META-INF/services generator -

What is this?

This tiny library is an annotation processor that automatically generates META-INF/services/* file from annotations that you placed on your source code, thereby eliminating the need for you to do it by yourself.

Usage

On classes that you'd like listed as service providers, put @MetaInfServices annotation. As long as you only have one interface or one super class, that type is assumed to be the contract. So given the example below:

import org.kohsuke.MetaInfServices;

@MetaInfServices
public class MyProvider implements SomeContract {
  ...
}

You get the META-INF/services/com.example.SomeContract file whose content is org.acme.MyProvider.

If you have multiple interfaces and/or base type, the library cannot infer the contract type. In such a case, specify the contract type explicitly by giving it to @MetaInfServices like this:

import org.kohsuke.MetaInfServices;

@MetaInfServices(ContractType.class)
public class MyProvider extends AbstractSet implements Comparable, Serializable, Closeable {
  ...
}

When you use javac in JavaSE6, META-INF/services/* files are generated automatically. No additional compiler switches are necessary. This library handles incremental compilation correctly, too.

Tips for Maven users

metainf-services.jar is only necessary during the compilation, so specify it as an optional dependency to avoid having the jar in the runtime. This will save 6KB in the runtime footprint.

<dependency>
  <groupId>org.kohsuke.metainf-services</groupId>
  <artifactId>metainf-services</artifactId>
  <version>1.1</version>
  <optional>true</optional>
</dependency>

META-INF/services generator