Searching for Replacement Classes

TL;DR

This paper introduces ClassFinder, a system that effectively retrieves replacement classes for a given class in Java, using a combination of embeddings and type analysis to aid developers in code adaptation tasks.

Contribution

ClassFinder uniquely combines embeddings and type analysis to identify and rank replacement classes, providing mappings to assist developers in replacing components.

Findings

Successfully retrieved meaningful replacements for 24 Java classes.

Produced complete, functionally identical class mappings in many cases.

Operated on a dataset of approximately 600,000 open source Java classes.

Abstract

Software developers must often replace existing components in their systems to adapt to evolving environments or tooling. While traditional code search systems are effective at retrieving components with related functionality, it is much more challenging to retrieve components that can be used to directly replace existing functionality, as replacements must account for more fundamental program properties such as type compatibility. To address this problem, we introduce ClassFinder, a system which given a query class Q, and a search corpus S, returns a ranked subset of classes that can replace Q and its functionality. ClassFinder produces afield and method mapping between the classes that can provide useful hints to a developer and can be used to effectively refine the ranking of candidate replacement classes. Our technique leverages the complementary strengths of a distributed embeddings-based search and type-based analysis, using the former to prune down candidates for an optimization-based approach based on the latter. ClassFinder retrieves replacement classes, along with a type-aware field/method mapping between classes. We evaluate ClassFinder on a search space of ~600thousand open sourceJava classes. Querying ClassFinder with 24 known Java classes provided meaningful replacement classes and mappings, in many cases producing complete mappings with functionally identical replacement classes.