTORED SOLUTION NAME : Web services or XML messages.
R EFACTORED SOLUTION TYPE : Software.
R EFACTORED SOLUTION DESCRIPTION : Connections should be made
with common standards that allow a dynamic description of the transac-
tion, including the parameter set and the message construction. Web ser-
vices provide such a wrapping, through open standards, including SOAP
for messaging and XML for the description of the parameter and message
format.
T YPICAL CAUSES : The solution described by this antipattern is actually
one of the most common implementations of business-to-business con-
nections. Many have not yet migrated to XML -based solutions for a variety
of reasons.