Validating structural properties of nested objects

Abstract

Frameworks are widely used to facilitate software reuse and accelerate development time. However, there are currently no systematic mechanisms to enforce the explicit and implicit rules of these frameworks. This paper focuses on a class of framework rules that place restrictions on the properties of data structures in framework applications. We present a mechanism to enforce these rules by the use of a generic "bad store template" which can be customized for different rule instances. We demonstrate the use of this template to validate specific bad store rules within J2EE framework applications. Violations of these rules cause subtle defects which manifest themselves at runtime as data loss, data corruption, or race conditions. Our algorithm to detect "bad stores" is implemented in the Smart Analysis-Based Error Reduction (SABER) validation tool, where we pay special attention to facilitating problem understanding and remediation, by providing detailed problem explanations. We present experimental results on four commercially deployed e-commerce applications that show over 200 "bad stores".