Trends on empty exception handlers for Java open source libraries

Exception-handling structures provide a means to recover from unexpected or undesired flows that occur during software execution, allowing the developer to put the program in a valid state. Still, the application of proper exception-handling strategies is at the bottom of priorities for a great number of developers. Studies have already discussed this subject pinpointing that, frequently, the implementation of exception-handling mechanisms is enforced by compilers. As a consequence, several anti-patterns about Exception-handling are already identified in literature. In this study, we have picked several releases from different Java programs and we investigated one of the most well-known anti-patterns: the empty catch handlers. We have analysed how the empty handlers evolved through several releases of a software product. We have observed some common approaches in terms of empty catches' evolution. For instance, often an empty catch is transformed into a empty catch with a comment. Moreover, for the majority of the programs, the percentage of empty handlers has decreased when comparing the first and last releases. Future work includes the automation of the analysis allowing the inclusion of data collected from other software artefacts: test suites and data from issue tracking systems.