FindBugs on a Wicket + Spring application

FindBugs is a great static analysis tool and it helped me to find several bugs but recently we switched to Wicket 1.3 framework for web development and we got few false positives which were related to using Spring with Wicket.


We had Wicket page classes with fields being injected by Spring using the @SpringBean annotation.
FindBugs complained that these fields should have been serializable or transient (SE_BAD_FIELD error) and this seemed an issue as Wicket does use serialization a lot to save pages into its session.
In fact, it turned out to be a false postive because Wicket manages this by using Spring dynamic proxies.

Unitialized fields in constructor

Another FindBugs complaint in Wicket page classes was about de-referencing fields in constructor before having initialize them (UR_UNINIT_READ error).
Again, this turned out to be a false positive because our pages did extend WebPage class that takes care of injecting all SpringBean annotated fields using a PropertyResolver.
Something to remember: the default PropertyResolver is able to initialize private fields and ignores setters.


Using Spring beans in Wicket pages introduces a lot of dynamicity that defeats static analysis when dealing with object initialization and serialization.
FindBugs is so valuable that it is worth excluding these rules on Pages and having a naming convention for these classes makes it easier to do. Our page classes are now named with the "Page" suffix.

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