Identifying Data Transfer Objects in EJB Applications

Data transfer object (DTO) is a design pattern that is commonly used in Enterprise Java applications. Identification of DTOs has a range of uses for program comprehension, optimization, and evolution. We propose a dynamic analysis for identifying DTOs in Enterprise Java applications. The analysis tracks the reads and writes of object fields, and maintains information about the application tier that initiates the field access. The lifecycle of a DTO is represented by a finite state automaton that captures the relevant run-time events and the location of the code that triggers these events. We implemented the proposed approach using the JVMTI infrastructure in Java 6, and performed a study on a real-world Enterprise Java application which is deployed for commercial use. Our results indicate that the dynamic analysis achieves high precision and has acceptable overhead.