Introduce OSGi

Introduce OSGiBlueDavyhttp://www.osgi.org.cnhttp://blog.bluedavy.cn

1.02007-10-28

23/4/2223/4/22 22 OSGi China User Group: http://www.osgi.org.cn 致力于致力于 OSGiOSGi 的推广和发的推广和发展展

Agenda Play OSGi Who use OSGi What is OSGi OSGi R4 Implemention How to develop OSGi app OSGi Resources

http://www.osgi.org.cn/


Play OSGi Let’s see a short demo

First we see an bulletin application,but only have bulletin list function;

We want to add new bulletin,so we find newbulletin module from module respository,then install & start it,now we can add new bulletin;

We see the feature of OSGi application modularity dynamic,”Plug and Play” extensionable these features are supported by OSGi,the meaning is that you d

on’t need realize those features yourself,what you need do is just use it






Who use OSGi IBM

Websphere RSA

BEA microServices,All BEA product will be based on microServices

Eclipse Apache

Struts 2 Spring

Spring-OSGi Simens,Nokia,BMW,Cisco etc. SAP,Oracle,IONA etc. are interested in OSGi,and be OS

Gi EEG member






What is OSGiDynamic Module System For JavaJSR232 JSR291Universal MiddlewareBest practice guide and support for building mod

ularity/dynamic/extensionable system Modularity with rule; Dynamic support for module,OSGi service,configurati

on; Extension support with OSGi service.



OSGi Basic Concepts Modularity

Define module in OSGi; Publish functions for other

modules; Use functions provided by other modules.

BundleBundle

JAVA

Operating System

Hardware

OSGi Framework

Serviceregistry

packagespackages



Define module in OSGiIn OSGi module compose of one or more bundle

s;Bundle is a normal jar file,the difference is its Ma

nifest.mf file,OSGi add some specical header info property to declarative bundle,such as: bundle-version,export-package,import-package



Publish functions for other bundlesadd export-package header info to provide pack

age for other bundles to use,such as cn.org.osgi.ppt.service;

add Fragment-Host header info to provide all resources for host bundle to use;

publish OSGi service for other bundles; Use BundleContext.registerService to register normal

java interface as OSGi service; Write xml with rule to declarative normal java class as

OSGi component,and provide service interface for other bundles,such as:



Use functions provided by other modulesadd import-package header info to import packa

ges provided by other bundles,then you can use the java class in those packages;

add require-bundle header info to use all export packages and resources provider by bundle;

use OSGi service provided by other bundles; Use BundleContext.getService to get OSGi service pr

ovided by other bundles; Write xml with rule to declarative normal java class as

OSGi component,and inject OSGi service provided by other bundles,such as:



OSGi Basic Concepts Dynamic

Bundle lifecycle OSGi component lifecycle Handle the dynamic

– when bundle lifecycle changed;– when OSGi component lifecycle changed;– when configuration changed;– when framework changed;– when custom event published;



Bundle lifecycleOSGi provide an API for manageing bundles life

cycle (Install/Resolve/Start/Stop/Refresh/Update/Uninstall),so OSGi framework RI will control bundle lifecycle self;

INSTALLED

RESOLVED

UNINSTALLED

ACTIVE

STOPPING

STARTING

start

stop



OSGi component lifecycle Component that provide no service;

when all need OSGi services(exclued optional service) are usable,the component will be actived;

Component that provide services; when all need OSGi services(exclued optional service) are usable; other component call this OSGi service implemention.



Handle the dynamic when bundle lifecycle changed;

OSGi component lifecycle will change automatically; OSGi will handle bundle lifecycle dynamic self;

when OSGi component lifecycle changed; OSGi service tracker can be used to monitor OSGi service; Declarative Services use bind-method,unbind-method to notify the dyna

mic of OSGi service. when configuration changed;

Configuration Admin Service automatically notify the configuration change.

when framework changed; FrameworkEventListener can be implemented to monitor framework.

when custom event published; EventAdmin Service can to used to publish & handle custom event.



OSGi Basic Concepts Extensionable

Service filter supported by OSGi can be used to extension function;

Multi service reference supported by OSGi can be used to extension function;

Extension point provided by Equinox can be used to extension function.






OSGi R4 Implemention Equinox

Realized by Eclipse team; As the OSGi R4 RI; http://www.eclipse.org/equinox. Used by Eclipse RCP & Eclipse other products.

Felix Realized by Apache Team; http://felix.apache.org.






How to develop OSGi app Get started Write your first bundle Deploy & Manage first bundle Publish and use OSGi Service FAQ



Get started Download Eclipse from www.eclipse.org Download Equinox bundles from

www.eclipse.org/equinox most bundles exist in eclipse


http://www.eclipse.org/equinox


Write your first bundle New plugin-project,select this plug-in is targeted

to run with an OSGi framework in project wizard page;



Write your first bundle Then enter the plug-in content page Write associate info,then click finish to create th

e project.



Write your first bundle Write activator class

Say ‘hello’ when bundle started; Say ‘byebye’ when bundle stopped;



Deploy & Manage first bundle Deploy in eclipse Deploy outside alone Manage bundle in console



Deploy in eclipseOpen run dialog,new in Equinox OSGi Framewo

rk, select Workspace Plug-ins and org.eclipse.osgi in Target platform;



Deploy in eclipseClick Run button,then you can see this in consol

e;



Deploy outside alone Create equinox framework app outside alone first;

create Equinox directory,then create configuration,plugins directory in Equinox directory;

put org.eclipse.osgi.jar & org.eclipse.osgi.services.jar to plugins directory;

create config.ini in configuration directory,content in config.ini like this:

osgi.noShutdown=trueosgi.bundles=org.eclipse.osgi.services_3.1.100.v20060601.jar@startosgi.bundles.defaultStartLevel=4osgi.configuration.cascaded=falseeclipse.ignoreApp=true

create run.bat in Equinox directory,content in run.bat(windows) like this:@echo offjava -jar plugins/org.eclipse.osgi_3.2.1.R32x_v20060919.jar - configuration configuration -console



Deploy outside aloneStart equinox framework and install first bundle i

n OSGi console; install first bundle use directory mode;

– Input command like this in OSGi console: install file:/D:\work\workspace\OSGi-Bulletin\FirstBundle

install first bundle use jar file; – package first bundle into jar file;

– Export the project as deployable plug-ins and fragments– Input command like this in OSGi conosle:

install file:/D:\Opendoc\Equinox\plugins\FirstBundle_1.0.0.jar



Manage bundle in consoleuse ss to find bundle id

use start,stop,update,uninstall to manage bundle with bundle id start 2 (start bundle) stop 2 (stop bundle) update 2 (update bundle on the fly) uninstall 2 (uninstall bundle)



Publish OSGi Service Use OSGi declarative services to publish and use OSGi Service,the

n when you run OSGi application,you need install Equinox DS plugin;

Create ServiceBundle to publish OSGi service; Create cn.org.osgi.ppt.service.HelloService Interface; Create cn.org.osgi.ppt.component.HelloComponent to implemention Hel

loService; Publish HelloService as OSGi service using DS component xml;

<component name="HelloComponent"><implementation class="cn.org.osgi.ppt.component.HelloComponent"/><service>

<provide interface="cn.org.osgi.ppt.service.HelloService"/></service>

</component> Add component.xml to MANIFEST.MF Service-Component property Export package cn.org.osgi.ppt.service



Use OSGi Service Add cn.org.osgi.ppt.service to import-package; Use HelloService in firstbundle with two kind methods;

context.getService method– In Activator class: ServiceReference serviceRef=context.getServiceReference(HelloService.class.getName()); if(serviceRef!=null){ HelloService service=(HelloService) context.getService(serviceRef); service.say("Activator"); }

Declarative Services method– create cn.org.osgi.ppt.firstbundle.FirstComponent class with inject service method:

public void setService(HelloService service){this.service=service;}

public void unsetService(HelloService service){if(this.service!=service) return;this.service=null;System.out.println("HelloService 不可用 ");}

– write ds component xml to inject OSGi service;– Add component.xml to MANIFEST.MF Service-Component property






OSGi Resources OSGi R4 Specifications 《OSGi实战》Opendoc 《OSGi进阶》Opendoc http://www.osgi.org http://www.osgi.org.cn http://www.aqute.biz http://blog.bluedavy.cn


http://www2.osgi.org/Specifications/HomePage

http://www.osgi.org.cn/opendoc/OSGI_Opendoc.rar



http://www.osgi.org.cn/opendoc/osgiopendoc2.pdf



http://www.osgi.org/


http://www.aqute.biz/

http://blog.bluedavy.cn/

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Introduce OSGi