Fixrleak: Fixing Java Resource Leaks with GenAI

Summary

Introduction Resource leaks, where resources like files, database connections, or streams aren’t properly released after use, are a persistent issue in Java applications. These leaks can lead to performance degradation, and system failures. While tools like SonarSource SonarQube™ effectively identify such leaks, the fixing process remains manual, time-consuming, and prone to errors. To address this, we developed FixrLeak, a generative AI-based framework that automates the detection and repair of resource leaks. FixrLeak combines Abstract Syntax Tree (AST) analysis with generative AI (GenAI) to produce accurate, idiomatic fixes while following Java best practices like try-with-resources. Deployed within Uber’s extensive Java codebase, FixrLeak significantly reduces manual effort, improves developer productivity, and improves code quality, showcasing the transformative potential of AI-driven solutions in large-scale software engineering. Background Understanding Resource Leaks in Java Resource leaks occur when a program fails to properly release resources such as files, database connections, or streams after use. These leaks can lead to serious issues, including performance degradation, application failures, and an inability to handle additional operations due to resource exhaustion. For example, if a file descriptor isn’t released quickly, it could prevent an application from opening new files, ultimately causing system instability. Consider the example below, where a BufferedReader object is used to read from a file. In the original code (Figure 1), the reader isn’t closed properly, resulting in a resource leak. Historically, developers relied on try/catch/finally blocks to handle such cases, but missing or incorrect finally blocks often led to leaks. Modern Java best practices recommend the try-with-resources statement, which significantly reduces boilerplate code and ensures resources are released safely, even if exceptions occur during execution. Figure 1: Origin...