Extensions Directory for Deploying Builtins

It is possible to package one or multiple builtins in an OSGI bundle. The bundle must register a BuiltinProvider service to announce its builtin contributions to OntoBroker. Most simply, a declarative service in OSGI can be used for this purpose.

The BuiltinProvider interface has one single method to return the builtin classes of this extension bundle.

package com.ontoprise.ontobroker.kernel.builtinsystem;

public interface BuiltinProvider {

Collection<Class<? extends IBuiltin>> getBuiltins();

}

To implement this interface, create a class like the following example

package com.acme.mypackage

import java.util.*

import com.ontoprise.ontobroker.api.extension.builtin.IBuiltin;

public class MyBuiltinsProvider implements BuiltinProvider {

@Override

public Collection<Class<? extends IBuiltin>> getBuiltins() {

ArrayList<Class<? extends IBuiltin>> list = new ArrayList<Class<? extends IBuiltin>>();

list.add(MyBuiltin.class);

return list;

}

Package this class together with your builtin classes in a JAR file. You need to add an OSGI conform META-INF/MANIFEST.MF file to the JAR.

META-INF/MANIFEST.MF (minimalistic version)

Manifest-Version: 1.0

Bundle-ManifestVersion: 2

Bundle-Name: MyBuiltins

Bundle-SymbolicName: com.acme.mypackage

Bundle-Version: 1.0.0

Require-Bundle: com.ontoprise.ontobroker.base,com.ontoprise.ontobroker.datamodel

Import-Package: org.osgi.framework,org.osgi.service.component

Export-Package: com.acme.mypackage

Service-Component: OSGI-INF/component.xml

In addition, to register the OSGI service the simplest way is to define it as declarative service in an OSGI-INF/component.xml.

OSGI-INF/component.xml

<?xml version="1.0" encoding="UTF-8"?>

<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="com.acme.mypackage">

</service>

</scr:component>

Also see the example in the Eclipse project located at $ONTOBROKER_HOME/interfaces/development/Code Examples