Roseau

Roseau (/ʁozo/) is a fast and accurate tool for detecting breaking changes between Java library versions, similar to tools like japicmp or Revapi. Whether you're a library maintainer or upgrading dependencies in your projects, Roseau helps ensure backward compatibility across versions. Roseau analyzes both JAR files and source code, is highly configurable, generates reports in HTML, JSON, and Markdown, and includes a dedicated Maven plug-in.

Get the latest release View on GitHub

Quick Example

When invoked, Roseau extracts the API surface of each version and diffs them to identify breaking changes following a set of well-defined detection rules. Library versions can be passed as local JAR files or source directories, or can be fetched remotely from Maven:

$ roseau --diff --v1 library-1.0.0.jar --v2 library-2.0.0.jar
Breaking changes found: 3 (2 binary-breaking, 2 source-breaking)
✗ com.pkg.A TYPE_REMOVED
  ✗ binary-breaking ✗ source-breaking
  → com/pkg/A.java:4
⚠ com.pkg.B.f FIELD_NOW_STATIC
  ✗ binary-breaking ✓ source-compatible
  → com/pkg/B.java:18
★ com.pkg.C TYPE_NEW_ABSTRACT_METHOD [toOverride()]
  ✓ binary-compatible ✗ source-breaking
  → com/pkg/C.java:210
$ roseau --diff --v1 com.example:lib:1.0.0 --v2 /path/to/v2/src/main/java
[...]

An example HTML report is available here.