This maven plugin generates services files for the ServiceLoader introduced in Java 6 : https://docs.oracle.com/javase/9/docs/api/java/util/ServiceLoader.html
Use
for example:
<build>
<plugins>
<plugin>
<groupId>eu.somatik.serviceloader-maven-plugin</groupId>
<artifactId>serviceloader-maven-plugin</artifactId>
<version>1.3.1</version>
<configuration>
<services>
<param>com.foo.Dictionary</param>
<param>com.foo.Operation</param>
</services>
</configuration>
<executions>
<execution>
<goals>
<goal>generate</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>this will generate these files:
- META-INF/services/com.foo.Dictionary
- META-INF/services/com.foo.Operation
by scanning the generated classes and finding all non-abstract/non-interface implementations of the service interfaces. The plugin itself has no Java 6 dependency
Excludes / includes
Additionally it is possible to filter implementation classes via includes and excludes section in the configuration. The class name notation is the same as for the services section.
for example:
<build>
<plugins>
<plugin>
<groupId>eu.somatik.serviceloader-maven-plugin</groupId>
<artifactId>serviceloader-maven-plugin</artifactId>
<version>1.3.1</version>
<configuration>
<services>
<param>com.foo.Dictionary</param>
<param>com.foo.Operation</param>
</services>
<includes>
<include>*.RightClass*</include>
</includes>
</configuration>
<executions>
<execution>
<goals>
<goal>generate</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>This should add only implementation classes that begin with RightClass*.
Missing Service Classes
The default action when a service class is missing is to fail the build.
If you want to ignore this service, you can use the failOnMissingServiceClass option (true by default).
for example:
<build>
<plugins>
<plugin>
<groupId>eu.somatik.serviceloader-maven-plugin</groupId>
<artifactId>serviceloader-maven-plugin</artifactId>
<version>1.3.1</version>
<configuration>
<failOnMissingServiceClass>false</failOnMissingServiceClass>
<services>
<param>com.foo.MissingService</param>
</services>
</configuration>
<executions>
<execution>
<goals>
<goal>generate</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>Example
A example project is provided and can be run like this:
$ mvn clean install
...
[INFO] Generating service file .../example/target/classes/META-INF/services/eu.somatik.serviceloader.Operation
[INFO] + eu.somatik.serviceloader.SimpleOperation
...
$ java -jar target/example-1.0-SNAPSHOT.jar
Found service implementation: eu.somatik.serviceloader.SimpleOperation@579a19fd
Hello world
Release
Note: do export GPG_TTY=$(tty) first if you have gpg: signing failed: Inappropriate ioctl for device errors
mvn -P release release:clean release:prepare
mvn -P release release:perform