The document compares Eclipse extensions and OSGi services. Extensions use XML and are static, while services are programmatic and dynamic. Extensions have a one-to-many coupling, while services have a many-to-many coupling without coupling. Declarative services separate service logic from installation/management and allow for optional/mandatory, unary/multiple, and static/dynamic configuration. The document recommends extensions for stable plug-ins and services for hot deployment/dynamic updates or quick projects within a domain.

1. Eclipse Extensions
vs.
OSGI Services
by N.Fastovsky

2. Comparison
EXTENSION POINTS OSGI SERVICES
XML based (PDE tool Programmatic
support) (Service is a POJO)
Static – “stale data” Dynamic (NPE &
issues Multi-Thread issues)
Coupling – “one-to- NO Coupling –
many” “many-to-many”
Copyright 2009 Tikal Knowledge, Ltd. | 2 |

3. Copyright 2009 Tikal Knowledge, Ltd. | 3 |

4. CLI Service Example
Copyright 2009 Tikal Knowledge, Ltd. | 4 |

5. Declarative Services
1. Separation of concerns: Service logic vs. Service
installation/management
2. Configuration:
Optional vs mandatory.
Unary vs multiple.
Static vs dynamic
Copyright 2009 Tikal Knowledge, Ltd. | 5 |

6. Declarative Services
Copyright 2009 Tikal Knowledge, Ltd. | 6 |

7. Rules of thumb
Building an RCP/Plug-in – go with
extensions (stable, PDE, Single
registry)
Hot deployment/Dynamic updates –
services.
Quick & Dirty or Within your domain –
services
Copyright 2009 Tikal Knowledge, Ltd. | 7 |

8. Running Eclipse Headless
Copyright 2009 Tikal Knowledge, Ltd. | 8 |

9. CLI SERVICE EXAMPLE
Copyright 2009 Tikal Knowledge, Ltd. | 9 |