A Pub/Sub-Based Mechanism for Inter-Component Exception Notification in Android Applications

Android developers can use both Java and Kotlin programming languages to create their own apps. Such programming languages provide exception handling facilities to improve apps’ robustness (providing means to implement fault-tolerant measures) and maintainability (separating the error-handling code from the regular one). The Android architecture imposes complexity on the way apps handle exceptions, once exceptions may be raised in parts that are not responsible for handling this abnormal situation. A straightforward solution is to send the Exception Notification (EN) to its concerned handler. However, the way developers are using Android’s inter-component communication mechanism to perform EN may lead to well-known exception handling drawbacks related to the usage of error/return code (e.g., decaying of code readability, programmability, and extensibility). To overcome this problem, we propose a pub/sub-based mechanism to perform EN between Android components called R-EventBus. We evaluate R-EventBus through a performance benchmark and by refactoring a set of apps from the F-Droid repository and comparing the original and refactored versions regarding behavior preservation and EN concern diffusion. Our results indicate that R-EventBus shows negligible performance issues, preserves the apps’ behavior, and considerably improves the modularization of EN concern in the refactored apps.