This project implements the ANT / Gradle task and Maven Mojo announced in the Generics Policeman Blog. It checks Java byte code against a list of "forbidden" API signatures.

I started to hack a tool as a custom Apache Ant task using ASM (Lightweight Java Bytecode Manipulation Framework). The idea was to provide a list of methods signatures, field names and plain class names that should fail the build, once bytecode accesses it in any way. A first version of this task was published in as Apache Lucene issue LUCENE-4199, later improvements was to add support for fields (LUCENE-4202) and a sophisticated signature expansion to also catch calls to subclasses of the given signatures (LUCENE-4206).

This project was started as a fork of the internal Apache Ant Task. It additionally provides a Apache Maven Mojo, that can check your application classes against forbidden signatures, too. For simple use-cases, a command line interface is available, too. In version 2.0 Gradle support was added.

The Apache Ant task and the Apache Maven Mojo are available for download or use with Maven/Ivy through Maven Central and Sonatype repositories. The Gradle plugin is available through the Gradle Plugin portal, but it's also hosted on Maven/Sonatype. Nightly snapshot builds are done by the Policeman Jenkins Server and can be downloaded from the Sonatype Snapshot repository.

The current version is 3.7, released on 2024-03-24. Changes for each released version are listed on the following page: Changes

• Apache Ant Usage Instructions

• Apache Maven Usage Instructions

• Gradle Usage Instructions (version 2.0+)

• Command Line Usage Instructions (version 1.1+)

• Syntax of Forbidden Signatures

• Nightly Snapshot Documentation (detailed)