The ModiTect project aims at providing productivity tools for working with the Java 9 module system ("Jigsaw"). Currently it supports the following two tasks:
- Generating module-info.java descriptors for given artifacts
- Adding module descriptors to existing JAR files
In future versions functionality may be added to work with tools like jlink, jmod etc. under Maven and other dependency management tools in a comfortable manner.
ModiTect's functionality is currently exclusively exposed through a Maven plug-in. The core implementation is a separate module, though, so that plug-ins for other build systems such as Gradle could be written, too.
To create a module-info.java descriptor for a given artifact, configure the generate-module-info goal as follows:
...
<plugin>
<groupId>org.moditect</groupId>
<artifactId>moditect-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
<executions>
<execution>
<id>generate-module-info</id>
<phase>generate-sources</phase>
<goals>
<goal>generate-module-info</goal>
</goals>
<configuration>
<modules>
<module>
<artifact>
<groupId>com.example</groupId>
<artifactId>example-core</artifactId>
<version>1.0.0.Final</version>
</artifact>
<additionalDependencies>
<dependency>
<groupId>com.example</groupId>
<artifactId>example-extended</artifactId>
<version>1.0.0.Final</version>
</dependency>
</additionalDependencies>
<moduleName>com.example.core</moduleName>
<exportExcludes>
<exportExclude>com\.example\.core\.internal\..*</exportExclude>
</exportExcludes>
</module>
<module>
...
</module>
</modules>
</configuration>
</execution>
</executions>
</plugin>
...This will generate a module descriptor at target/generated-sources/com.example.core/module-info.java.
For each module to be processed, the following configuration options exist:
artifact: The GAV coordinates of the artifact for which a descriptor should be generated (required)additionalDependencies: Additional artifacts to be processed; useful if the main artifact depends on code from another artifact but doesn't declare a dependency to that one (optional)moduleName: Name to be used within the descriptor; if not given the name will be derived from the JAR name as per the naming rules for automatic modules (optional)exportExcludes: Regular expressions allowing to filter the list of exported packages (optional)
It is also possible to run this goal directly, specifying the different options as JVM parameters like this:
mvn moditect:generate-module-info \
-Dmoditect.artifact=com.example:example-core:1.0.0.Final \
-Dmoditect.moduleName=com.example.core \
-Dmoditect.additionalDependencies=com.example:example-extended:1.0.0.Final -Dmoditect.exportExcludes=com\.example\.core\.internal\..*
To add a module descriptor for a given artifact, configure the generate-module-info goal as follows:
...
<plugin>
<groupId>org.moditect</groupId>
<artifactId>moditect-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
<executions>
<execution>
<id>add-module-infos</id>
<phase>generate-resources</phase>
<configuration>
<outputDirectory>${project.build.directory}/modules</outputDirectory>
<modules>
<module>
<artifact>
<groupId>com.example</groupId>
<artifactId>example-core</artifactId>
<version>1.0.0.Final</version>
</artifact>
<moduleInfoSource>
module com.example.core {
requires java.logging;
exports com.example.api;
provides com.example.api.SomeService
with com.example.internal.SomeServiceImpl;
}
</moduleInfoSource>
</module>
<module>
...
</module>
</modules>
</configuration>
</execution>
</executions>
</plugin>
...The POM file in integrationtest shows a more complete example. It adds module descriptors for Undertow Core and its dependencies, i.e. it allows to run the Undertow web server based on Java 9 modules.
Run
mvn clean install -pl integrationtest
to build the example. You then can start Undertow by executing
java --module-path integrationtest/target/modules --module com.example
Then visit http://localhost:8080/?name=YourName in your browser for the canonical "Hello World" example.
ModiTect is not yet deployed to Maven Central or any other repo server.
Instead clone it from GitHub (https://github.com/moditect/moditect.git)
and build it locally by running mvn clean install.
ModiTect is using a non-released version of ASM. As this version is not available in Maven Central yet, it has been copied into this project for the time being. It is based on revision r1843 of svn://svn.forge.objectweb.org/svnroot/asm/branches/ASM_6_FUTURE/asm. Once ASM 6 has been released in a version supporting the latest JDK 9 builds, ModiTect will use that official ASM version.
ModiTect currently represents the result of one weekend's work. I.e. it's a very basic proof-of-concept of this point. Not all features of module-info.java files are supported yet and it generally has lots of rough edges. Use it at your own risk.
Adding module descriptors to existing JARs is the first functionality implemente in ModiTect. Potential future developments include:
- Update existing module descriptors (e.g. to remove/replace a requires clause)
- Install/Deploy updated (modularized) JARs with a new name/classifier etc.
- Facilitate creation of jlink image directories
- YOUR ideas :)
ModuleTools by Remi Forax shows how to assemble module descriptors using ASM.
ModiTect is licensed under the Apache License version 2.0. ASM is licensed under the 3 clause BSD license (see the license.txt file in the asm directory).