jSparrow vs PolyglotPiranha

jSparrow is a Java cleanup and refactoring tool for Eclipse IDE and Maven, running on Linux, macOS and Windows. It lists more than 90 refactorings for Java 1.1 and later, with project-level and batch operation. Diff View compares original and proposed code so changes can be reviewed before application. Markers suggest quick fixes during programming, and the base product includes them at no charge. Interactive rules can replace standard output with logging, rename fields to Java naming conventions and remove unused methods, fields and types. Analysis and refactoring run offline, and the FAQ says code is not sent to external servers or third parties. Internet access is required to persist locked refactorings through the NetLicensing API; offline validation servers are available. The site describes jSparrow as open-source, with no license needed since version 4.20.0. Twenty rules are free; paid licenses are $169 a month or $1,325 a year.

PolyglotPiranha is a free, multilingual structural search-and-replace engine for code cleanup. It can refactor stale feature-flag code when given a flag name, expected behavior, and configured feature-flag API rules. Rules can form graphs, and built-in language-specific cleanups include simplifying boolean expressions and if-else statements, removing empty declarations and files, and inlining local variables. Queries and filters may use Tree-sitter queries, regular expressions, or Piranha’s concrete syntax. The project is available as a Python library and command-line tool, with the Python API wrapping the CLI. The CLI lists Java, Swift, Python, Kotlin, Go, TSX, and TypeScript as target languages. Dry runs prevent in-place rewriting and produce summaries of matches, rewrites, and resulting file content. API configuration requires code path, configuration path, target language, and substitutions, with optional rules.toml and edges.toml files. Python installation uses pip; the CLI can be built with Rust and Cargo or obtained from releases. Piranha is Apache 2.0, provided as is, and not an official Uber product.