Xored Integrity Maven Plugin


This plugin helps you to ensure build integrity in case of a large multi-module project with branchy structure. For such a project, it is easy to forget to add a pom.xml file for a new module, or add a new module to the list of nested modules of the parent module. Especially, when you can run the project without Maven, e.g. when it’s an Eclipse RCP application, which is built by Maven/Tycho on CI server, but developers run it from the workspace in Eclipse.

Things get worse, when many people with wide range of experience and responsibilities contribute to the project (some of them might not know about Maven at all), or when the fact, that a module is missing, is not so easy to notice (e.g. missing Eclipse plugin typically doesn’t break a build).

This plugin scans project directory structure in attempt to find missed (not included to the build) modules. If it finds any missed modules, it marks the build failed.

Basic Setup

Add this to the parent pom of your project:


(* When I was writing this doc, the latest version was 1.0.3.)

After that, you can continue to build you project as usual (e.g. mvn clean install).

The plugin gets a list of all module directories of your project (reactor project directories). Then, it determines the root of the entire project (the common root of all reactor project directories). When it’s done, it scans the filesystem recursively starting from the root. For each directory, which looks like a module, it checks, if it exists in the list of reactor projects. If it doesn’t, it is a missed module, and the plugin marks the build failed.

Configuration & Example

How does the plugin decide, if a directory looks like a module? When no configuration is given, each directory, which contains pom.xml file, is a module. You may redefine this behaviour by specifying includes/excludes configuration elements. They are Ant patterns, which are applied to paths, relative to the project root. It is implied, that each pattern starts with **/ and ends with /**. You should not specify this explicitly.

Suppose, you have the following config in your parent pom:


This means, that

  • Sub-directories, which match any of the patterns **/pom.xml/**, **/feature.xml/**, **/META-INF/MANIFEST.MF/**, are modules. Note, that exact module directory is determined by the first path element, which matches meaningful part of the pattern (not **/). So, if you have a/b/c/META-INF/MANIFEST.MF, a/b/c would be a module, but not a/b/c/META-INF. If you want a/b/c/META-INF to be a module, you should specify <include>MANIFEST.MF</include> instead.
  • Sub-directories, which match any of the patterns **/repository/**, **/product/**/bin/**, **/platform/**/META-INF/maven/**/pom.xml/**, **/*.updatesite/build/**, are not modules, even if they match any of the includes patterns.

Suppose, that this is your project structure:

├── platform
│   ├── features
│   │   ├── feature-1
│   │   │   ├── feature.xml
│   │   │   └── pom.xml
│   │   ├── feature-1.updatesite
│   │   │   └── build
│   │   │       └── feature.xml
│   │   └── feature-2
│   │       └── feature.xml
│   ├── plugins
│   │   ├── plugin-1
│   │   │   ├── META-INF
│   │   │   │   └── MANIFEST.MF
│   │   │   └── pom.xml
│   │   ├── plugin-2
│   │   │   └── META-INF
│   │   │       ├── maven
│   │   │       │   └── a
│   │   │       │       └── pom.xml
│   │   │       └── MANIFEST.MF
│   │   └── plugin-3
│   │       └── META-INF
│   │           └── this-is-not-a-module.txt
│   ├── repository
│   │   └── q
│   │       └── pom.xml
│   └── pom.xml
├── product
│   └── a
│       └── b
│           └── bin
│               └── META-INF
│                   └── MANIFEST.MF
└── releng
    └── parent
        └── pom.xml

As you can see, this resembles Eclipse RCP project, which is built by Maven/Tycho. Suppose also, that you run it like this:

$ cd releng/parent
$ mvn verify

In this case, modules are:

  • platform/features/feature-1
  • platform/features/feature-2
  • platform/plugins/plugin-1
  • platform/plugins/plugin-2
  • platform
  • releng/parent

Any other directory is not a module.

Modules platform/features/feature-2 and platform/plugins/plugin-2 are surely missed, since they lack pom.xml. So, the build will fail. The other modules may be missed as well, if they are not included to the parent poms, thus not included to the reactor build.


The plugin automatically excludes build directories of reactor projects, so you should not explicitly specify anything like <exclude>path/to/my/module/target</exclude>.