Characterizing the Usage, Evolution and Impact of Java Annotations in Practice

• Published in: IEEE transactions on software engineering Vol. 47; no. 5; pp. 969 - 986
• Main Authors: Yu, Zhongxing, Bai, Chenggang, Seinturier, Lionel, Monperrus, Martin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2021; IEEE Computer Society; Institute of Electrical and Electronics Engineers
• Subjects: Annotation; Annotations; Computer Science; empirical study; Evolution; Java; Libraries; Open source software; Programming Languages; Runtime; Software Engineering; software evolution; Source code; statistical modelling; Software Evolution; Empirical Study; Statistical Modelling; Annotation
• ISSN: 0098-5589; 1939-3520; 1939-3520
• DOI: 10.1109/TSE.2019.2910516

Annotations have been formally introduced into Java since Java 5. Since then, annotations have been widely used by the Java community for different purposes, such as compiler guidance and runtime processing. Despite the ever-growing use, there is still limited empirical knowledge about the actual usage of annotations in practice, the changes made to annotations during software evolution, and the potential impact of annotations on code quality. To fill this gap, we perform the first large-scale empirical study about Java annotations on 1,094 notable open-source projects hosted on GitHub. Our study systematically investigates annotation usage, annotation evolution, and annotation impact, and generates 10 novel and important findings. We also present the implications of our findings, which shed light for developers, researchers, tool builders, and language or library designers in order to improve all facets of Java annotation engineering.