Architecture OSGi

osgi service gateway architecture

osgi (open service gateway initiative) java framework developing , deploying modular software programs , libraries. each bundle tightly coupled, dynamically loadable collection of classes, jars, , configuration files explicitly declare external dependencies (if any).

the framework conceptually divided following areas:

bundles
bundles normal jar components manifest headers.
services
the services layer connects bundles in dynamic way offering publish-find-bind model plain old java interfaces (pojis) or plain old java objects (pojos).
services registry
the application programming interface management services (serviceregistration, servicetracker , servicereference).
life-cycle
the application programming interface life cycle management (install, start, stop, update, , uninstall) bundles.
modules
the layer defines encapsulation , declaration of dependencies (how bundle can import , export code).
security
the layer handles security aspects limiting bundle functionality pre-defined capabilities.
execution environment
defines methods , classes available in specific platform. there no fixed list of execution environments, since subject change java community process creates new versions , editions of java. however, following set supported osgi implementations:

cdc-1.0/foundation-1.0
cdc-1.1/foundation-1.1
osgi/minimum-1.0
osgi/minimum-1.1
jre-1.1
from j2se-1.2 j2se-1.6