Improving developers awareness of the exception handling policy

The exception handling policy of a system comprises the set of design rules that specify its exception handling behavior (how exceptions should be handled and thrown in a system). Such policy is usually undocumented and implicitly defined by the system architect. Developers are usually unaware of such rules and may think that by just sprinkling the code with catch-blocks they can adequately deal with the exceptional conditions of a system. As a consequence, the exception handling code once designed to make the program more reliable may become a source of faults (e.g., the uncaught exceptions are one of the main causes of crashes in current Java applications). To mitigate such problem, we propose Exception Policy Expert (EPE), a tool embedded in Eclipse IDE that warns developers about policy violations related to the code being edited. A case study performed in a real development context showed that the tool could indeed make the exception handling policy explicit to the developers during development.