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{{Ecl_activities|type=OSGi|type-repo=osgi}}__NOTOC____NOTOC__<h2>Bundels and Java Applications</h2>
# Check out the [https://guest:1673852@zenit.senecac.on.ca/svn/ecl500/Lectures/trunk/w11-osgi-simple-interface/ Service Interface]
# Check out the [https://guest:1673852@zenit.senecac.on.ca/svn/ecl500/Lectures/trunk/w11-osgi-simple-serviceprovider/ Service Provider]
# Check out the [https://guest:1673852@zenit.senecac.on.ca/svn/ecl500/Lectures/trunk/w11-osgi-simple-serviceconsumer/ Service Consumer]
<h3>[[Steps for Building Applications from Bundels]]</h3>
<h4h2>1. Study Bundels and the InterfacesDeclarative Services</h4h2> * # Check out the [httphttps://www.osgi.org/javadoc/r4v42/org/osgi/framework/Bundle.html Bundle]* [httpguest://www1673852@zenit.osgisenecac.org/javadoc/r4v42/org/osgi/framework/BundleContexton.html BundleContext]* [http:ca/svn/www.osgi.orgecl500/javadocLectures/r4v42trunk/org/osgi/framework/BundleActivator.html BundleActivator] <h4>2. Define the Bundle Service Provider</h4><h5> 2.1 Define the Generic Bundle Service Provider</h5> <h5>2.1.1 Define the Java Interface that exposes the services</h5>Let us suppose that you want to define a service that allows the user to find a book from the book isbn. Then the interface should look similare with this one:<source lang="java">package cs.ecl.osgi.simple.bookfinder; public interface BookFinder { Book findBook(int isbn) throws BookNotFoundException;}</source>Define in the same bundle the classes that you need such as: Book and BookNotFoundException<source lang="java">package cs.ecl.osgi.simple.bookfinder; public class Book { private int isbn; private String title; public Book(int isbn, String title) { super(); this.isbn = isbn; this.title = title; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public int getIsbn() { return isbn; } public void setIsbn(int isbn) { this.isbn = isbn; }} package cs.ecl.osgi.simple.bookfinder; public class BookNotFoundException extends Exception { private static final long serialVersionUID = w11-6184839510952070091L; public BookNotFoundException() { super(); } public BookNotFoundException(String arg0) { super(arg0); }}</source> Define in the MANIFEST.MF that cs.ecl.osgi.simple.bookfinder is the '''Exported-Package'''<source lang="xml">Manifest-Version: 1.0Bundle-ManifestVersion: 2Bundle-Name: BookfinderBundle-SymbolicName: cs.ecl.osgi.simple.bookfinderBundle-Version: 1.0.0.qualifierBundledeclarativeservice-RequiredExecutionEnvironment: JavaSE-1.6consumer Declarative Service Consumer]Bundle-Vendor: Seneca College - Eclipse CourseExport-Package# Check out the [https: cs.ecl.osgi.simple.bookfinder</source> <h5>2.2 Define a Concrete Bundle Provider</h5><h6>2.2.1 Define the Activator class</h6><source lang="java">package cs.ecl.osgi.simple.bookfinderservice; import org.osgi.framework.BundleActivator;import org.osgi.framework.BundleContext; import cs.ecl.osgi.simple.bookfinder.BookFinder;import cs.ecl.osgi.simpleguest:1673852@zenit.bookfinderservicesenecac.internalson.BookFinderImplementation; public class Activator implements BundleActivator { private static BundleContext context; static BundleContext getContext() { return context; } public void start(BundleContext bundleContext) throws Exception { Activator.context = bundleContext; BookFinder bookService = new BookFinderImplementation(); context.registerService(BookFinder.class.getName(), bookService, null); System.out.println(" Bookfinder service registered "); } public void stop(BundleContext bundleContext) throws Exception { Activator.context = null; System.out.println(" Bookfinder service stopped "); }}</source> <h6>2.2.1 Define the internal implementation class (the class BookFinderImplementation <u>will not be exposed to the outside world<ca/u>)<svn/h6> <source lang="java">package cs.ecl.osgi.simple.bookfinderservice.internals; import cs.ecl.osgi.simple.bookfinder.Book;import cs.ecl.osgi.simple.bookfinder.BookFinder;import cs.ecl.osgi.simple.bookfinder.BookNotFoundException; public class BookFinderImplementation implements BookFinder { private static final Book[] BOOKS = new Book[] { new Book(1234, "Java Programming Language"), new Book(5678, "OSGi") }; public Book findBook(int isbn) throws BookNotFoundException { Book found = null; for (Book b : BOOKS) if (b.getIsbn() == isbn) { found = b; break; } if (found == null) throw new BookNotFoundException("No book with isbn = " + isbn); return found; }}ecl500/Lectures/This could be any implementation: database, file system, distributed, etc. <trunk/source> Define in the MANIFEST.MF for cs.ecl.osgi.simple.bookfinderservice<source lang="xml">Manifest-Version: 1.0Bundle-ManifestVersion: 2Bundle-Name: BookfinderserviceBundle-SymbolicName: cs.ecl.osgi.simple.bookfinderserviceBundle-Version: 1.0.0.qualifierBundle-Activator: cs.ecl.osgi.simple.bookfinderservice.ActivatorBundle-ActivationPolicy: lazyBundle-RequiredExecutionEnvironment: JavaSEw11-1.6Import-Package: org.osgi.framework;version="1.3.0"Bundle-Vendor: Seneca College - Eclipse CourseExport-Package: cs.ecl.osgi.simple.bookfinderserviceRequire-Bundle: cs.ecl.osgi.simple.bookfinder;bundledeclarativeservice-version="1.0.0"provider Declarative Service Provider]</sourceh3> The bundle export the package cs.ecl.osgi.simple.bookfinderservice Meanwhile, the implementation package - cs.ecl.osgi.simple.bookfinderservice.internals - <strong>is hidden to the outside world and can be change dynamically[[Steps for Building Declarative Services]]</strongh3> and can be changed dynamically anytime a better implementation is created. The bundle requires the osgi framework and the interface bundle (e.g. bookfinder bundle) : Require-Bundle: cs.ecl.osgi.simple.bookfinder;bundle-version="1.0.0": Import-Package: org.osgi.framework;version="1.3.0" The bundle export its service (for instance, the bood finder service - cs.ecl.osgi.simple.bookfinderservice) : Export-Package: cs.ecl.osgi.simple.bookfinderservice
