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Ditch XML: Declare Service Annotations and Simplify Plug-in Development

This guide explains how to use OSGi Declarative Service (DS) annotations to simplify plug-in development by eliminating the need for XML configuration. By leveraging DS annotations, you can optimize your development process and improve maintainability.

📖 Reference Links​

Eclipse has also modified the Felix SCR (Service Component Runtime) to make the API documentation more precise. You can find additional details in the Eclipse documentation.

🛠️ How to Use DS Annotations​

1. Eclipse Version​

Ensure you are using Eclipse Oxygen or a newer version.

2. Configure Eclipse for DS Annotations​

Set up Eclipse to support DS annotations:

  1. Go to Window > Preferences > Plug-in Development > DS Annotations.
  2. Configure the settings as shown in the image below:

Eclipse DS Annotation Configuration

3. Update Your Plug-in Manifest​

Add the following package to the Import-Package section of your plug-in's MANIFEST.MF file:

org.osgi.service.component.annotations

Service Factory​

For factory classes, add an annotation like the one below:

Sample Code​

@Component(
    property = {"service.ranking:Integer=2"},
    service = org.adempiere.base.IProcessFactory.class
)
public class JRProcessFactory implements IProcessFactory {
    // Implementation here
}
info
  • You don't need to declare a service if you directly implement a service interface like IProcessFactory.
  • For array properties, repeat the property name for each value.

Event Handler​

For event handler classes that extend from AbstractEventHandler, add an annotation like the one below:

Sample Code​

@Component(
    reference = @Reference(
        name = "IEventManager",
        bind = "bindEventManager",
        unbind = "unbindEventManager",
        policy = ReferencePolicy.STATIC,
        cardinality = ReferenceCardinality.MANDATORY,
        service = IEventManager.class
    )
)
public class SampleEventHandler extends AbstractEventHandler {
    // Implementation here
}

By using DS annotations, you can eliminate the need for XML configuration, making your plug-in development process faster and more efficient.