OSGi-enabled Java EE Applications using GlassFish at JCertif 2011
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This document discusses OSGi-enabled Java applications in GlassFish. It provides an overview of OSGi and how it is used in GlassFish to provide modularity. Key points include: - OSGi allows applications to be broken into modules or bundles that can be installed, uninstalled, started and stopped dynamically without restarting the container. - In GlassFish, all modules are OSGi bundles which run on top of the OSGi framework. This provides stronger modularity compared to a non-OSGi application server. - Benefits of using OSGi in GlassFish include demanding stronger modularity, enabling custom tailored application servers, and lazy loading of bundles based on usage patterns.
OSGi-enabled Java EE Applications using GlassFish at JCertif 2011
- 1. <Insert Picture Here> OSGi-enabled Java EE Applications in GlassFish Arun Gupta, Java EE & GlassFish Guy blogs.oracle.com/arungupta, @arungupta
- 2. The following/preceding is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle. 2
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- 7. Generally complex ... • 13 assembly missions • 16 pressurized modules • 35k cubic feet • 400 metric tons ~ 400K kg ~ 882K lbs • 173 – 286 miles above Earth • Average speed: 17,227 mph • 15.7 orbits/day • Estimated cost: $157 billion 7
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- 9. The OSGi Alliance is a worldwide consortium of technology innovators that advances a proven and mature process to assure interoperability of applications and services based on its component integration platform. 9
- 10. OSGi Alliance provides ... • Specifications • Reference Implementation • Test Suites • Certifications 10
- 11. What is OSGi Specification ? • Delivered by OSGi Alliance • Originally for embedded devices, set top boxes, network • Architecture for modular application development in Java • Breaks applications into “modules” or “bundles” • Can install, uninstall, start, and stop each bundle dynamically without restarting container • Multiple versions are supported • Dependencies explicitly defined with clear boundaries 11
- 12. “JAR Hell” • JAR is a build-time and deploy-time concept, not run-time • Based on the ZIP file format • No metadata to indicate dependencies • Multiple versions of JARs cannot be loaded • All “public” classes are public • Access modifiers are for packages, not JAR 12
- 13. OSGi Layers Service Life Cycle Module Execution Environment 13
- 14. OSGi Bundle – Just a JAR File! Export-Package Import-Package Java Classes, Static Files, … Bundle-ClassPath (bundle private) ... META-INF/MANIFEST.MF Persistent OSGI-OPT (docs, source code, ...) Atomic 14
- 15. Bundle is identified by ... • Bundle Identifier • Unique for the lifetime • getBundleId() • Bundle Location • Unique location of the bundle • getLocation() • Bundle Symbolic Name and Version • Globally unique identifier • getSymbolicName(), getVersion() 15
- 16. Java Classes, Static Files, ... Service META-INF/MANIFEST.MF ... Export-Package ... Client Java Classes, Static Files, ... META-INF/MANIFEST.MF ... Import-Package ... 16
- 17. Interaction between layers register / unregister get / unget Service manage start / stop Life Cycle Bundle install uninstall classload Module execute EE 17
- 18. Bundle State Diagram update refresh install INSTALLED STARTING update rt resolv sta refresh e RESOLVED ACTIVE uninstal stop l STOPPING Each bundle installation is new 18
- 19. OSGi Containers http://stackoverflow.com/questions/560794/what-osgi-container-do-you-recommend 19
- 20. OSGi in GlassFish • GlassFish runs on top of OSGi • Felix is default, also runs on Equinox & Knopflerfish • Runs in an existing shell • 260+ bundles in 3.1 • All GlassFish modules are OSGi bundles • No OSGi APIs are used in GlassFish • HK2 provides abstraction layer http://blogs.oracle.com/arungupta/entry/totd_103_glassfish_v3_with http://blogs.oracle.com/arungupta/entry/totd_127_embedding_glassfish_in 20
- 21. GlassFish: Modular Platform REST REST SOAP SOAP High High Clustering Clustering JMS JMS Web Services Web Services Web Services Web Services Availability Availability Web Web Connection Connection Java Java JSF JSF EJB Container EJB Container Application Container Container Container Pooling (JCA) Pooling (JCA) Persistence Persistence Management Console Update Center Management CLI Naming Grizzly Framework Monitoring/ Injection Service Config Deploy Manager Security Monitor Configuration Cluster Serviceability/ Logging GlassFish V3 Core Transaction Security (Module Subsystem) Service Service Deployment Clustering OSGi OSGi Java SE Java SE 21
- 22. GlassFish v3 Runtime with OSGi GlassFish V3 modules Random OSGi Bundle (OSGi + extra metadata) Service OSGi HK2 Service layer Mapper Service Layer OSGi Bundle Management 22
- 23. Benefits of OSGi for GlassFish • Demands and enforces stronger modularity • Enables custom tailored App server • Lazy loading based on usage patterns • Successfully maintained quick startup • Available to GlassFish developers and users 23
- 24. Create an OSGi Bundle – Maven • Create a Maven project • Implement “BundleActivator” • Update “pom.xml” • Change packaging to “bundle” • Add dependencies on OSGI APIs • Use “maven-bundle-plugin” to package • Build the bundle http://blogs.oracle.com/arungupta/entry/totd_36_deploy_osgi_bundles 24
- 25. Create an OSGi bundle – NetBeans http://blogs.oracle.com/arungupta/entry/totd_125_creating_an_osgi 25
- 26. Create an OSGi bundle – NetBeans http://blogs.oracle.com/arungupta/entry/totd_125_creating_an_osgi 26
- 27. Create an OSGi bundle – Eclipse http://blogs.oracle.com/arungupta/entry/totd_126_creating_an_osgi 27
- 28. OSGi Bundles in GlassFish • asadmin deploy –type osgi • “cp”/“rm” glassfish/domains/domain1/autodeploy/bundles • telnet localhost 6666 • Apache Felix Web Console • REST Console bundle • Perl-based shell (Osgish) • VisualVM OSGi Plugin • Supports OBR • Discover and deploy dependencies together http://blogs.oracle.com/arungupta/entry/totd_118_managing_osgi_bundles 28
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- 30. Dynamic Discovery of OSGi service OSGi Export-Package API Service Registry Import-Package Impl Bundle-Activator Import-Package cker Client Service Tra Bundle-Activator Filters http://blogs.oracle.com/arungupta/entry/totd_131_dynamic_osgi_services 30
- 31. Why OSGi in Enterprise Apps ? • Improved modularity • Reusable bundles • Dependencies are more visible • Better isolation / Cleaner class loading model • Better version control • Faster deployment cycle • Better tools for deployment • Observable bundle life cycle • Service Tracking • Criteria-based service selection 31
- 32. Why Java EE in Enterprise Apps ? • Better API (JPA, JTA, JAXB, JNDI) • Better component model (Servlet, EJB, JAX-RS) • Better frameworks (JSF, CDI) • Ease-of-use (Annotations, Convention-over- configuration) • Platform provided integrated infrastructure services • Transaction, Security, Persistence, Remoting, ... • Many more reasons ... 32
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- 34. OSGi Enterprise Expert Group The OSGi Enterprise Expert Group (EEG) is chartered to define the technical requirements and specifications to tailor and extend the OSGi Service Platform to address information technology software infrastructure use cases found in enterprise business scenarios. http://www.osgi.org/EEG/HomePage 34
- 35. OSGi EEG Focus • Scaling, including multi-container and multi-process environments • Distributed and/or federated service model for • Multiple Service Platforms • External, heterogeneous systems • Requirements for extensions to the OSGi publish/find/bind service model • Enterprise-class life cycle and configuration management • Integration of established Java EE technology into OSGi 35
- 36. Hybrid Applications “A hybrid application is an OSGi bundle as well as a Java EE archive and hence has both an OSGi bundle context and Java EE context at runtime and can leverage capabilities of both the platforms.” 36
- 37. Why Hybrid Apps ? Best of both worlds!!! Why do you want to learn new APIs ? 37
- 38. Role of GlassFish • Provides a runtime for Hybrid Applications • Implements Java EE related OSGi services and standards • Don't have to assemble the bits • OSGi is no longer under the cover • Raises visibility from GlassFish developers to users 38
- 39. OSGi Compendium Specs in GlassFish • OSGi/HTTP Service • OSGi/Web Application (rfc #66) • OSGi/JTA (rfc #98) • OSGi/JDBC (rfc #122) • OSGi/JPA (rfc #143) • OSGi/JNDI (rfc #142, coming post 3.1) http://wikis.sun.com/display/GlassFish/3.1OSGi 39
- 40. OSGi/Web Application (rfc #66) • Web Application Bundle (WAB) • WAR + OSGi + Web-ContextPath Header • Can use all enterprise APIs include JPA with lazy loading • Sample manifest: Manifest-Version: 1.0 Import-Package: javax.servlet.http; javax.persistence Bundle-ClassPath: WEB-INF/classes/,WEB-INF/lib/entities.jar Bundle-Version: 1.0 Bundle-ManifestVersion: 2 Web-ContextPath: /hello Bundle-SymbolicName: test.hellowab • Wrapped WAR Support • webbundle: URL scheme 40
- 41. OSGi Declarative Services • Complications of Publish/Find/Bind • Long startup time • Memory footprint • Complex service programming model • OSGi services in Java EE @Resource(mappedName=”osgiName”) SomeOSGiService osgiService; • JNDI Lookup • Portable, no OSGi dependencies in application • Exported APIs visible to Java EE apps 41
- 42. OSGi Declarative Service <scr:component enabled="true" name="hello-service"> <implementation class="org.glassfish.samples.osgi.helloservice.impl.HelloImpl"/> <service servicefactory="false"> OSGI-INF/ <provide interface="org.glassfish.samples.osgi.helloservice.api.HelloService"/> </service> serviceComponents.xml <property name="service.pid" value="hello-service"/> </scr:component> Export-Package API Servlet Client ... import org.glassfish.samples.osgi.helloservice.api.HelloService; HelloImpl @WebServlet(urlPatterns={"/HelloClient"}) public class HelloClient extends HttpServlet { @Resource(mappedName="hello-service") HelloService helloService; @Resource(mappedName="howdy-service") HowdyImpl HelloService howdyService; ... http://blogs.oracle.com/arungupta/entry/totd_124_osgi_declarative_services 42
- 43. OSGi Declarative Services import org.apache.felix.scr.annotations.Component; import org.apache.felix.scr.annotations.Service; import org.glassfish.samples.osgi.helloservice.api.HelloService; maven- bundle- @Component(name="hello-service") plugin @Service public class HelloImpl implements HelloService { maven- public String sayHello(String name) { scr- return "Hello " + name; plugin } } http://blogs.oracle.com/arungupta/entry/totd_124_osgi_declarative_services 43
- 44. JAX-WS & OSGi Artifacts WSDL JAX-WS JAX-WS Endpoint Client Business Method 44
- 45. JAX-WS & OSGi Artifacts WSDL JAX-WS JAX-WS Endpoint Client Business Delegate Method Query Registry OSGi OSGi Register Service Service Bundle Registry Business Method http://blogs.oracle.com/arungupta/entry/totd_130_invoking_a_osgi 45
- 46. OSGi & EJB Client OSGi Service Registry login Export-Package API register Export-EJB Impl Container-managed JPA LoadData http://weblogs.java.net/blog/ss141213/archive/2010/03/30/ejb-osgi-service-demo-eclipsecon 46
- 47. OSGi + EJB • Export EJB as OSGi services Export-EJB: ALL/None/<names> • Pure OSGi components can discover/invoke • Advantages • Declarative security, transaction, CDI, … are available to non-EE components • Tx context from pure OSGi bundle propagates to invoked EJB • Ditto for security and persistence context 47
- 48. OSGi & JMS Export-EJB: None Consumer Destination ConnectionFactory Messages# BundleActivator Producer OSGi Config Admin http://www.java.net/blog/ss141213/archive/2010/04/21/osgijmsmdb-example 48
- 49. Extending GlassFish v3 Using Spring dm Container • Simple Spring bean implementing the service • Invoke the service from a servlet using standard @Resource injection • Single runtime for both Spring and full Java EE http://blogs.oracle.com/dochez/entry/glassfish_v3_extensions_part_4 49
- 50. OSGi + CDI OSGi Export-Package API Service Registry Import-Package Impl Bundle-Activator Import-Package cker ice Client Ser SGiServ @OviceTra Bundle-Activator Filters http://blogs.oracle.com/arungupta/entry/totd_154_dynamic_osgi_services 50
- 51. OSGi + CDI ServiceTracker tracker = new ServiceTracker(context, Hello.class.getName(), null); tracker.open(); Hello hello = (Hello) tracker.getService(); System.out.println(hello.sayHello("Duke")); @Inject @OSGiService(dynamic=true) Hello hello; System.out.println(hello.sayHello("Duke")); • Injected reference is never null because of CDI proxies 51
- 52. OSGi + JPA • Enhancement of JPA entities at runtime • Entities + persistence.xml bundled as OSGi bundle • EntityManagerFactory available as @Inject @OSGiService • Shared persistence unit and there by shared second level cache 52
- 53. OSGi + EE Resources • Define a DataSource, JavaMail, or JMS resource available in Admin Console • Corresponding OSGi service is already available • Resource/Services are dynamic 53
- 54. JavaOne 2010 / EclipseCon 2011 Hands-on Lab NetBeans - http://blogs.oracle.com/arungupta/entry/s313522_instructions_for_osgi_enabled Eclipse - http://blogs.oracle.com/arungupta/entry/screencast_38_developing_osgi_enabled 54
- 55. References • oracle.com/javaee • glassfish.org • oracle.com/goto/glassfish • blogs.oracle.com/theaquarium • youtube.com/GlassFishVideos • Follow @glassfish • http://wikis.sun.com/display/GlassFish/OSGi • http://wikis.sun.com/download/attachments/20 9655166/GF-OSGi-Features-1.0.pdf 55
- 56. <Insert Picture Here> OSGi-enabled Java EE Applications in GlassFish Arun Gupta, Java EE & GlassFish Guy blogs.oracle.com/arungupta, @arungupta